WAC
296-62-07544 Appendix B--Sampling strategy and analytical
methods for formaldehyde.
(1) To protect the health of employees, exposure
measurements must be unbiased and representative of employee exposure.
The proper measurement of employee exposure requires more than
a token commitment on the part of the employer. WISHA's mandatory
requirements establish a baseline; under the best of circumstances
all questions regarding employee exposure will be answered. Many
employers, however, will wish to conduct more extensive monitoring
before undertaking expensive commitments, such as engineering
controls to assure that the modifications are truly necessary.
The following sampling strategy, which was developed at NIOSH
by Nelson A. Leidel, Kenneth A. Busch, and Jeremiah R. Lynch and
described in NIOSH publication No. 77-173 (Occupational Exposure
Sampling Strategy Manual) will assist the employer in developing
a strategy for determining the exposure of his or her employees.
(2) There is no one correct way to determine employee
exposure. Obviously, measuring the exposure of every employee
exposed to formaldehyde will provide the most information on any
given day. Where few employees are exposed, this may be a practical
solution. For most employers, however, use of the following strategy
will give just as much information at less cost.
(3) Exposure data collected on a single day will
not automatically guarantee the employer that his or her workplace
is always in compliance with the formaldehyde standard. This does
not imply, however, that it is impossible for an employer to be
sure that his or her worksite is in compliance with the standard.
Indeed, a properly designed sampling strategy showing
that all employees are exposed below the PELs, at least with a
ninety-five percent certainty, is compelling evidence that the
exposure limits are being achieved provided that measurements
are conducted using valid sampling strategy and approved analytical
methods.
(4) There are two PELs, the TWA concentration and
the STEL.
(a) Most employers will find that one of these
two limits is more critical in the control of their operations,
and WISHA expects that the employer will concentrate monitoring
efforts on the critical component.
(b) If the more difficult exposure is controlled,
this information, along with calculations to support the assumptions,
should be adequate to show that the other exposure limit is
also being achieved.
(5) Sampling strategy.
(a) Determination of the need for exposure measurements.
(b) The employer must determine whether employees
may be exposed to concentrations in excess of the action level.
This determination becomes the first step in an employee exposure
monitoring program that minimizes employer sampling burdens
while providing adequate employee protection.
(c) If employees may be exposed above the action
level, the employer must measure exposure. Otherwise, an objective
determination that employee exposure is low provides adequate
evidence that exposure potential has been examined.
(d) The employer should examine all available
relevant information, e.g., insurance company and trade association
data and information from suppliers or exposure data collected
from similar operations.
(e) The employer may also use previously-conducted
sampling including area monitoring. The employer must make a
determination relevant to each operation although this need
not be on a separate piece of paper.
(f) If the employer can demonstrate conclusively
that no employee is exposed above the action level or the STEL
through the use of objective data, the employer need proceed
no further on employee exposure monitoring until such time that
conditions have changed and the determination is no longer valid.
(g) If the employer cannot determine that employee
exposure is less than the action level and the STEL, employee
exposure monitoring will have to be conducted.
(6) Workplace material survey.
(a) The primary purpose of a survey of raw material
is to determine if formaldehyde is being used in the work environment
and if so, the conditions under which formaldehyde is being
used.
(b) The first step is to tabulate all situations
where formaldehyde is used in a manner such that it may be released
into the workplace atmosphere or contaminate the skin. This
information should be available through analysis of company
records and information on the MSDSs available through provisions
of this standard and the hazard communication standard.
(c) If there is an indication from materials handling
records and accompanying MSDSs that formaldehyde is being used
in the following types of processes or work operations, there
may be a potential for releasing formaldehyde into the workplace
atmosphere:
(i) Any operation that involves grinding, sanding,
sawing, cutting, crushing, screening, sieving, or any other
manipulation of material that generates formaldehyde-bearing
dust.
(ii) Any processes where there have been employee
complaints or symptoms indicative of exposure to formaldehyde.
(iii) Any liquid or spray process involving
formaldehyde.
(iv) Any process that uses formaldehyde in preserved
tissue.
(v) Any process that involves the heating of
a formaldehyde-bearing resin.
Processes and work operations that use formaldehyde
in these manners will probably require further investigation
at the worksite to determine the extent of employee monitoring
that should be conducted.
(7) Workplace observations.
(a) To this point, the only intention has been
to provide an indication as to the existence of potentially
exposed employees. With this information, a visit to the workplace
is needed to observe work operations, to identify potential
health hazards, and to determine whether any employees may be
exposed to hazardous concentrations of formaldehyde.
(b) In many circumstances, sources of formaldehyde
can be identified through the sense of smell. However, this
method of detection should be used with caution because of olfactory
fatigue.
(c) Employee location in relation to source of
formaldehyde is important in determining if an employee may
be significantly exposed to formaldehyde. In most instances,
the closer a worker is to the source, the higher the probability
that a significant exposure will occur.
(d) Other characteristics should be considered.
Certain high temperature operations give rise to higher evaporation
rates. Locations of open doors and windows provide natural ventilation
that tend to dilute formaldehyde emissions. General room ventilation
also provides a measure of control.
(8) Calculation of potential exposure concentrations.
(a) By knowing the ventilation rate in a workplace
and the quantity of formaldehyde generated, the employer may
be able to determine by calculation if the PELs might be exceeded.
(b) To account for poor mixing of formaldehyde
into the entire room, locations of fans and proximity of employees
to the work operation, the employer must include a safety factor.
(c) If an employee is relatively close to a source,
particularly if he or she is located downwind, a safety factor
of one hundred may be necessary.
(d) For other situations, a factor of ten may
be acceptable. If the employer can demonstrate through such
calculations that employee exposure does not exceed the action
level or the STEL, the employer may use this information as
objective data to demonstrate compliance with the standard.
(9) Sampling strategy.
(a) Once the employer determines that there is
a possibility of substantial employee exposure to formaldehyde,
the employer is obligated to measure employee exposure.
(b) The next step is selection of a maximum risk
employee. When there are different processes where employees
may be exposed to formaldehyde, a maximum risk employee should
be selected for each work operation.
(c) Selection of the maximum risk employee requires
professional judgment. The best procedure for selecting the
maximum risk employee is to observe employees and select the
person closest to the source of formaldehyde. Employee mobility
may affect this selection; e.g., if the closest employee is
mobile in his tasks, he may not be the maximum risk employee.
Air movement patterns and differences in work habits will also
affect selection of the maximum risk employee.
(d) When many employees perform essentially the
same task, a maximum risk employee cannot be selected. In this
circumstance, it is necessary to resort to random sampling of
the group of workers. The objective is to select a subgroup
of adequate size so that there is a high probability that the
random sample will contain at least one worker with high exposure
if one exists. The number of persons in the group influences
the number that need to be sampled to ensure that at least one
individual from the highest ten percent exposure group is contained
in the sample. For example, to have ninety percent confidence
in the results, if the group size is ten, nine should be sampled;
for fifty, only eighteen need to be sampled.
(e) If measurement shows exposure to formaldehyde
at or above the action level or the STEL, the employer needs
to identify all other employees who may be exposed at or above
the action level or STEL and measure or otherwise accurately
characterize the exposure of these employees.
(f) Whether representative monitoring or random
sampling are conducted, the purpose remains the same to determine
if the exposure of any employee is above the action level. If
the exposure of the most exposed employee is less than the action
level and the STEL, regardless of how the employee is identified,
then it is reasonable to assume that measurements of exposure
of the other employees in that operation would be below the
action level and the STEL.
(10) Exposure measurements.
(a) There is no “best” measurement
strategy for all situations. Some elements to consider in developing
a strategy are:
(i) Availability and cost of sampling equipment;
(ii) Availability and cost of analytic facilities;
(iii) Availability and cost of personnel to
take samples;
(iv) Location of employees and work operations;
(v) Intraday and interday variations in the
process;
(vi) Precision and accuracy of sampling and
analytic methods; and
(vii) Number of samples needed.
(b) Samples taken for determining compliance with
the STEL differ from those that measure the TWA concentration
in important ways. STEL samples are best taken in a nonrandom
fashion using all available knowledge relating to the area,
the individual, and the process to obtain samples during periods
of maximum expected concentrations. At least three measurements
on a shift are generally needed to spot gross errors or mistakes;
however, only the highest value represents the STEL.
(c) If an operation remains constant throughout
the workshift, a much greater number of samples would need to
be taken over the thirty-two discrete nonoverlapping periods
in an 8-hour workshift to verify compliance with a STEL. If
employee exposure is truly uniform throughout the workshift,
however, an employer in compliance with the 1 ppm TWA would
be in compliance with the 2 ppm STEL, and this determination
can probably be made using objective data.
(11) Need to repeat the monitoring strategy.
(a) Interday and intraday fluctuations in employee
exposure are mostly influenced by the physical processes that
generate formaldehyde and the work habits of the employee. Hence,
in-plant process variations influence the employer's determination
of whether or not additional controls need to be imposed. Measurements
that employee exposure is low on a day that is not representative
of worst conditions may not provide sufficient information to
determine whether or not additional engineering controls should
be installed to achieve the PELs.
(b) The person responsible for conducting sampling
must be aware of systematic changes which will negate the validity
of the sampling results. Systematic changes in formaldehyde
exposure concentration for an employee can occur due to:
(i) The employee changing patterns of movement
in the workplace;
(ii) Closing of plant doors and windows;
(iii) Changes in ventilation from season to
season;
(iv) Decreases in ventilation efficiency or
abrupt failure of engineering control equipment; and
(v) Changes in the production process or work
habits of the employee.
(c) Any of these changes, if they may result in
additional exposure that reaches the next level of action (i.e.,
0.5 or 1.0 ppm as an 8-hour average or 2 ppm over fifteen minutes)
require the employer to perform additional monitoring to reassess
employee exposure.
(d) A number of methods are suitable for measuring
employee exposure to formaldehyde or for characterizing emissions
within the worksite. The preamble to this standard describes
some methods that have been widely used or subjected to validation
testing. A detailed analytical procedure derived from the WISHA
Method A.C.R.O. for acrolein and formaldehyde is presented below
for informational purposes.
(e) Inclusion of WISHA's method in this appendix
in no way implies that it is the only acceptable way to measure
employee exposure to formaldehyde. Other methods that are free
from significant interferences and that can determine formaldehyde
at the permissible exposure limits within .±25 percent of the
“true” value at the ninety-five percent confidence
level are also acceptable. Where applicable, the method should
also be capable of measuring formaldehyde at the action level
to ±35 percent of the “true” value with a ninety-five
percent confidence level. WISHA encourages employers to choose
methods that will be best for their individual needs. The employer
must exercise caution, however, in choosing an appropriate method
since some techniques suffer from interferences that are likely
to be present in workplaces of certain industry sectors where
formaldehyde is used.
(12) WISHA's analytical laboratory method.
A.C.R.O. (also use methods F.O.R.M. and F.O.R.M.
2 when applicable).
(a) Matrix: Air.
(b) Target concentration: 1 ppm (1.2 mg/m3).
(c) Procedures: Air samples are collected by drawing
known volumes of air through sampling tubes containing XAD-2
adsorbent which have been coated with 2-(hydroxymethyl) piperidine.
The samples are desorbed with toluene and then analyzed by gas
chromatography using a nitrogen selective detector.
(d) Recommended sampling rate and air volumes:
0.1 L/min and 24 L.
(f) Standard error of estimate at the target concentration:
7.3%.
(g) Status of the method: A sampling and analytical
method that has been subjected to the established evaluation
procedures of the organic methods evaluation branch.
(h) Date: March, 1985.
(13) General discussion.
(a) Background: The current WISHA method for collecting
acrolein vapor recommends the use of activated 13X molecular
sieves. The samples must be stored in an ice bath during and
after sampling and also they must be analyzed within forty-eight
hours of collection. The current WISHA method for collecting
formaldehyde vapor recommends the use of bubblers containing
ten percent methanol in water as the trapping solution.
(b) This work was undertaken to resolve the sample
stability problems associated with acrolein and also to eliminate
the need to use bubblers to sample formaldehyde. A goal of this
work was to develop and/or to evaluate a common sampling and
analytical procedure for acrolein and formaldehyde.
(c) NIOSH has developed independent methodologies
for acrolein and formaldehyde which recommend the use of reagent-coated
adsorbent tubes to collect the aldehydes as stable derivatives.
The formaldehyde sampling tubes contain Chromosorb 102 adsorbent
coated with N-benzylethanolamine (BEA) which reacts with formaldehyde
vapor to form a stable oxazolidine compound. The acrolein sampling
tubes contain XAD-2 adsorbent coated with 2-(hydroxymethyl)
piperidine (2-HMP) which reacts with acrolein vapor to form
a different, stable oxazolidine derivative. Acrolein does not
appear to react with BEA to give a suitable reaction product.
Therefore, the formaldehyde procedure cannot provide a common
method for both aldehydes. However, formaldehyde does react
with 2-HMP to form a very suitable reaction product. It is the
quantitative reaction of acrolein and formaldehyde with 2-HMP
that provides the basis for this evaluation.
(d) This sampling and analytical procedure is
very similar to the method recommended by NIOSH for acrolein.
Some changes in the NIOSH methodology were necessary to permit
the simultaneous determination of both aldehydes and also to
accommodate WISHA laboratory equipment and analytical techniques.
(14) Limit-defining parameters: The analyte air
concentrations reported in this method are based on the recommended
air volume for each analyte collected separately and a desorption
volume of 1 mL. The amounts are presented as acrolein and/or formaldehyde,
even though the derivatives are the actual species analyzed.
(15) Detection limits of the analytical procedure:
The detection limit of the analytical procedure was 386 pg per
injection for formaldehyde. This was the amount of analyte which
gave a peak whose height was about five times the height of the
peak given by the residual formaldehyde derivative in a typical
blank front section of the recommended sampling tube.
(16) Detection limits of the overall procedure:
The detection limits of the overall procedure were 482 ng per
sample (16 ppb or 20 µg/m3 for formaldehyde). This
was the amount of analyte spiked on the sampling device which
allowed recoveries approximately equal to the detection limit
of the analytical procedure.
(17) Reliable quantitation limits:
(a) The reliable quantitation limit was 482 ng
per sample (16 ppb or 20 µg/m3) for formaldehyde.
These were the smallest amounts of analyte which could be quantitated
within the limits of a recovery of at least seventy-five percent
and a precision (±1.96 SD) of ±25% or better.
(b) The reliable quantitation limit and detection
limits reported in the method are based upon optimization of
the instrument for the smallest possible amount of analyte.
When the target concentration of an analyte is exceptionally
higher than these limits, they may not be attainable at the
routine operating parameters.
(18) Sensitivity: The sensitivity of the analytical
procedure over concentration ranges representing 0.4 to 2 times
the target concentration, based on the recommended air volumes,
was seven thousand five hundred eighty-nine area units per mg/mL
for formaldehyde. This value was determined from the slope of
the calibration curve. The sensitivity may vary with the particular
instrument used in the analysis.
(19) Recovery: The recovery of formaldehyde from
samples used in an eighteen-day storage test remained above ninety-two
percent when the samples were stored at ambient temperature. These
values were determined from regression lines which were calculated
from the storage data. The recovery of the analyte from the collection
device must be at least seventy-five percent following storage.
(20) Precision (analytical method only): The pooled
coefficient of variation obtained from replicate determinations
of analytical standards over the range of 0.4 to 2 times the target
concentration was 0.0052 for formaldehyde ((d)(C)(iii) of this
subsection).
(21) Precision (overall procedure): The precision
at the ninety-five percent confidence level for the ambient temperature
storage tests was ±14.3% for formaldehyde. These values each include
an additional ±5% for sampling error. The overall procedure must
provide results at the target concentrations that are ±25% at
the ninety-five percent confidence level.
(22) Reproducibility: Samples collected from controlled
test atmospheres and a draft copy of this procedure were given
to a chemist unassociated with this evaluation. The formaldehyde
samples were analyzed following fifteen days storage. The average
recovery was 96.3% and the standard deviation was 1.7%.
(23) Advantages:
(a) The sampling and analytical procedures permit
the simultaneous determination of acrolein and formaldehyde.
(b) Samples are stable following storage at ambient
temperature for at least eighteen days.
(24) Disadvantages: None.
(25) Sampling procedure.
(a) Apparatus:
(i) Samples are collected by use of a personal
sampling pump that can be calibrated to within ±5% of the
recommended 0.1 L/min sampling rate with the sampling tube
in line.
(ii) Samples are collected with laboratory prepared
sampling tubes. The sampling tube is constructed of silane
treated glass and is about 8-cm long. The ID is 4 mm and the
OD is 6 mm. One end of the tube is tapered so that a glass
wool end plug will hold the contents of the tube in place
during sampling. The other end of the sampling tube is open
to its full 4-mm ID to facilitate packing of the tube. Both
ends of the tube are fire-polished for safety.
The tube is packed with a 75-mg backup section,
located nearest the tapered end and a 150-mg sampling section
of pretreated XAD-2 adsorbent which has been coated with 2-HMP.
The two sections of coated adsorbent are separated and retained
with small plugs of silanized glass wool. Following packing,
the sampling tubes are sealed with two 7/32 inch OD plastic
and caps. Instructions for the pretreatment and the coating
of XAD-2 adsorbent are presented in (d) of this subsection.
(b) Sampling tubes, similar to those recommended
in this method, are marketed by Supelco, Inc. These tubes were
not available when this work was initiated; therefore, they
were not evaluated.
(26) Reagents: None required.
(27) Technique:
(a) Properly label the sampling tube before sampling
and then remove the plastic end caps.
(b) Attach the sampling tube to the pump using
a section of flexible plastic tubing such that the large, front
section of the sampling tube is exposed directly to the atmosphere.
Do not place any tubing ahead of the sampling tube. The sampling
tube should be attached in the worker's breathing zone in a
vertical manner such that it does not impede work performance.
(c) After sampling for the appropriate time, remove
the sampling tube from the pump and then seal the tube with
plastic end caps.
(d) Include at least one blank for each sampling
set. The blank should be handled in the same manner as the samples
with the exception that air is not drawn through it.
(e) List any potential interferences on the sample
data sheet.
(a) Breakthrough was defined as the relative amount
of analyte found on a backup sample in relation to the total
amount of analyte collected on the sampling train.
(b) For formaldehyde collected from test atmospheres
containing six times the PEL, the average five percent breakthrough
air volume was 41 L. The sampling rate was 0.1 L/min and the
average mass of formaldehyde collected was 250 mg.
(29) Desorption efficiency: No desorption efficiency
corrections are necessary to compute air sample results because
analytical standards are prepared using coated adsorbent. Desorption
efficiencies were determined, however, to investigate the recoveries
of the analytes from the sampling device. The average recovery
over the range of 0.4 to 2 times the target concentration, based
on the recommended air volumes, was 96.2% for formaldehyde. Desorption
efficiencies were essentially constant over the ranges studied.
(30) Recommended air volume and sampling rate:
(a) The recommended air volume for formaldehyde
is 24 L.
(b) The recommended sampling rate is 0.1 L/min.
(31) Interferences:
(a) Any collected substance that is capable of
reacting with 2-HMP and thereby depleting the derivatizing agent
is a potential interference. Chemicals which contain a carbonyl
group, such as acetone, may be capable of reacting with 2-HMP.
(b) There are no other known interferences to
the sampling method.
(32) Safety precautions:
(a) Attach the sampling equipment to the worker
in such a manner that it will not interfere with work performance
or safety.
(b) Follow all safety practices that apply to
the work area being sampled.
(33) Analytical procedure.
(a) Apparatus:
(i) A gas chromatograph (GC), equipped with
a nitrogen selective detector. A Hewlett-Packard model 5840A
GC fitted with a nitrogen phosphorus flame ionization detector
(NPD) was used for this evaluation. Injections were performed
using a Hewlett-Packard model 7671A automatic sampler.
(ii) A GC column capable of resolving the analytes
from any interference. A 6 ft x 1/4 in OD (2mm ID) glass GC
column containing 10% UCON 50-HB-5100 + 2% KOH on 80/100 mesh
Chromosorb W-AW was used for the evaluation. Injections were
performed on-column.
(iii) Vials, glass 2-mL with Teflonlined caps.
(iv) Volumetric flasks, pipets, and syringes
for preparing standards, making dilutions, and performing
injections.
(b) Reagents:
(i) Toluene and dimethylformamide. Burdick and
Jackson solvents were used in this evaluation.
(ii) Helium, hydrogen, and air, GC grade.
(iii) Formaldehyde, thirty-seven percent by
weight, in water. Aldrich Chemical, ACS Reagent Grade formaldehyde
was used in this evaluation.
(iv) Amberlite XAD-2 adsorbent coated with 2-(hydroxymethyl)
piperidine (2-HMP), 10% by weight ((d) of this subsection).
(v) Desorbing solution with internal standard.
This solution was prepared by adding 20 uL of dimethylformamide
to 100 mL of toluene.
(c) Standard preparation:
(i) Formaldehyde: Prepare stock standards by
diluting known volumes of thirty-seven percent formaldehyde
solution with methanol. A procedure to determine the formaldehyde
content of these standards is presented in (d) of this subsection.
A standard containing 7.7 mg/mL formaldehyde was prepared
by diluting 1 mL of the thirty-seven percent reagent to 50
mL with methanol.
(ii) It is recommended that analytical standards
be prepared about sixteen hours before the air samples are
to be analyzed in order to ensure the complete reaction of
the analytes with 2-HMP. However, rate studies have shown
the reaction to be greater than ninety-five percent complete
after four hours. Therefore, one or two standards can be analyzed
after this reduced time if sample results are outside the
concentration range of the prepared standards.
(iii) Place 150-mg portions of coated XAD-2
adsorbent, from the same lot number as used to collect the
air samples, into each of several glass 2-mL vials. Seal each
vial with a Teflonlined cap.
(iv) Prepare fresh analytical standards each
day by injecting appropriate amounts of the diluted analyte
directly onto 150-mg portions of coated adsorbent. It is permissible
to inject both acrolein and formaldehyde on the same adsorbent
portion. Allow the standards to stand at room temperature.
A standard, approximately the target levels, was prepared
by injecting 11 uL of the acrolein and 12 uL of the formaldehyde
stock standards onto a single coated XAD-2 adsorbent portion.
(v) Prepare a sufficient number of standards
to generate the calibration curves. Analytical standard concentrations
should bracket sample concentrations. Thus, if samples are
not in the concentration range of the prepared standards,
additional standards must be prepared to determine detector
response.
(vi) Desorb the standards in the same manner
as the samples following the sixteen-hour reaction time.
(d) Sample preparation:
(i) Transfer the 150-mg section of the sampling
tube to a 2-mL vial. Place the 75-mg section in a separate
vial. If the glass wool plugs contain a significant number
of dsorbent beads, place them with the appropriate sampling
tube section. Discard the glass wool plugs if they do not
contain a significant number of adsorbent beads.
(ii) Add 1 mL of desorbing solution to each
vial.
(iii) Seal the vials with Teflonlined caps and
then allow them to desorb for one hour. Shake the vials by
hand with vigorous force several times during the desorption
time.
(iv) Save the used sampling tubes to be cleaned
and recycled.
(e) Analysis:
(f) GC conditions.
(34) Column temperature:
(a) Bi-level temperature program.
(i) First level: 100°C to 140C at 4°C/min following
completion of the first level.
(ii) Second level: 140°C to 180°C at 20°C/min
following completion of the first level.
(b) Isothermal period: Hold column at 180°C until
the recorder pen returns to baseline (usually about twenty-five
minutes after injection).
(c) Injector temperature: 180°C.
(d) Helium flow rate: 30 mL/min (detector response
will be reduced if nitrogen is substituted for helium carrier
gas).
(e) Injection volume: 51 0.8 uL.
(f) GC column: Six-ft x 1/4-in OD (2 mm ID) glass
GC column containing 10% UCON 50-HB-5100NZG651+512% KOH on 80/100
Chromosorb W-AW.
(g) NPD conditions:
(i) Hydrogen flow rate: 3 mL/min.
(ii) Air flow rate: 50 mL/min.
(h) Detector temperature: 275 5151C.
(i) Use a suitable method, such as electronic
integration, to measure detector response.
(ii) Use an internal standard method to prepare
the calibration curve with several standard solutions of different
concentrations. Prepare the calibration curve daily. Program
the integrator to report results in mg/mL.
(iii) Bracket sample concentrations with standards.
(iv) Interferences (analytical).
(A) Any compound with the same general retention
time as the analytes and which also gives a detector response
is a potential interference. Possible interferences should
be reported to the laboratory with submitted samples by
the industrial hygienist.
(B) GC parameters (temperature, column, etc.),
may be changed to circumvent interferences.
(C) A useful means of structure designation
is GC/MS. It is recommended this procedure be used to confirm
samples whenever possible.
(D) The coated adsorbent usually contains
a very small amount of residual formaldehyde derivative.
(i) Calculations:
(i) Results are obtained by use of calibration
curves. Calibration curves are prepared by plotting detector
response against concentration for each standard. The best
line through the data points is determined by curve fitting.
(ii) The concentration, in mg/mL, for a particular
sample is determined by comparing its detector response to
the calibration curve. If either of the analytes is found
on the backup section, it is added to the amount found on
the front section. Blank corrections should be performed before
adding the results together.
(iii) The acrolein and/or formaldehyde air concentration
can be expressed using the following equation:
Mg/m3 = (A)(B)/C.
where A = µg/mL from 3.7.2, B = desorption
volume, and C = L of air sampled.
No desorption efficiency corrections are required.
(iv) The following equation can be used to convert
results in mg/m51351 to ppm.
ppm = (mg/m3)(24.45)/MW
where mg/m3 = result from 3.7.3,
24.45 = molar volume of an ideal gas at 760 mm Hg and 25
5151C, MW = molecular weight (Formaldehyde = 30.0).
(j) Backup data. Backup data on detection limits,
reliable quantitation limits, sensitivity and precision of the
analytical method, breakthrough, desorption efficiency, storage,
reproducibility, and generation of test atmospheres are available
in OSHA Method 52, developed by the Organics Methods Evaluation
Branch, OSHA Analytical Laboratory, Salt Lake City, Utah.
(k) Procedure to coat XAD-2 adsorbent with 2-HMP:
(i) Apparatus: Soxhlet extraction apparatus,
rotary evaporation apparatus, vacuum dessicator, 1-L vacuum
flask, 1-L round-bottomed evaporative flask, 1-L Erlenmeyer
flask, 250-mL Buchner funnel with a coarse fritted disc, etc.
(ii) Reagents:
(A) Methanol, isooctane, and toluene.
(B) (Hydroxymethyl) piperidine.
(C) Amberlite XAD-2 nonionic polymeric adsorbent,
twenty to sixty mesh, Aldrich Chemical XAD-2 was used in
this evaluation.
(l) Procedure: Weigh 125 g of crude XAD-2 adsorbent
into a 1-L Erlenmeyer flask. Add about 200 mL of water to the
flask and then swirl the mixture to wash the adsorbent. Discard
any adsorbent that floats to the top of the water and then filter
the mixture using a fritted Buchner funnel. Air dry the adsorbent
for two minutes. Transfer the adsorbent back to the Erlenmeyer
flask and then add about 200 mL of methanol to the flask. Swirl
and then filter the mixture as before. Transfer the washed adsorbent
back to the Erlenmeyer flask and then add about 200 mL of methanol
to the flask. Swirl and then filter the mixture as before. Transfer
the washed adsorbent to a 1-L round-bottomed evaporative flask,
add 13 g of 2-HMP and then 200 mL of methanol, swirl the mixture
and then allow it to stand for one hour. Remove the methanol
at about 40oC and reduced pressure using a rotary evaporation
apparatus. Transfer the coated adsorbent to a suitable container
and store it in a vacuum desiccator at room temperature overnight.
Transfer the coated adsorbent to a Soxhlet extractor and then
extract the material with toluene for about twenty-four hours.
Discard the contaminated toluene, add methanol in its place
and then continue the Soxhlet extraction for an additional four
hours. Transfer the adsorbent to a weighted 1-L round-bottom
evaporative flask and remove the methanol using the rotary evaporation
apparatus. Determine the weight of the adsorbent and then add
an amount of 2-HMP, which is ten percent by weight of the adsorbent.
Add 200 mL of methanol and then swirl the mixture. Allow the
mixture to stand for one hour. Remove the methanol by rotary
evaporation. Transfer the coated adsorbent to a suitable container
and store it in a vacuum dessicator until all traces of solvents
are gone. Typically, this will take two to three days. The coated
adsorbent should be protected from contamination. XAD-2 adsorbent
treated in this manner will probably not contain residual acrolein
derivative. However, this adsorbent will often contain residual
formaldehyde derivative levels of about 0.1 mg per 150 mg of
adsorbent. If the blank values for a batch of coated adsorbent
are too high, then the batch should be returned to the Soxhlet
extractor, extracted with toluene again and then recoated. This
process can be repeated until the desired blank levels are attained.
The coated adsorbent is now ready to be packed
into sampling tubes. The sampling tubes should be stored in
a sealed container to prevent contamination. Sampling tubes
should be stored in the dark at room temperature. The sampling
tubes should be segregated by coated adsorbent lot number. A
sufficient amount of each lot number of coated adsorbent should
be retained to prepare analytical standards for use with air
samples from that lot number.
(m) A procedure to determine formaldehyde by acid
titration:
(i) Standardize the 0.1 N HC1 solution using
sodium carbonate and methyl orange indicator.
(ii) Place 50 mL of 0.1 M sodium sulfite and
three drops of thymophthalein indicator into a 250-mL Erlenmeyer
flask. Titrate the contents of the flask to a colorless endpoint
with 0.1 N HC1 (usually one or two drops is sufficient). Transfer
10 mL of the formaldehyde/methanol solution ((b)(iii)(A) of
this subsection) into the same flask and titrate the mixture
with 0.1 N HC1, again, to a colorless endpoint. The formaldehyde
concentration of the standard may be calculated by the following
equation:
acid titer x acid normality x 30.0
Formaldehyde, mg/mL =
mL of Sample
(iii) This method is based on the quantitative
liberation of sodium hydroxide when formaldehyde reacts with
sodium sulfite to form the formaldehyde-bisulfite addition
product. The volume of sample may be varied depending on the
formaldehyde content but the solution to be titrated must
contain excess sodium sulfite. Formaldehyde solutions containing
substantial amounts of acid or base must be neutralized before
analysis.
(1) Health hazards. The occupational health hazards
of formaldehyde are primarily due to its toxic effects after inhalation,
after direct contact with the skin or eyes by formaldehyde in
liquid or vapor form, and after ingestion.
(2) Toxicology.
(a) Acute effects of exposure.
(i) Inhalation (breathing): Formaldehyde is
highly irritating to the upper airways. The concentration
of formaldehyde that is immediately dangerous to life and
health is 100 ppm. Concentrations above 50 ppm can cause severe
pulmonary reactions within minutes. These include pulmonary
edema, pneumonia, and bronchial irritation which can result
in death. Concentrations above 5 ppm readily cause lower airway
irritation characterized by cough, chest tightness, and wheezing.
There is some controversy regarding whether formaldehyde gas
is a pulmonary sensitizer which can cause occupational asthma
in a previously normal individual. Formaldehyde can produce
symptoms of bronchial asthma in humans. The mechanism may
be either sensitization of the individual by exposure to formaldehyde
or direct irritation by formaldehyde in persons with preexisting
asthma. Upper airway irritation is the most common respiratory
effect reported by workers and can occur over a wide range
of concentrations, most frequently above 1 ppm. However, airway
irritation has occurred in some workers with exposures to
formaldehyde as low as 0.1 ppm. Symptoms of upper airway irritation
include dry or sore throat, itching and burning sensations
of the nose, and nasal congestion. Tolerance to this level
of exposure may develop within one to two hours. This tolerance
can permit workers remaining in an environment of gradually
increasing formaldehyde concentrations to be unaware of their
increasingly hazardous exposure.
(ii) Eye contact: Concentrations of formaldehyde
between 0.05 ppm and 0.5 ppm produce a sensation of irritation
in the eyes with burning, itching, redness, and tearing. Increased
rate of blinking and eye closure generally protects the eye
from damage at these low levels, but these protective mechanisms
may interfere with some workers' work abilities. Tolerance
can occur in workers continuously exposed to concentrations
of formaldehyde in this range. Accidental splash injuries
of human eyes to aqueous solutions of formaldehyde (formalin)
have resulted in a wide range of ocular injuries including
corneal opacities and blindness. The severity of the reactions
have been directly dependent on the concentration of formaldehyde
in solution and the amount of time lapsed before emergency
and medical intervention.
(iii) Skin contact: Exposure to formaldehyde
solutions can cause irritation of the skin and allergic contact
dermatitis. These skin diseases and disorders can occur at
levels well below those encountered by many formaldehyde workers.
Symptoms include erythema, edema, and vesiculation or hives.
Exposure to liquid formalin or formaldehyde vapor can provoke
skin reactions in sensitized individuals even when airborne
concentrations of formaldehyde are well below 1 ppm.
(iv) Ingestion: Ingestion of as little as 30
ml of a thirty-seven percent solution of formaldehyde (formalin)
can result in death. Gastrointestinal toxicity after ingestion
is most severe in the stomach and results in symptoms which
can include nausea, vomiting, and severe abdominal pain. Diverse
damage to other organ systems including the liver, kidney,
spleen, pancreas, brain, and central nervous systems can occur
from the acute response to ingestion of formaldehyde.
(b) Chronic effects of exposure. Long-term exposure
to formaldehyde has been shown to be associated with an increased
risk of cancer of the nose and accessory sinuses, nasopharyngeal
and oropharyngeal cancer, and lung cancer in humans. Animal
experiments provide conclusive evidence of a causal relationship
between nasal cancer in rats and formaldehyde exposure. Concordant
evidence of carcinogenicity includes DNA binding, genotoxicity
in short-term tests, and cytotoxic changes in the cells of the
target organ suggesting both preneoplastic changes and a dose-rate
effect. Formaldehyde is a complete carcinogen and appears to
exert an effect on at least two stages of the carcinogenic process.
(3) Surveillance considerations.
(a) History.
(i) Medical and occupational history: Along
with its acute irritative effects, formaldehyde can cause
allergic sensitization and cancer. One of the goals of the
work history should be to elicit information on any prior
or additional exposure to formaldehyde in either the occupational
or the nonoccupational setting.
(ii) Respiratory history: As noted above, formaldehyde
has recognized properties as an airway irritant and has been
reported by some authors as a cause of occupational asthma.
In addition, formaldehyde has been associated with cancer
of the entire respiratory system of humans. For these reasons,
it is appropriate to include a comprehensive review of the
respiratory system in the medical history. Components of this
history might include questions regarding dyspnea on exertion,
shortness of breath, chronic airway complaints, hyperreactive
airway disease, rhinitis, bronchitis, bronchiolitis, asthma,
emphysema, respiratory allergic reaction, or other preexisting
pulmonary disease.
In addition, generalized airway hypersensitivity
can result from exposures to a single sensitizing agent. The
examiner should, therefore, elicit any prior history of exposure
to pulmonary irritants, and any short-term or long-term effects
of that exposure.
Smoking is known to decrease mucociliary clearance
of materials deposited during respiration in the nose and
upper airways. This may increase a worker's exposure to inhaled
materials such as formaldehyde vapor. In addition, smoking
is a potential confounding factor in the investigation of
any chronic respiratory disease, including cancer. For these
reasons, a complete smoking history should be obtained.
(iii) Skin disorders: Because of the dermal
irritant and sensitizing effects of formaldehyde, a history
of skin disorders should be obtained. Such a history might
include the existence of skin irritation, previously documented
skin sensitivity, and other dermatologic disorders. Previous
exposure to formaldehyde and other dermal sensitizers should
be recorded.
(iv) History of atopic or allergic diseases:
Since formaldehyde can cause allergic sensitization of the
skin and airways, it might be useful to identify individuals
with prior allergen sensitization. A history of atopic disease
and allergies to formaldehyde or any other substances should
also be obtained. It is not definitely known at this time
whether atopic diseases and allergies to formaldehyde or any
other substances should also be obtained. Also it is not definitely
known at this time whether atopic individuals have a greater
propensity to develop formaldehyde sensitivity than the general
population, but identification of these individuals may be
useful for ongoing surveillance.
(v) Use of disease questionnaires: Comparison
of the results from previous years with present results provides
the best method for detecting a general deterioration in health
when toxic signs and symptoms are measured subjectively. In
this way recall bias does not affect the results of the analysis.
Consequently, WISHA has determined that the findings of the
medical and work histories should be kept in a standardized
form for comparison of the year-to-year results.
(b) Physical examination.
(i) Mucosa of eyes and airways: Because of the
irritant effects of formaldehyde, the examining physician
should be alert to evidence of this irritation. A speculum
examination of the nasal mucosa may be helpful in assessing
possible irritation and cytotoxic changes, as may be indirect
inspection of the posterior pharynx by mirror.
(ii) Pulmonary system: A conventional respiratory
examination, including inspection of the thorax and auscultation
and percussion of the lung fields should be performed as part
of the periodic medical examination. Although routine pulmonary
function testing is only required by the standard once every
year for persons who are exposed over the TWA concentration
limit, these tests have an obvious value in investigating
possible respiratory dysfunction and should be used wherever
deemed appropriate by the physician. In cases of alleged formaldehyde-induced
airway disease, other possible causes of pulmonary dysfunction
(including exposures to other substances) should be ruled
out. A chest radiograph may be useful in these circumstances.
In cases of suspected airway hypersensitivity or allergy,
it may be appropriate to use bronchial challenge testing with
formaldehyde or methacholine to determine the nature of the
disorder. Such testing should be performed by or under the
supervision of a physician experienced in the procedures involved.
(iii) Skin: The physician should be alert to
evidence of dermal irritation of sensitization, including
reddening and inflammation, urticaria, blistering, scaling,
formation of skin fissures, or other symptoms. Since the integrity
of the skin barrier is compromised by other dermal diseases,
the presence of such disease should be noted. Skin sensitivity
testing carries with it some risk of inducing sensitivity,
and therefore, skin testing for formaldehyde sensitivity should
not be used as a routine screening test. Sensitivity testing
may be indicated in the investigation of a suspected existing
sensitivity. Guidelines for such testing have been prepared
by the North American Contact Dermatitis Group.
(4) Additional examinations or tests. The physician
may deem it necessary to perform other medical examinations or
tests as indicated. The standard provides a mechanism whereby
these additional investigations are covered under the standard
for occupational exposure to formaldehyde.
(5) Emergencies. The examination of workers exposed
in an emergency should be directed at the organ systems most likely
to be affected. Much of the content of the examination will be
similar to the periodic examination unless the patient has received
a severe acute exposure requiring immediate attention to prevent
serious consequences. If a severe overexposure requiring medical
intervention or hospitalization has occurred, the physician must
be alert to the possibility of delayed symptoms. Followup nonroutine
examinations may be necessary to assure the patient's well-being.
(6) Employer obligations. The employer is required
to provide the physician with the following information: A copy
of this standard and appendices A, C, D, and E; a description
of the affected employee's duties as they relate to his or her
exposure concentration; an estimate of the employee's exposure
including duration (e.g., fifteen hr./wk., three eight-hour shifts,
full-time); a description of any personal protective equipment,
including respirators, used by the employee; and the results of
any previous medical determinations for the affected employee
related to formaldehyde exposure to the extent that this information
is within the employer's control.
(7) Physician's obligations. The standard requires
the employer to obtain a written statement from the physician.
This statement must contain the physician's opinion as to whether
the employee has any medical condition which would place him or
her at increased risk of impaired health from exposure to formaldehyde
or use of respirators, as appropriate. The physician must also
state his opinion regarding any restrictions that should be placed
on the employee's exposure to formaldehyde or upon the use of
protective clothing or equipment such as respirators. If the employee
wears a respirator as a result of his or her exposure to formaldehyde,
the physician's opinion must also contain a statement regarding
the suitability of the employee to wear the type of respirator
assigned. Finally, the physician must inform the employer that
the employee has been told the results of the medical examination
and of any medical conditions which require further explanation
or treatment. This written opinion is not to contain any information
on specific findings or diagnoses unrelated to occupational exposure
to formaldehyde.
The purpose in requiring the examining physician
to supply the employer with a written opinion is to provide the
employer with a medical basis to assist the employer in placing
employees initially, in assuring that their health is not being
impaired by formaldehyde, and to assess the employee's ability
to use any required protective equipment.
WAC
296-62-07548 Appendix D--Nonmandatory medical disease questionnaire.
(1) Identification.
(a) Plant name:
(b) Date:
(c) Employee name:
(d) Social Security number:
(e) Job title:
(f) Birthdate:
(g) Age:
(h) Sex:
(i) Height:
(j) Weight:
(2) Medical history.
(a) Have you ever been in the hospital as a patient?
Yes No
If yes, what kind of problem were you having?
(b) Have you ever had any kind of operation?
Yes No
If yes, what kind?
(c) Do you take any kind of medicine regularly?
Yes No
If yes, what kind?
(d) Are you allergic to any drugs, foods, or chemicals?
Yes No
If yes, what kind of allergy is it?
What causes the allergy?
(e) Have you ever been told that you have asthma,
hayfever, or sinusitis?
Yes No
(f) Have you ever been told that you have emphysema,
bronchitis, or any other respiratory problems?
Yes No
(g) Have you ever been told you had hepatitis?
Yes No
(h) Have you ever been told that you have cirrhosis?
Yes No
(i) Have you ever been told that you had cancer?
Yes No
(j) Have you ever had arthritis or joint pain?
Yes No
(k) Have you ever been told that you had high
blood pressure?
Yes No
(l) Have you ever had a heart attack or heart
trouble?
Yes No
(3) Medical history update.
(a) Have you been in the hospital as a patient
any time within the past year?
Yes No
If so, for what condition?
(b) Have you been under the care of a physician
during the past year?
Yes No
If so, for what condition?
(c) Is there any change in your breathing since
last year?
Yes No
(i) Better?
(ii) Worse?
(iii) No change?
If change, do you know why?
(d) Is your general health different this year
from last year?
Yes No
If different, in what way?
(e) Have you in the past year or are you now taking
any medication on a regular basis?
Yes No
(i) Name Rx
(ii) Condition being treated
(4) Occupational history.
(a) How long have you worked for your present
employer?
(b) What jobs have you held with this employer?
Include job title and length of time in each job.
(c) In each of these jobs, how many hours a day
were you exposed to chemicals?
(d) What chemicals have you worked with most of
the time?
(e) Have you ever noticed any type of skin rash
you feel was related to your work?
Yes No
(f) Have you ever noticed that any kind of chemical
makes you cough?
Yes No
(i) Wheeze:
Yes No
(ii) Become short of breath or cause your chest
to become tight?
Yes No
(g) Are you exposed to any dust or chemicals at
home?
Yes No
If yes, explain:
(h) In other jobs, have you ever had exposure
to:
(i) Wood dust?
Yes No
(ii) Nickel or chromium?
Yes No
(iii) Silica (foundry, sand blasting)?
Yes No
(iv) Arsenic or asbestos?
Yes No
(v) Organic solvents?
Yes No
(vi) Urethane foams?
Yes No
(5) Occupational history update.
(a) Are you working on the same job this year
as you were last year?
Yes No
If not, how has your job changed?
(b) What chemicals are you exposed to on your
job?
(c) How many hours a day are you exposed to chemicals?
(d) Have you noticed any skin rash within the
past year you feel was related to your work?
Yes No
If so, explain circumstances:
(e) Have you noticed that any chemical makes you
cough, be short of breath, or wheeze?
Yes No
If so, can you identify it?
(6) Miscellaneous.
(a) Do you smoke?
Yes No
If so, how much and for how long?
(i) Pipe(ii)
Cigars
(iii) Cigarettes
(b) Do you drink alcohol in any form?
Yes No
If so, how much, how long, and how often?
(c) Do you wear glasses or contact lenses?
Yes No
(d) Do you get any physical exercise other than
that required to do your job?
Yes No
If so, explain:
(e) Do you have any hobbies or “side jobs”
that require you to use chemicals, such as furniture stripping,
sand blasting, insulation or manufacture of urethane foam, furniture,
etc.?
Yes No
If so, please describe, giving type of business
or hobby, chemicals used and length of exposures.
(7) Symptoms questionnaire.
(a) Do you ever have any shortness of breath?
Yes No
(i) If yes, do you have to rest after climbing
several flights of stairs?
Yes No
(ii) If yes, if you walk on the level with people
your own age, do you walk slower than they do?
Yes No
(iii) If yes, if you walk slower than a normal
pace, do you have to limit the distance that you walk?
Yes No
(iv) If yes, do you have to stop and rest while
bathing or dressing?
Yes No
(b) Do you cough as much as three months out of
the year?
Yes No
(i) If yes, have you had this cough for more
than two years?
Yes No
(ii) If yes, do you ever cough anything up from
the chest?
Yes No
(c) Do you ever have a feeling of smothering,
unable to take a deep breath, or tightness in your chest?
Yes No
(i) If yes, do you notice that this occurs on
any particular day of the week?
Yes No
(ii) If yes, what day of the week?
(iii) If yes, do you notice that this occurs
at any particular place?
Yes No
(iv) If yes, do you notice that this is worse
after you have returned to work after being off for several
days?
Yes No
(d) Have you ever noticed any wheezing in your
chest?
Yes No
(i) If yes, is this only with colds or other
infections?
Yes No
(ii) Is this caused by exposure to any kind
of dust or other material?
Yes No
(iii) If yes, what kind?
(e) Have you noticed any burning, tearing, or
redness of your eyes when you are at work?
Yes No
If so, explain circumstances:
(f) Have you noticed any sore or burning throat
or itchy or burning nose when you are at work?
Yes No
If so, explain circumstances:
(g) Have you noticed any stuffiness or dryness
of your nose?
Yes No
(h) Do you ever have swelling of the eyelids or
face?
Yes No
(i) Have you ever been jaundiced?
Yes No
If yes, was this accompanied by any pain?
Yes No
(j) Have you ever had a tendency to bruise easily
or bleed excessively?
Yes No
(k) Do you have frequent headaches that are not
relieved by aspirin or tylenol?
Yes No
(i) If yes, do they occur at any particular
time of the day or week?
Yes No
(ii) If yes, when do they occur?
(l) Do you have frequent episodes of nervousness
or irritability?
Yes No
(m) Do you tend to have trouble concentrating
or remembering?
Yes No
(n) Do you ever feel dizzy, light-headed, excessively
drowsy, or like you have been drugged?
Yes No
(o) Does your vision ever become blurred?
Yes No
(p) Do you have numbness or tingling of the hands
or feet or other parts of your body?
Yes No
(q) Have you ever had chronic weakness or fatigue?
Yes No
(r) Have you every had any swelling of your feet
or ankles to the point where you could not wear your shoes?
Yes No
(s) Are you bothered by heartburn or indigestion?
Yes No
(t) Do you ever have itching, dryness, or peeling
and scaling of the hands?
Yes No
(u) Do you ever have a burning sensation in the
hands, or reddening of the skin?
Yes No
(v) Do you ever have cracking or bleeding of the
skin on your hands?
Yes No
(w) Are you under a physician's care?
Yes No
If yes, for what are you being treated?
(x) Do you have any physical complaints today?
Yes No
If yes, explain:
(y) Do you have other health conditions not covered
by these questions?
(1) WAC
296-62-076 applies to all occupational exposures to MDA, Chemical
Abstracts Service Registry No. 101-77-9, except as provided in
subsections (2) through (7) of this section.
(2) Except as provided in subsection (8) of this
section and WAC
296-62-07609(5), this section does not apply to the processing,
use, and handling of products containing MDA where initial monitoring
indicates that the product is not capable of releasing MDA in
excess of the action level under the expected conditions of processing,
use, and handling which will cause the greatest possible release;
and where no “dermal exposure to MDA” can occur.
(3) Except as provided in subsection (8) of this
section, WAC
296-62-076 does not apply to the processing, use, and handling
of products containing MDA where objective data are reasonably
relied upon which demonstrate the product is not capable of releasing
MDA under the expected conditions of processing, use, and handling
which will cause the greatest possible release; and where no “dermal
exposure to MDA” can occur.
(4) WAC
296-62-076 does not apply to the storage, transportation,
distribution, or sale of MDA in intact containers sealed in such
a manner as to contain the MDA dusts, vapors, or liquids, except
for the provisions of WAC 296-62-054, 296-62-07607
and 296-800-170.
(6) Except as provided in subsection (8) of this
section, WAC
296-62-076 does not apply to materials in any form which contain
less than 0.1% MDA by weight or volume.
(7) Except as provided in subsection (8) of this
section, WAC
296-62-076 does not apply to “finished articles containing
MDA.”
(8) Where products containing MDA are exempted under
subsections (2) through (7) of this section, the employer shall
maintain records of the initial monitoring results or objective
data supporting that exemption and the basis for the employer's
reliance on the data, as provided in the recordkeeping provision
of WAC
296-62-07631.
For the purpose of WAC
296-62-076, the following definitions shall apply:
(1) “Action level” means a concentration
of airborne MDA of 5 ppb as an 8-hour time-weighted average.
(2) “Authorized person” means
any person specifically authorized by the employer whose duties
require the person to enter a regulated area, or any person entering
such an area as a designated representative of employees, for
the purpose of exercising the right to observe monitoring and
measuring procedures under WAC
296-62-07633 of WAC
296-62-076, or any other person authorized by WISHA or regulations
issued by WISHA.
(3) “Container” means any barrel,
bottle, can, cylinder, drum, reaction vessel, storage tank, commercial
packaging, or the like, but does not include piping systems.
(4) “Dermal exposure to MDA”
occurs where employees are engaged in the handling, application,
or use of mixtures or materials containing MDA, with any of the
following nonairborne forms of MDA:
(a) Liquid, powdered, granular, or flaked mixtures
containing MDA in concentrations greater than 0.1% by weight
or volume; and
(b) Materials other than “finished articles”
containing MDA in concentrations greater than 0.1% by weight
or volume.
(5) “Director” means the director
of the department of labor and industries, or his/her designated
representative.
(6) “Emergency” means any occurrence
such as, but not limited to, equipment failure, rupture of containers,
or failure of control equipment which results in an unexpected
and potentially hazardous release of MDA.
(7) “Employee exposure” means
exposure to MDA which would occur if the employee were not using
respirators or protective work clothing and equipment.
(8) “Finished article containing MDA”
is defined as a manufactured item:
(a) Which is formed to a specific shape or design
during manufacture;
(b) Which has end use function(s) dependent in
whole or part upon its shape or design during end use; and
(c) Where applicable, is an item which is fully
cured by virtue of having been subjected to the conditions (temperature,
time) necessary to complete the desired chemical reaction.
(9) “4,4' methylenedianiline”
or “MDA” means the chemical 4,4'- diaminodiphenylmethane,
Chemical Abstract Service Registry number 101-77-9, in the form
of a vapor, liquid, or solid. The definition also includes the
salts of MDA.
(10) “Regulated areas” means
areas where airborne concentrations of MDA exceed or can reasonably
be expected to exceed, the permissible exposure limits, or where
dermal exposure to MDA can occur.
(11) “STEL” means short-term
exposure limit as determined by any 15 minute sample period.
The employer shall assure that no employee is exposed
to an airborne concentration of MDA in excess of ten parts per
billion (10 ppb) as an 8-hour time-weighted average or a STEL
of 100 ppb.
(a) A written plan for emergency situations shall
be developed for each workplace where there is a possibility
of an emergency. Appropriate portions of the plan shall be implemented
in the event of an emergency.
(b) The plan shall specifically provide that employees
engaged in correcting emergency conditions shall be equipped
with the appropriate personal protective equipment and clothing
as required in WAC
296-62-07615 and 296-62-07617
until the emergency is abated.
(c) The plan shall specifically include provisions
for alerting and evacuating affected employees as well as the
elements prescribed in chapter
296-24 WAC, Part G-1, “Employee emergency plans and
fire prevention plans.”
(2) Alerting employees. Where there is the possibility
of employee exposure to MDA due to an emergency, means shall be
developed to alert promptly those employees who have the potential
to be directly exposed. Affected employees not engaged in correcting
emergency conditions shall be evacuated immediately in the event
that an emergency occurs. Means shall also be developed and implemented
for alerting other employees who may be exposed as a result of
the emergency.
(a) Determinations of employee exposure shall
be made from breathing zone air samples that are representative
of each employee's exposure to airborne MDA over an 8-hour period.
Determination of employee exposure to the STEL shall be made
from breathing zone air samples collected over a 15 minute sampling
period.
(b) Representative employee exposure shall be
determined on the basis of one or more samples representing
full shift exposure for each shift for each job classification
in each work area where exposure to MDA may occur.
(c) Where the employer can document that exposure
levels are equivalent for similar operations in different work
shifts, the employer shall only be required to determine representative
employee exposure for that operation during one shift.
(2) Initial monitoring. Each employer who has a
workplace or work operation covered by this standard shall perform
initial monitoring to determine accurately the airborne concentrations
of MDA to which employees may be exposed.
(3) Periodic monitoring and monitoring frequency.
(a) If the monitoring required by subsection (2)
of this section reveals employee exposure at or above the action
level, but at or below the PELs, the employer shall repeat such
representative monitoring for each such employee at least every
six months.
(b) If the monitoring required by subsection (2)
of this section reveals employee exposure above the PELs, the
employer shall repeat such monitoring for each such employee
at least every three months.
(c) The employer may alter the monitoring schedule
from every three months to every six months for any employee
for whom two consecutive measurements taken at least 7 days
apart indicate that the employee exposure has decreased to below
the TWA but above the action level.
(4) Termination of monitoring.
(a) If the initial monitoring required by subsection
(2) of this section reveals employee exposure to be below the
action level, the employer may discontinue the monitoring for
that employee, except as otherwise required by subsection (5)
of this section.
(b) If the periodic monitoring required by subsection
(3) of this section reveals that employee exposures, as indicated
by at least two consecutive measurements taken at least 7 days
apart, are below the action level the employer may discontinue
the monitoring for that employee, except as otherwise required
by subsection (5) of this section.
(5) Additional monitoring. The employer shall institute
the exposure monitoring required under subsections (2) and (3)
of this section when there has been a change in production process,
chemicals present, control equipment, personnel, or work practices
which may result in new or additional exposures to MDA, or when
the employer has any reason to suspect a change which may result
in new or additional exposures.
(6) Accuracy of monitoring. Monitoring shall be
accurate, to a confidence level of 95 percent, to within plus
or minus 25 percent for airborne concentrations of MDA.
(7) Employee notification of monitoring results.
(a) The employer shall, within 15 working days
after the receipt of the results of any monitoring performed
under this standard, notify each employee of these results,
in writing, either individually or by posting of results in
an appropriate location that is accessible to affected employees.
(b) The written notification required by subdivision
(a) of this subsection shall contain the corrective action being
taken by the employer to reduce the employee exposure to or
below the PELs, wherever the PELs are exceeded.
(8) Visual monitoring. The employer shall make routine
inspections of employee hands, face, and forearms potentially
exposed to MDA. Other potential dermal exposures reported by the
employee must be referred to the appropriate medical personnel
for observation. If the employer determines that the employee
has been exposed to MDA the employer shall:
(a) Determine the source of exposure;
(b) Implement protective measures to correct the
hazard; and
(c) Maintain records of the corrective actions
in accordance with WAC
296-62-07631.
(a) Airborne exposures. The employer shall establish
regulated areas where airborne concentrations of MDA exceed
or can reasonably be expected to exceed, the permissible exposure
limits.
(b) Dermal exposures. Where employees are subject
to dermal exposure to MDA the employer shall establish those
work areas as regulated areas.
(2) Demarcation. Regulated areas shall be demarcated
from the rest of the workplace in a manner that minimizes the
number of persons potentially exposed.
(3) Access. Access to regulated areas shall be limited
to authorized persons.
(4) Personal protective equipment and clothing.
Each person entering a regulated area shall be supplied with,
and required to use, the appropriate personal protective clothing
and equipment in accordance with WAC
296-62-07615 and 296-62-07617.
(5) Prohibited activities. The employer shall ensure
that employees do not eat, drink, smoke, chew tobacco or gum,
or apply cosmetics in regulated areas.
(a) The employer shall institute engineering controls
and work practices to reduce and maintain employee exposure
to MDA at or below the PELs except to the extent that the employer
can establish that these controls are not feasible or where
the provisions of subdivision (b) of this subsection or WAC
296-62-07615(1) apply.
(b) Wherever the feasible engineering controls
and work practices which can be instituted are not sufficient
to reduce employee exposure to or below the PELs, the employer
shall use them to reduce employee exposure to the lowest levels
achievable by these controls and shall supplement them by the
use of respiratory protective devices which comply with the
requirements of WAC
296-62-07615.
(2) Compliance program.
(a) The employer shall establish and implement
a written program to reduce employee exposure to or below the
PELs by means of engineering and work practice controls, as
required by subsection (1) of this section, and by use of respiratory
protection where permitted under WAC
296-62-076. The program shall include a schedule for periodic
maintenance (e.g., leak detection) and shall include the written
plan for emergency situations as specified in WAC
296-62-07607.
(b) Upon request this written program shall be
furnished for examination and copying to the director, affected
employees, and designated employee representatives. The employer
shall review and, as necessary, update such plans at least once
every 12 months to make certain they reflect the current status
of the program.
(3) Employee rotation. Employee rotation shall not
be permitted as a means of reducing exposure.
(1) General. For employees who use respirators required
by this section, the employer must provide respirators that comply
with the requirements of this subsection. Respirators must be
used during:
(a) Periods necessary to install or implement
feasible engineering and work-practice controls;
(b) Work operations for which the employer establishes
that engineering and work-practice controls are not feasible;
(c) Work operations for which feasible engineering
and work-practice controls are not yet sufficient to reduce
exposure to or below the PEL;
(d) Emergencies.
(2) Respirator program. The employer must develop,
implement and maintain a respiratory protection program as required
by chapter
296-842 WAC, Respirators.
(3) Respirator selection.
(a) The employer must select and provide to employees
appropriate respirators as specified in this section and WAC
296-842-13005 in the respirator rule.
(b) Any employee who cannot use a negative-pressure
respirator must be given the option of using a positive-pressure
respirator, or a supplied-air respirator operated in the continuous-flow
or pressure-demand mode.
(c) Provide HEPA filters or N-, R-, or P-100 filters
for powered air-purifying respirators (PAPRs) and negative-pressure
air-purifying respirators.
(d) Provide to employees, for escape, one of the
following respirator options:
(i) Any self-contained breathing apparatus with
a full-facepiece or hood, operated in the positive-pressure
or continuous-flow mode.
OR
(ii) A full-facepiece air-purifying respirator.
(e) Provide a combination HEPA filter (or N-,
R-, P-100 filter) and organic vapor canister or cartridge with
air-purifying respirators when MDA is in liquid form or used
as part of a process requiring heat.
(1) Provision and use. Where employees are subject
to dermal exposure to MDA, where liquids containing MDA can
be splashed into the eyes, or where airborne concentrations
of MDA are in excess of the PEL, the employer shall provide,
at no cost to the employee, and ensure that the employee uses,
appropriate protective work clothing and equipment which prevent
contact with MDA such as, but not limited to:
(a) Aprons, coveralls, or other full-body work
clothing;
(b) Gloves, head coverings, and foot coverings;
and
(c) Face shields, chemical goggles; or
(d) Other appropriate protective equipment which
comply with WAC
296-800-160.
(2) Removal and storage.
(a) The employer shall ensure that, at the end
of their work shift, employees remove MDA-contaminated protective
work clothing and equipment that is not routinely removed
throughout the day in change rooms provided in accordance
with the provisions established for change rooms.
(b) The employer shall ensure that, during their
work shift, employees remove all other MDA-contaminated protective
work clothing or equipment before leaving a regulated area.
(c) The employer shall ensure that no employee
takes MDA-contaminated work clothing or equipment out of the
change room, except those employees authorized to do so for
the purpose of laundering, maintenance, or disposal.
(d) MDA-contaminated work clothing or equipment
shall be placed and stored in closed containers which prevent
dispersion of the MDA outside the container.
(e) Containers of MDA-contaminated protective
work clothing or equipment which are to be taken out of change
rooms or the workplace for cleaning, maintenance, or disposal
shall bear labels warning of the hazards of MDA.
(3) Cleaning and replacement.
(a) The employer shall provide the employee
with clean protective clothing and equipment. The employer
shall ensure that protective work clothing or equipment required
by this paragraph is cleaned, laundered, repaired, or replaced
at intervals appropriate to maintain its effectiveness.
(b) The employer shall prohibit the removal
of MDA from protective work clothing or equipment by blowing,
shaking, or any methods which allow MDA to reenter the workplace.
(c) The employer shall ensure that laundering
of MDA-contaminated clothing shall be done so as to prevent
the release of MDA in the workplace.
(d) Any employer who gives MDA-contaminated
clothing to another person for laundering shall inform such
person of the requirement to prevent the release of MDA.
(e) The employer shall inform any person who
launders or cleans protective clothing or equipment contaminated
with MDA of the potentially harmful effects of exposure.
(f) MDA-contaminated clothing shall be transported
in properly labeled, sealed, impermeable bags or containers.
(a) The employer shall provide clean change
rooms for employees, who must wear protective clothing, or
who must use protective equipment because of their exposure
to MDA.
(b) Change rooms must be equipped with separate
storage for protective clothing and equipment and for street
clothes which prevents MDA contamination of street clothes.
(2) Showers.
(a) The employer shall ensure that employees,
who work in areas where there is the potential for exposure
resulting from airborne MDA (e.g., particulates or vapors)
above the action level, shower at the end of the work shift.
(i) Shower facilities required by this section
shall comply with WAC 296-24-12010.
(ii) The employer shall ensure that employees
who are required to shower pursuant to the provisions contained
herein do not leave the workplace wearing any protective
clothing or equipment worn during the work shift.
(b) Where dermal exposure to MDA occurs, the
employer shall ensure that materials spilled or deposited
on the skin are removed as soon as possible by methods which
do not facilitate the dermal absorption of MDA.
(3) Lunch facilities.
(a) Availability and construction.
(i) Whenever food or beverages are consumed
at the worksite and employees are exposed to MDA at or above
the PEL or are subject to dermal exposure to MDA the employer
shall provide readily accessible lunch areas.
(ii) Lunch areas located within the workplace
and in areas where there is the potential for airborne exposure
to MDA at or above the PEL shall have a positive pressure,
temperature controlled, filtered air supply.
(iii) Lunch areas may not be located in areas
within the workplace where the potential for dermal exposure
to MDA exists.
(b) The employer shall ensure that employees
who have been subjected to dermal exposure to MDA or who have
been exposed to MDA above the PEL wash their hands and faces
with soap and water prior to eating, drinking, smoking, or
applying cosmetics.
(c) The employer shall ensure that employees
exposed to MDA do not enter lunch facilities with MDA-contaminated
protective work clothing or equipment.
(a) The employer shall post and maintain legible
signs demarcating regulated areas and entrances or accessways
to regulated areas that bear the following legend:
DANGER MDA MAY CAUSE CANCER LIVER TOXIN
AUTHORIZED PERSONNEL ONLY RESPIRATORS AND
PROTECTIVE CLOTHING
MAY BE REQUIRED TO BE WORN IN THIS AREA
(b) The employer shall ensure that labels or
other appropriate forms of warning are provided for containers
of MDA within the workplace. The labels shall comply with
the requirements of chapter
296-839 WAC, Content and distribution of material safety
data sheets (MSDSs) and label information and WAC
296-800-170 of the safety and health core rules, and the
labels shall include the following legend:
(i) For pure MDA
DANGER CONTAINS MDA MAY CAUSE CANCER LIVER
TOXIN
(ii) For mixtures containing MDA
DANGER CONTAINS MDA CONTAINS MATERIALS
WHICH MAY CAUSE CANCER LIVER TOXIN
(2) Material safety data sheets (MSDS).
(a) Employers shall obtain or develop, and shall
provide access to their employees, to a material safety data
sheet (MSDS) for MDA. In meeting this obligation, employers
shall make appropriate use of the information found in Appendices
A and B.
(b) Employers who are manufacturers or importers
shall:
(i) Comply with subdivision (1)(b) of this
section as appropriate; and
(ii) Comply with the requirement in WISHA
hazard communication standard, chapter
296-839 WAC, that they deliver to downstream employers
an MSDS for MDA.
(3) Information and training.
(a) The employer shall provide employees with
information and training on MDA, in accordance with WAC
296-800-170, at the time of initial assignment and at
least annually thereafter.
(b) In addition to the information required
under WAC
296-800-170, the employer shall:
(i) Provide an explanation of the contents
of WAC
296-62-076, including Appendices A and B, and indicate
to employees where a copy of the standard is available;
(ii) Describe the medical surveillance program
required under WAC
296-62-07625, and explain the information contained
in Appendix C; and
(iii) Describe the medical removal provision
required under WAC
296-62-07625.
(4) Access to training materials.
(a) The employer shall make readily available
to all affected employees, without cost, all written materials
relating to the employee training program, including a copy
of this regulation.
(b) The employer shall provide to the director,
upon request, all information and training materials relating
to the employee information and training program.
(1) All surfaces shall be maintained as free as
practicable of visible accumulations of MDA.
(2) The employer shall institute a program for
detecting MDA leaks, spills, and discharges, including regular
visual inspections of operations involving liquid or solid MDA.
(3) All leaks shall be repaired and liquid or
dust spills cleaned up promptly.
(4) Surfaces contaminated with MDA may not be
cleared by the use of compressed air.
(5) Shoveling, dry sweeping, and other methods
of dry clean-up of MDA may be used where HEPA-filtered vacuuming
and/or wet cleaning are not feasible or practical.
(6) Waste, scrap, debris, bags, containers, equipment,
and clothing contaminated with MDA shall be collected and disposed
of in a manner to prevent the reentry of MDA into the workplace.
(a) The employer shall make available a medical
surveillance program for employees exposed to MDA:
(i) Employees exposed at or above the action
level for 30 or more days per year;
(ii) Employees who are subject to dermal exposure
to MDA for 15 or more days per year;
(iii) Employees who have been exposed in an
emergency situation;
(iv) Employees whom the employer, based on
results from compliance with WAC
296-62-07609(8), has reason to believe are being dermally
exposed; and
(v) Employees who show signs or symptoms of
MDA exposure.
(b) The employer shall ensure that all medical
examinations and procedures are performed by, or under the
supervision of, a licensed physician, at a reasonable time
and place, and provided without cost to the employee.
(2) Initial examinations.
(a) Within 150 days of the effective date of
this standard, or before the time of initial assignment, the
employer shall provide each employee covered by subdivision
(1)(a) of this section with a medical examination including
the following elements:
(i) A detailed history which includes:
(A) Past work exposure to MDA or any other
toxic substances;
(B) A history of drugs, alcohol, tobacco,
and medication routinely taken (duration and quantity);
and
(C) A history of dermatitis, chemical skin
sensitization, or previous hepatic disease.
(ii) A physical examination which includes
all routine physical examination parameters, skin examination,
and signs of liver disease.
(iii) Laboratory tests including:
(A) Liver function tests; and
(B) Urinalysis.
(iv) Additional tests as necessary in the
opinion of the physician.
(b) No initial medical examination is required
if adequate records show that the employee has been examined
in accordance with the requirements of WAC
296-62-076 within the previous six months prior to the
effective date of this standard or prior to the date of initial
assignment.
(3) Periodic examinations.
(a) The employer shall provide each employee
covered by WAC
296-62-076 with a medical examination at least annually
following the initial examination. These periodic examinations
shall include at least the following elements:
(i) A brief history regarding any new exposure
to potential liver toxins, changes in drug, tobacco, and
alcohol intake, and the appearance of physical signs relating
to the liver and the skin;
(ii) The appropriate tests and examinations
including liver function tests and skin examinations; and
(iii) Appropriate additional tests or examinations
as deemed necessary by the physician.
(b) If in the physicians' opinion the results
of liver function tests indicate an abnormality, the employee
shall be removed from further MDA exposure in accordance with
WAC
296-62-07627 and 296-62-07629.
Repeat liver function tests shall be conducted on advice of
the physician.
(4) Emergency examinations. If the employer determines
that the employee has been exposed to a potentially hazardous
amount of MDA in an emergency situation as addressed in WAC
296-62-07607, the employer shall provide medical examinations
in accordance with subsection (3) of this section. If the results
of liver function testing indicate an abnormality, the employee
shall be removed in accordance with WAC
296-62-07627 and 296-62-07629.
Repeat liver function tests shall be conducted on the advice
of the physician. If the results of the tests are normal, tests
must be repeated two to three weeks from the initial testing.
If the results of the second set of tests are normal and on
the advice of the physician, no additional testing is required.
(5) Additional examinations. Where the employee
develops signs and symptoms associated with exposure to MDA,
the employer shall provide the employee with an additional medical
examination including a liver function test. Repeat liver function
tests shall be conducted on the advice of the physician. If
the results of the tests are normal, tests must be repeated
two to three weeks from the initial testing. If the results
of the second set of tests are normal and, on the advice of
the physician, no additional testing is required.
(6) Multiple physician review mechanism.
(a) If the employer selects the initial physician
who conducts any medical examination or consultation provided
to an employee under WAC
296-62-076, and the employee has signs or symptoms of
occupational exposure to MDA (which could include an abnormal
liver function test), and the employee disagrees with the
opinion of the examining physician, and this opinion could
affect the employee's job status, the employee may designate
an appropriate, mutually acceptable second physician:
(i) To review any findings, determinations,
or recommendations of the initial physician; and
(ii) To conduct such examinations, consultations,
and laboratory tests as the second physician deems necessary
to facilitate this review.
(b) The employer shall promptly notify an employee
of the right to seek a second medical opinion after each occasion
that an initial physician conducts a medical examination or
consultation pursuant to WAC
296-62-076. The employer may condition its participation
in, and payment for, the multiple physician review mechanism
upon the employee doing the following within fifteen days
after receipt of the foregoing notification, or receipt of
the initial physician's written opinion, whichever is later:
(i) The employee informing the employer that
he or she intends to seek a second medical opinion; and
(ii) The employee initiating steps to make
an appointment with a second physician.
(c) If the findings, determinations, or recommendations
of the second physician differ from those of the initial physician,
then the employer and the employee shall assure that efforts
are made for the two physicians to resolve any disagreement.
(d) If the two physicians have been unable to
resolve quickly their disagreement, then the employer and
the employee through their respective physicians shall designate
a third physician:
(i) To review any findings, determinations,
or recommendations of the prior physicians; and
(ii) To conduct such examinations, consultations,
laboratory tests, and discussions with the prior physicians
as the third physician deems necessary to resolve the disagreement
of the prior physicians.
(e) The employer shall act consistent with the
findings, determinations, and recommendations of the third
physician, unless the employer and the employee reach an agreement
which is otherwise consistent with the recommendations of
at least one of the three physicians.
(7) Information provided to the examining and
consulting physicians.
(a) The employer shall provide the following
information to the examining physician:
(i) A copy of this regulation and its appendices;
(ii) A description of the affected employee's
duties as they relate to the employee's potential exposure
to MDA;
(iii) The employee's current actual or representative
MDA exposure level;
(iv) A description of any personal protective
equipment used or to be used; and
(v) Information from previous employment-related
medical examinations of the affected employee.
(b) The employer shall provide the foregoing
information to a second physician under this section upon
request either by the second physician or by the employee.
(8) Physician's written opinion.
(a) For each examination under WAC
296-62-076, the employer shall obtain, and provide the
employee with a copy of, the examining physician's written
opinion within 15 days of its receipt. The written opinion
shall include the following:
(i) The occupationally-pertinent results of
the medical examination and tests;
(ii) The physician's opinion concerning whether
the employee has any detected medical conditions which would
place the employee at increased risk of material impairment
of health from exposure to MDA;
(iii) The physician's recommended limitations
upon the employee's exposure to MDA or upon the employee's
use of protective clothing or equipment and respirators;
and
(iv) A statement that the employee has been
informed by the physician of the results of the medical
examination and any medical conditions resulting from MDA
exposure which require further explanation or treatment.
(b) The written opinion obtained by the employer
shall not reveal specific findings or diagnoses unrelated
to occupational exposures.
WAC
296-62-07627 Medical removal--Temporary medical removal
of an employee. Temporary medical removal of an employee.
(1) Temporary removal resulting from occupational
exposure. The employee shall be removed from work environments
in which exposure to MDA is at or above the action level or
where dermal exposure to MDA may occur, following an initial
examination (WAC
296-62-07625(2)), periodic examinations (WAC
296-62-07625(3)), an emergency situation (WAC
296-62-07625(4)), or an additional examination (WAC
296-62-07625(5)) in the following circumstances:
(a) When the employee exhibits signs and/or
symptoms indicative of acute exposure to MDA; or
(b) When the examining physician determines
that an employee's abnormal liver function tests are not associated
with MDA exposure but that the abnormalities may be exacerbated
as a result of occupational exposure to MDA.
(c) Temporary removal due to a final medical
determination.
(i) The employer shall remove an employee
from work environments in which exposure to MDA is at or
above the action level or where dermal exposure to MDA may
occur, on each occasion that there is a final medical determination
or opinion that the employee has a detected medical condition
which places the employee at increased risk of material
impairment to health from exposure to MDA.
(ii) For the purposes of WAC
296-62-076, the phrase “final medical determination”
shall mean the outcome of the physician review mechanism
used pursuant to the medical surveillance provisions of
this section.
(iii) Where a final medical determination
results in any recommended special protective measures for
an employee, or limitations on an employee's exposure to
MDA, the employer shall implement and act consistent with
the recommendation.
(2) Return of the employee to former job status.
(a) The employer shall return an employee to
his or her former job status:
(i) When the employee no longer shows signs
or symptoms of exposure to MDA or upon the advice of the
physician.
(ii) When a subsequent final medical determination
results in a medical finding, determination, or opinion
that the employee no longer has a detected medical condition
which places the employee at increased risk of material
impairment to health from exposure to MDA.
(b) For the purposes of this section, the requirement
that an employer return an employee to his or her former job
status is not intended to expand upon or restrict any rights
an employee has or would have had, absent temporary medical
removal, to a specific job classification or position under
the terms of a collective bargaining agreement.
(3) Removal of other employee special protective
measure or limitations. The employer shall remove any limitations
placed on an employee, or end any special protective measures
provided to an employee, pursuant to a final medical determination,
when a subsequent final medical determination indicates that
the limitations or special protective measures are no longer
necessary.
(4) Employer options pending a final medical determination.
Where the physician review mechanism used pursuant to the medical
surveillance provisions of WAC
296-62-076, has not yet resulted in a final medical determination
with respect to an employee, the employer shall act as follows:
(a) Removal. The employer may remove the employee
from exposure to MDA, provide special protective measures
to the employee, or place limitations upon the employee, consistent
with the medical findings, determinations, or recommendations
of any of the physicians who have reviewed the employee's
health status.
(b) Return. The employer may return the employee
to his or her former job status, and end any special protective
measures provided to the employee, consistent with the medical
findings, determinations, or recommendations of any of the
physicians who have reviewed the employee's health status,
with two exceptions.
(i) If the initial removal, special protection,
or limitation of the employee resulted from a final medical
determination which differed from the findings, determinations,
or recommendations of the initial physician; or
(ii) If the employee has been on removal status
for the preceding six months as a result of exposure to
MDA, then the employer shall await a final medical determination.
(1) Provisions of medical removal protection benefits.
The employer shall provide to an employee up to six months of
medical removal protection benefits on each occasion that an
employee is removed from exposure to MDA or otherwise limited
pursuant to this section.
(2) Definition of medical removal protection benefits.
For the purposes of this section, the requirement that an employer
provide medical removal protection benefits means that the employer
shall maintain the earnings, seniority, and other employment
rights and benefits of an employee as though the employee had
not been removed from normal exposure to MDA or otherwise limited.
(3) Follow-up medical surveillance during the
period of employee removal or limitations. During the period
of time that an employee is removed from normal exposure to
MDA or otherwise limited, the employer may condition the provision
of medical removal protection benefits upon the employee's participation
in follow-up medical surveillance made available pursuant to
WAC
296-62-076.
(4) Workers' compensation claims. If a removed
employee files a claim for workers' compensation payments for
an MDA-related disability, then the employer shall continue
to provide medical removal protection benefits pending disposition
of the claim. To the extent that an award is made to the employee
for earnings lost during the period of removal, the employer's
medical removal protection obligation shall be reduced by such
amount. The employer shall receive no credit for workers' compensation
payments received by the employee for treatment-related expenses.
(5) Other credits. The employer's obligation to
provide medical removal protection benefits to a removed employee
shall be reduced to the extent that the employee receives compensation
for earnings lost during the period of removal either from a
publicly or employer-funded compensation program, or receives
income from non-MDA-related employment with any employer made
possible by virtue of the employee's removal.
(6) Employees who do not recover within the 6
months of removal. The employer shall take the following measures
with respect to any employee removed from exposure to MDA:
(a) The employer shall make available to the
employee a medical examination pursuant to this section to
obtain a final medical determination with respect to the employee;
(b) The employer shall assure that the final
medical determination obtained indicates whether or not the
employee may be returned to his or her former job status,
and, if not, what steps should be taken to protect the employee's
health;
(c) Where the final medical determination has
not yet been obtained, or, once obtained indicates that the
employee may not yet be returned to his or her former job
status, the employer shall continue to provide medical removal
protection benefits to the employee until either the employee
is returned to former job status, or a final medical determination
is made that the employee is incapable of ever safely returning
to his or her former job status; and
(d) Where the employer acts pursuant to a final
medical determination which permits the return of the employee
to his or her former job status, despite what would otherwise
be an abnormal liver function test, later questions concerning
removing the employee again shall be decided by a final medical
determination. The employer need not automatically remove
such an employee pursuant to the MDA removal criteria provided
by WAC
296-62-076.
(7) Voluntary removal or restriction of an employee.
Where an employer, although not required by WAC
296-62-076 to do so, removes an employee from exposure to
MDA or otherwise places limitations on an employee due to the
effects of MDA exposure on the employee's medical condition,
the employer shall provide medical removal protection benefits
to the employee equal to that required by this section.
(a) Where as a result of the initial monitoring
the processing, use, or handling of products made from or
containing MDA are exempted from other requirements of this
section under WAC
296-62-07601(2), the employer shall establish and maintain
an accurate record of monitoring relied on in support of the
exemption.
(b) This record shall include at least the following
information:
(i) The product qualifying for exemption;
(ii) The source of the monitoring data (e.g.,
was monitoring performed by the employer or a private contractor);
(iii) The testing protocol, results of testing,
and/or analysis of the material for the release of MDA;
(iv) A description of the operation exempted
and how the data support the exemption (e.g., are the monitoring
data representative of the conditions at the affected facility);
and
(v) Other data relevant to the operations,
materials, processing, or employee exposures covered by
the exemption.
(c) The employer shall maintain this record
for the duration of the employer's reliance upon such objective
data.
(2) Objective data for exempted employers.
(a) Where the processing, use, or handling of
products made from or containing MDA are exempted from other
requirements of WAC
296-62-076 under WAC
296-62-07601, the employer shall establish and maintain
an accurate record of objective data relied upon in support
of the exemption.
(b) This record shall include at least the following
information:
(i) The product qualifying for exemption;
(ii) The source of the objective data;
(iii) The testing protocol, results of testing,
and/or analysis of the material for the release of MDA;
(iv) A description of the operation exempted
and how the data support the exemption; and
(v) Other data relevant to the operations,
materials, processing, or employee exposures covered by
the exemption.
(c) The employer shall maintain this record
for the duration of the employer's reliance upon such objective
data.
(3) Exposure measurements.
(a) The employer shall establish and maintain
an accurate record of all measurements required by WAC
296-62-07609, in accordance with Part B of this chapter.
(b) This record shall include:
(i) The dates, number, duration, and results
of each of the samples taken, including a description of
the procedure used to determine representative employee
exposures;
(ii) Identification of the sampling and analytical
methods used;
(iii) A description of the type of respiratory
protective devices worn, if any; and
(iv) The name, Social Security number, job
classification, and exposure levels of the employee monitored
and all other employees whose exposure the measurement is
intended to represent.
(c) The employer shall maintain this record
for at least 30 years, in accordance with Part B of this chapter.
(4) Medical surveillance.
(a) The employer shall establish and maintain
an accurate record for each employee subject to medical surveillance
required by WAC
296-62-07625, 296-62-07627,
and 296-62-07629,
in accordance with Part B of this chapter.
(b) This record shall include:
(i) The name, Social Security number, and
description of the duties of the employee;
(ii) The employer's copy of the physician's
written opinion on the initial, periodic, and any special
examinations, including results of medical examination and
all tests, opinions, and recommendations;
(iii) Results of any airborne exposure monitoring
done for that employee and the representative exposure levels
supplied to the physician; and
(iv) Any employee medical complaints related
to exposure to MDA.
(c) The employer shall keep, or assure that
the examining physician keeps, the following medical records:
(i) A copy of this standard and its appendices,
except that the employer may keep one copy of the standard
and its appendices for all employees provided the employer
references the standard and its appendices in the medical
surveillance record of each employee;
(ii) A copy of the information provided to
the physician as required by any sections in the regulatory
text;
(iii) A description of the laboratory procedures
and a copy of any standards or guidelines used to interpret
the test results or references to the information;
(iv) A copy of the employee's medical and
work history related to exposure to MDA.
(d) The employer shall maintain this record
for at least the duration of employment plus 30 years, in
accordance with Part B of this chapter.
(5) Medical removals.
(a) The employer shall establish and maintain
an accurate record for each employee removed from current
exposure to MDA pursuant to WAC
296-62-07625, 296-62-07627,
and 296-62-07629.
(b) Each record shall include:
(i) The name and Social Security number of
the employee;
(ii) The date of each occasion that the employee
was removed from current exposure to MDA as well as the
corresponding date on which the employee was returned to
his or her former job status;
(iii) A brief explanation of how each removal
was or is being accomplished; and
(iv) A statement with respect to each removal
indicating the reason for the removal.
(c) The employer shall maintain each medical
removal record for at least the duration of an employee's
employment plus 30 years.
(6) Availability.
(a) The employer shall assure that records required
to be maintained by WAC
296-62-076 shall be made available, upon request, to the
director for examination and copying.
(b) Employee exposure monitoring records required
by WAC
296-62-076 shall be provided upon request for examination
and copying to employees, employee representatives, and the
director in accordance with the applicable sections of WAC
296-800-170.
(c) Employee medical records required by this
section shall be provided upon request for examination and
copying, to the subject employee, to anyone having the specific
written consent of the subject employee, and to the director
in accordance with Part B of this chapter.
(7) Transfer of records.
(a) The employer shall comply with the requirements
involving transfer of records set forth in chapter 296-802
WAC.
(b) If the employer ceases to do business and
there is no successor employer to receive and retain the records
for the prescribed period, the employer shall notify the director,
at least 90 days prior to disposal, and transmit the records
to the director if so requested by the director within that
period.
(1) Employee observation. The employer shall provide
affected employees, or their designated representatives, an
opportunity to observe the measuring or monitoring of employee
exposure to MDA conducted pursuant to WAC
296-62-07609.
(2) Observation procedures. When observation of
the measuring or monitoring of employee exposure to MDA requires
entry into areas where the use of protective clothing and equipment
or respirators is required, the employer shall provide the observer
with personal protective clothing and equipment or respirators
required to be worn by employees working in the area, assure
the use of such clothing and equipment or respirators, and require
the observer to comply with all other applicable safety and
health procedures.
The information contained in Appendices A, B,
C, and D of WAC
296-62-076 is not intended by itself, to create any additional
obligations not otherwise imposed by this standard nor detract
from any existing obligation. The protocols for respiratory
fit testing in Appendix E of WAC
296-62-076 are mandatory.
(i) Airborne: Ten parts per billion parts
of air (10 ppb), time-weighted average (TWA) for an 8-hour
workday and an action level of five parts per billion parts
of air (5 ppb).
(ii) Dermal: Eye contact and skin contact
with MDA are not permitted.
(c) Appearance and odor: White to tan solid;
amine odor.
(2) Health hazard data.
(a) Ways in which MDA affects your health. MDA
can affect your health if you inhale it, or if it comes in
contact with your skin or eyes. MDA is also harmful if you
happen to swallow it. Do not get MDA in eyes, on skin, or
on clothing.
(b) Effects of overexposure.
(i) Short-term (acute) overexposure: Overexposure
to MDA may produce fever, chills, loss of appetite, vomiting,
jaundice. Contact may irritate skin, eyes, and mucous membranes.
Sensitization may occur.
(ii) Long-term (chronic) exposure. Repeated
or prolonged exposure to MDA, even at relatively low concentrations,
may cause cancer. In addition, damage to the liver, kidneys,
blood, and spleen may occur with long-term exposure.
(iii) Reporting signs and symptoms: You should
inform your employer if you develop any signs or symptoms
which you suspect are caused by exposure to MDA including
yellow staining of the skin.
(3) Protective clothing and equipment.
(a) Respirators. Respirators are required for
those operations in which engineering controls or work practice
controls are not adequate or feasible to reduce exposure to
the permissible limit. If respirators are worn, they must
have the joint Mine Safety and Health Administration and National
Institute for Occupational Safety and Health (NIOSH) seal
of approval, and cartridges or canisters must be replaced
as necessary to maintain the effectiveness of the respirator.
If you experience difficulty breathing while wearing a respirator,
you may request a positive pressure respirator from your employer.
You must be thoroughly trained to use the assigned respirator,
and the training will be provided by your employer. MDA does
not have a detectable odor except at levels well above the
permissible exposure limits. Do not depend on odor to warn
you when a respirator canister is exhausted. If you can smell
MDA while wearing a respirator, proceed immediately to fresh
air. If you experience difficulty breathing while wearing
a respirator, tell your employer.
(b) Protective clothing. You may be required
to wear coveralls, aprons, gloves, face shields, or other
appropriate protective clothing to prevent skin contact with
MDA. Where protective clothing is required, your employer
is required to provide clean garments to you, as necessary,
to assure that the clothing protects you adequately. Replace
or repair impervious clothing that has developed leaks. MDA
should never be allowed to remain on the skin. Clothing and
shoes which are not mpervious to MDA should not be allowed
to become contaminated with MDA, and if they do, the clothing
and shoes should be promptly removed and decontaminated. The
clothing should be laundered to remove MDA or discarded. Once
MDA penetrates shoes or other leather articles, they should
not be worn again.
(c) Eye protection. You must wear splashproof
safety goggles in areas where liquid MDA may contact your
eyes. Contact lenses should not be worn in areas where eye
contact with MDA can occur. In addition, you must wear a face
shield if your face could be splashed with MDA liquid.
(4) Emergency and first aid procedures.
(a) Eye and face exposure. If MDA is splashed
into the eyes, wash the eyes for at least 15 minutes. See
a doctor as soon as possible.
(b) Skin exposure. If MDA is spilled on your
clothing or skin, remove the contaminated clothing and wash
the exposed skin with large amounts of soap and water immediately.
Wash contaminated clothing before you wear it again.
(c) Breathing. If you or any other person breathes
in large amounts of MDA, get the exposed person to fresh air
at once. Apply artificial respiration if breathing has stopped.
Call for medical assistance or a doctor as soon as possible.
Never enter any vessel or confined space where the MDA concentration
might be high without proper safety equipment and at least
one other person present who will stay outside. A life line
should be used.
(d) Swallowing. If MDA has been swallowed and
the patient is conscious, do not induce vomiting. Call for
medical assistance or a doctor immediately.
(5) Medical requirements. If you are exposed to
MDA at a concentration at or above the action level for more
than 30 days per year, or exposed to liquid mixtures more than
15 days per year, your employer is required to provide a medical
examination, including a medical history and laboratory tests,
within 60 days of the effective date of this standard and annually
thereafter. These tests shall be provided without cost to you.
In addition, if you are accidentally exposed to MDA (either
by ingestion, inhalation, or skin/eye contact) under conditions
known or suspected to constitute toxic exposure to MDA, your
employer is required to make special examinations and tests
available to you.
(6) Observation of monitoring. Your employer is
required to perform measurements that are representative of
your exposure to MDA and you or your designated representative
are entitled to observe the monitoring procedure. You are entitled
to observe the steps taken in the measurement procedure and
to record the results obtained. When the monitoring procedure
is taking place in an area where respirators or personal protective
clothing and equipment are required to be worn, you and your
representative must also be provided with, and must wear, the
protective clothing and equipment.
(7) Access to records. You or your representative
are entitled to see the records of measurements of your exposure
to MDA upon written request to your employer. Your medical examination
records can be furnished to your physician or designated representative
upon request by you to your employer.
(8) Precautions for safe use, handling, and storage.
(a) Material is combustible. Avoid strong acids
and their anhydrides. Avoid strong oxidants. Consult supervisor
for disposal requirements.
(b) Emergency clean-up. Wear self-contained
breathing apparatus and fully clothe the body in the appropriate
personal protective clothing and equipment.
(b) Flash point: 226 degrees C. (439 degrees
F.) Cleveland open cup.
(c) Extinguishing media: Water spray; dry chemical;
carbon dioxide.
(d) Special fire fighting procedures: Wear self-contained
breathing apparatus and protective clothing to prevent contact
with skin and eyes.
(e) Unusual fire and explosion hazards: Fire
or excessive heat may cause production of hazardous decomposition
products.
(f) Hazardous polymerization: Will not occur.
(4) Reactivity data.
(a) Stability: Stable
(b) Incompatibility: Strong oxidizers.
(c) Hazardous decomposition products: At with
any other organic material, combustion may produce carbon
monoxide. Oxides of nitrogen may also be present.
(5) Spill and leak procedures.
(a) Sweep material onto paper and place in fiber
carton.
(b) Package appropriately for safe feed to an
incinerator or dissolve in compatible waste solvents prior
to incineration.
(c) Dispose of in an approved incinerator equipped
with afterburner and scrubber or contract with licensed chemical
waste disposal service.
(d) Discharge treatment or disposal may be subject
to federal, state, or local laws.
(e) Wear appropriate personal protective equipment.
(6) Special storage and handling precautions.
(a) High exposure to MDA can occur when transferring
the substance from one container to another. Such operations
should be well ventilated and good work practices must be
established to avoid spills.
(b) Pure MDA is a solid with a low vapor pressure.
Grinding or heating operations increase the potential for
exposure.
(c) Store away from oxidizing materials.
(d) Employers shall advise employees of all
areas and operations where exposure to MDA could occur.
(7) Housekeeping and hygiene facilities.
(a) The workplace should be kept clean, orderly,
and in a sanitary condition. The employer should institute
a leak and spill detection program for operations involving
MDA in order to detect sources of fugitive MDA emissions.
(b) Adequate washing facilities with hot and
cold water are to be provided and maintained in a sanitary
condition. Suitable cleansing agents should also be provided
to assure the effective removal of MDA from the skin.
(8) Common operations. Common operations in which
exposure to MDA is likely to occur include the following: Manufacture
of MDA; manufacture of methylene diisocyanate; curing agent
for epoxy resin structures; wire coating operations; and filament
winding.
WAC
296-62-07658 Appendix C to WAC 296-62-076--Medical surveillance
guidelines for MDA.
(1) Route of entry:
Inhalation; skin absorption; ingestion. MDA can
be inhaled, absorbed through the skin, or ingested.
(2) Toxicology:
MDA is a suspect carcinogen in humans. There are
several reports of liver disease in humans and animals resulting
from acute exposure to MDA. A well documented case of an acute
cardiomyopathy secondary to exposure to MDA is on record. Numerous
human cases of hepatitis secondary to MDA are known. Upon direct
contact MDA may also cause damage to the eyes. Dermatitis and
skin sensitization have been observed. Almost all forms of acute
environmental hepatic injury in humans involve the hepatic parenchyma
and produce hepatocellular jaundice. This agent produces intrahepatic
cholestasis. The clinical picture consists of cholestatic jaundice,
preceded or accompanied by abdominal pain, fever, and chills.
Onset in about 60 percent of all observed cases is abrupt with
severe abdominal pain. In about 30 percent of observed cases,
the illness presented and evolved more slowly and less dramatically,
with only slight abdominal pain. In about 10 percent of the
cases only jaundice was evident. The cholestatic nature of the
jaundice is evident in the prominence of itching, the histologic
predominance of bile stasis, and portal inflammatory infiltration,
accompanied by only slight parenchymal injury in most cases,
and by the moderately elevated transaminase values. Acute, high
doses, however, have been known to cause hepatocellular damage
resulting in elevated SGPT, SGOT, alkaline phosphatase, and
bilirubin.
Absorption through the skin is rapid. MDA is metabolized
and excreted over a 48-hour period. Direct contact may be irritating
to the skin, causing dermatitis. Also MDA which is deposited
on the skin is not thoroughly removed through washing.
MDA may cause bladder cancer in humans. Animal
data supporting this assumption is not available nor is conclusive
human data. However, human data collected on workers at a helicopter
manufacturing facility where MDA is used suggests a higher incidence
of bladder cancer among exposed workers.
(3) Signs and symptoms:
Skin may become yellow from contact with MDA.
Repeated or prolonged contact with MDA may result
in recurring dermatitis (red-itchy, cracked skin) and eye irritation.
Inhalation, ingestion, or absorption through the skin at high
concentrations may result in hepatitis, causing symptoms such
as fever and chills, nausea and vomiting, dark urine, anorexia,
rash, right upper quadrant pain, and jaundice. Corneal burns
may occur when MDA is splashed in the eyes.
(4) Treatment of acute toxic effects/emergency
situation:
If MDA gets into the eyes, immediately wash eyes
with large amounts of water. If MDA is splashed on the skin,
immediately wash contaminated skin with mild soap or detergent.
Employee should be removed from exposure and given proper medical
treatment. Medical tests required under the emergency section
of the medical surveillance subsection (13)(d) must be conducted.
If the chemical is swallowed do not induce vomiting but remove
by gastric lavage.
WAC
296-62-07660 Appendix D to WAC
296-62-076--Sampling and analytical methods for MDA monitoring
and measurement procedures.
Measurements taken for the purpose of determining
employee exposure to MDA are best taken so that the representative
average 8-hour exposure may be determined from a single 8-hour
sample or two 4-hour samples. Short-time interval samples (or
grab samples) may also be used to determine average exposure
level if a minimum of five measurements are taken in a random
manner over the 8-hour work shift. Random sampling means that
any portion of the work shift has the same chance of being sampled
as any other. The arithmetic average of all such random samples
taken on one work shift is an estimate of an employee's average
level of exposure for that work shift. Air samples should be
taken in the employee's breathing zone (air that would most
nearly represent that inhaled by the employee).
There are a number of methods available for monitoring
employee exposures to MDA. The method WISHA currently uses is
included below.
The employer, however, has the obligation of selecting
any monitoring method which meets the accuracy and precision
requirements of the standard under his/her unique field conditions.
The standard requires that the method of monitoring must have
an accuracy, to a 95 percent confidence level, of not less than
plus or minus 25 percent for the select PEL.
WISHA methodology.
Sampling procedure.
Apparatus:
Samples are collected by use of a personal sampling
pump that can be calibrated within +5 percent of the recommended
flow rate with the sampling filter in line.
Samples are collected on 37 mm Gelman type A/E
glass fiber filters treated with sulfuric acid. The filters
are prepared by soaking each filter with 0.5 mL of 0.26N H2SO4.
(0.26 N H2SO4 can be prepared by diluting
1.5 mL of 36N H2SO4 to 200 mL with deionized
water.) The filters are dried in an oven at 100 degrees C. for
one hour and then assembled into three-piece 37 mm polystyrene
cassettes without backup pads. The front filter is separated
from the back filter by a polystyrene spacer. The cassettes
are sealed with shrink bands and the ends are plugged with plastic
plugs.
After sampling, the filters are carefully removed
from the cassettes and individually transferred to small vials
containing approximately 2 mL deionized water. The vials must
be tightly sealed. The water can be added before or after the
filters are transferred. The vials must be sealable and capable
of holding at least 7 mL of liquid. Small glass scintillation
vials with caps containing Teflon liners are recommended.
Reagents:
Deionized water is needed for addition to the
vials.
Sampling technique:
Immediately before sampling, remove the plastic
plugs from the filter cassettes.
Attach the cassette to the sampling pump with
flexible tubing and place the cassette in the employee's breathing
zone.
After sampling, seal the cassettes with plastic
plugs until the filters are transferred to the vials containing
deionized water.
At some convenient time within 10 hours of sampling,
transfer the sample filters to vials.
Seal the small vials lengthwise.
Submit at least one blank filter with each sample
set. Blanks should be handled in the same manner as samples,
but no air is drawn through them.
Record sample volumes (in L of air) for each sample,
along with any potential interferences.
Retention efficiency:
A retention efficiency study was performed by
drawing 100 L of air (80 percent relative humidity) at 1 L/min
through sample filters that had been spiked with 0.814 microgram
MDA. Instead of using backup pads, blank acid-treated filters
were used as backups in each cassette. Upon analysis, the top
filters were found to have an average of 91.8 percent of the
spiked amount. There was no MDA found on the bottom filters,
so the amount lost was probably due to the slight instability
of the MDA salt.
Extraction efficiency:
The average extraction efficiency for six filters
spiked at the target concentration is 99.6 percent.
The stability of extracted and derivatized samples
was verified by reanalyzing the above six samples the next day
using fresh standards. The average extraction efficiency for
the reanalyzed samples is 98.7 percent.
Recommended air volume and sampling rate:
The recommended air volume is 100 L.
The recommended sampling rate is 1 L/min.
Interferences (sampling):
MDI appears to be a positive interference. It
was found that when MDI was spiked onto an acid-treated filter,
the MDI converted to MDA after air was drawn through it.
Suspected interferences should be reported to
the laboratory with submitted samples.
Safety precautions (sampling):
Attach the sampling equipment to the employees
so that it will not interfere with work performance or safety.
Follow all safety procedures that apply to the
work area being sampled.
Analytical procedure:
Apparatus: The following are required for analysis.
A GC equipped with an electron capture detector.
For this evaluation a Hewlett Packard 5880 Gas Chromatograph
equipped with a Nickel 63 High Temperature Electron Capture
Detector and a Linearizer was used.
A GC column capable of separating the MDA derivative
from the solvent and interferences. A 6 ft X 2 mm ID glass column
packed with 3 percent OV-101 coated on 100/120 Gas Chrom Q or
a 25 meter DB-1 or DB-5 capillary column is recommended for
this evaluation.
A electronic integrator or some other suitable
means of measuring peak areas or heights.
Small resealable vials with Teflonlined caps capable
of holding 4 mL.
A dispenser or pipet for toluene capable of delivering
2.0 mL.
Pipets (or repipets with plastic or Teflon tips)
capable of delivering 1 mL for the sodium hydroxide and buffer
solutions.
A repipet capable of delivering 25 micro-L HFAA.
Syringes for preparation of standards and injection
of standards and samples into a GC.
Volumetric flasks and pipets to dilute the pure
MDA in preparation of standards.
Disposable pipets to transfer the toluene layers
after the samples are extracted.
Reagents:
0.5 NaOH prepared from reagent grade NaOH.
Toluene, pesticide grade. Burdick and Jackson
distilled in glass toluene was used.
Heptafluorobutyric acid anhydride (HFAA). HFAA
from Pierce Chemical Company was used.
pH 7.0 phosphate buffer, prepared from 136 g potassium
dihydrogen phosphate and 1 L deionized water. The pH is adjusted
to 7.0 with saturated sodium hydroxide solution.
4,4'-Methylenedianiline (MDA), reagent grade.
Standard preparation:
Concentrated stock standards are prepared by diluting
pure MDA with toluene. Analytical standards are prepared by
injecting uL amounts of diluted stock standards into vials that
contain 2.0 mL toluene.
25 µL HFAA are added to each vial and the vials
are capped and shaken for 10 seconds.
After 10 min, 1 mL of buffer is added to each
vial.
The vials are recapped and shaken for 10 seconds.
After allowing the layers to separate, aliquots
of the toluene (upper) layers are removed with a syringe and
analyzed by GC.
Analytical standard concentrations should bracket
sample concentrations. Thus, if samples fall out of the range
of prepared standards, additional standards must be prepared
to ascertain detector response.
Sample preparation:
The sample filters are received in vials containing
deionized water.
1 mL of 0.5N NaOH and 2.0 mL toluene are added
to each vial.
The vials are recapped and shaken for 10 min.
After allowing the layers to separate, approximately
1 mL aliquots of the toluene (upper) layers are transferred
to separate vials with clean disposable pipets.
The toluene layers are treated and analyzed.
Analysis:
GC conditions
Zone temperatures:
Column--220 degrees C.
Injector--235 degrees C.
Detector--335 degrees C.
C Gas flows, N2 Column--30 mL/min
He Column 0.9 mL/min. (capillary) with 30 mL/min.
ArCH4 (95/5) makeup gas
Injection volume: 5.0 uL
Column: 6 ft X 1/8 in ID glass, 3% OV-101 on 100/120
Gas Chrom Q or 25 meter x .25 mm DB-1 or DB-5 capillary
Retention time of MDA derivative: 2.5 to 3.5,
depending on column and flow
Chromatogram:
Peak areas or heights are measured by an integrator
or other suitable means.
A calibration curve is constructed by plotting
response (peak areas or heights) of standard injections versus
mg of MDA per sample. Sample concentrations must be bracketed
by standards.
Interferences (analytical):
Any compound that gives an electron capture detector
response and has the same general retention time as the HFAA
derivative of MDA is a potential interference. Suspected interferences
reported to the laboratory with submitted samples by the industrial
hygienist must be considered before samples are derivatized.
GC parameters may be changed to possibly circumvent
interferences.
Retention time on a single column is not considered
proof of chemical identity. Analyte identity should be confirmed
by GC/MS if possible.
Calculations:
The analyte concentration for samples is obtained
from the calibration curve in terms of mg MDA per sample. The
extraction efficiency is 100 percent. If any MDA is found on
the blank, that amount is subtracted from the sample amounts.
The air concentrations are calculated using the following formulae:
Microgram/m3 = (microgram MDA per sample) (1000)/(L
of air sampled) ppb = (microgram/m3) (24.46)/(198.3)
= (microgram/m3)(0.1233) where 24.46 is the molar
volume at 25 degrees C. and 760 mm Hg.
Safety precautions (analytical):
Avoid skin contact and inhalation of all chemicals.
Restrict the use of all chemicals to a fume hood
if possible.
Wear safety glasses and a lab coat at all times
while in the lab area.
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