WISHA Regional Directive 89-8

WRD 89-8

SUBJECT: Application Requirements for (WAC 296-62-07515) Permissible Exposure Limits (PELs) - Special Instructions and Stays.

I. Purpose: This Directive provides supplemental instruction and guidelines to Safety and Health personnel for enforcement of the Air Contaminant Standard regarding exceptions and stays to PELs.

II. Background: Comments, inquiries, and instructions from OSHA and from the June 6, 1989 WISHA public hearing regarding PELs as amended were received and evaluated. It was determined that a limited number of exceptions and stays were required to provide compatibility with the OSHA requirements. The following items were reviewed as basis for the decisions in the Application section:

Federal Register Vol. 54, No. 12 dated January 19, 1989 as adopted and in response to 29 CFR 1910.1000(f)(4).

Federal letter from James W. Lake of September 12, 1989 containing "updated" changes to 29 CFR 1910.1000 as a result of legal challenges presented to OSHA.

Determinations as issued in a WISHA letter to John E. Woodring on June 30, 1989 regarding public hearing comments.

U.S. Court of Appeals, Eleventh District Court Settlement Agreement pursuant to Federal Rule of Appellate Procedure (42b) that Docket Numbers 89-7249 and 82-7250 be dismissed with prejudice.

III. Application: The following stays, exemptions and methods shall apply to existing exposure limits for the substances listed:

Carbon Disulfide. WISHA's assessment of the feasibility of this limit indicates that, under normal operating conditions, a 4 ppm TWA PEL and a 12 ppm STEL are generally achievable by using engineering controls and work practices; respiratory protection may be required during certain operations in rayon and sausage- casing production, such as maintenance tasks or opening of the production lines. Specific operations for which WISHA will accept the use of respirators for compliance purposes include the following:

Opening windows and hoods to remove filament bundles and to change spinerettes (in SIC 28);

Effecting product-line changes (in SIC 28);

Unloading xanthate from the baratte, and aligning strands in the extrusion cabinet (in SIC 30); and

Manually puncturing casings at the extrusion nozzles in the cellulosic food casing industry (in SIC 30).

Carbon Monoxide. Evidence in the OSHA public hearing indicates that the ceiling limit cannot be regularly achieved with engineering controls and work practices in specific operations in SIC 33. These operations are: blast furnace operations, vessel blowing at basic oxygen furnaces, and sinter plant operations. For these operations, WISHA will permit the use of NIOSH respirators.

Note: In all industries, for measurement and analysis purposes the 200 ppm ceiling limit is to be determined by averaging a five minute exposure measurement.

Methyl ethyl ketone peroxide. The OSHA preamble to the new federal standard for air contaminants (PELs) contained comments regarding engineering feasibility. Comments were also received at the WISHA public hearing relating to the engineering feasibility. Accordingly, respiratory protection will be allowed to offset the possible infeasibility of engineering controls and work practices for ceiling exposure levels less than 0.7 ppm. Engineering controls will be required at higher levels.

Styrene. In two-operations in the boat-building industry, manual layup and sprayup, there is insufficient data to indicate that compliance can generally be achieved with engineering and work practice controls. For these boat-building operations, employers may use any combination of engineering controls, work practices, and respiratory protection to achieve the limits. The employer must use engineering controls and work practices to achieve compliance with WISHA's former limits for styrene which are: 100 ppm, eight hour TWA and 200 ppm STEL.

Having previously determined that compliance with the new styrene limits may not be achievable solely with engineering and work practice controls for manual layup and stayup operations in boat-building, OSHA has concluded and WISHA concurs, that the same considerations apply to some other operations in the reinforced plastics industry comparable to boat-building.

In a November 20, 1989 letter to Keller and Heckman, Attorney for the Fiberglass Fabrication Association and the Society of the Plastics Industry, Incorporated, regarding the Settlement Agreement (Docket Number 89-7249 and Number 89-7250 of the U.S. Court of Appeals, (Eleventh Circuit Court)), the federal PEL for styrene is amended with the following guidelines:

OSHA has recognized and WISHA concurs that the PELs for styrene may not be achievable solely through engineering and work practice controls for operations comparable to boat-building in that they: (1) employ the manual layup and sprayup process, (2) the manufactured items utilize the same equipment and technology as that found in boat- building, and (3) the same considerations of large part-size, configuration interfering with air-flow control techniques, and resin usage apply. Examples of operations comparable to boat-building would include the manufacture of large above-ground or below-ground storage tanks, large parts for recreational vehicles, and large duct work.

Because it is impossible to define in advance every manual layup and sprayup process for which compliance may not be feasible solely through engineering and work practice controls, some guidelines concerning part size and configuration issues are necessary. The primary question for manual layup and sprayup operations is whether the part's size and configuration interfere with normal air-flow techniques. For example, a flat sheet measuring 10 feet by 20 feet does not present air-flow control problems, whereas a 10-foot in diameter by 20-foot storage tank might. Generally speaking, if a part has a surface area greater than 250 square feet or occupies a volume greater than 150 cubic feet, the employer may achieve compliance with a mix of engineering, work practice controls. Similarly, if a part exceeds 30 feet in length, it may be appropriate to supplement engineering and work practice controls with respirators to achieve compliance.

For operations making parts (such as tubs and vanities) that do not meet the guidelines described above, commencing December 31, 1992 the hierarchy of controls specified in WAC 296-62-07501 will apply to reduce styrene exposures to the new 50 ppm TWA and 100 ppm STEL. It should be noted that between September 1, 1989 and December 31, 1992 the new limits can be achieved by any reasonable combination of controls, but the transitional limits must be achieved by the hierarchy of controls specified in WAC 296-62-07501.

Subtilisin. For monitoring purposes of subtilisin, a one-hour high volume sample rather than a fifteen-minute sample will be used for enforcement of the STEL.

Sulfur Dioxide. Evidence has been made available that for steel and nonferrous metal industries that the STEL cannot be regularly achieved with engineering controls and work practices in specific operations in SIC 33 which involves furnace areas in nonferrous metal smelters, blast furnace operations and the sulfur plant. WISHA will permit the use of NIOSH approved respirators for these operations.

Indefinite STAY of Enforcement. Enforcement of the PELs for ethylidine norbornene, hexafluoroactone, oxygen difluoride, phenylphosphine, and sulfur pentafluoride are indefinitely stayed until OSHA publishes a notice in the Federal Register that sampling and analytical technique are available. Reference 29 CFR 1910.1000 (f)(4)).

Note: Although the CFR includes exclusions for aluminum alkyls and mercury alkyls, WISHA does not exclude compliance with these substances as there are existing sampling techniques. WISHA personnel evaluating these two substances must contact the hygiene laboratory prior to sampling.

WISHA "Chemical Mixture", WAC 296-62-07507. The WISHA "chemical mixture" formula is the same as OSHA's. In addition, WAC 296-62- 07507 states that mixture consideration be given where there are "....similar health affects." Accordingly, as indicated by OSHA and accepted by WISHA, acetone and styrene shall not be combined for the purpose of calculating the mixture effects.

IV. Action: WISHA personnel will use the guidelines set forth in the application section for the enforcement of WAC 296-62-07515 as applicable.

V. Effective Date: This WISHA Regional Directive shall become effective on January 1, 1990 and remain in effect for eighteen months, until incorporation into regulation, or cancellation.