Ethylene OxideChapter 296-855, WAC |
Effective Date: 01/01/06 |
Basic Rule |
![]()
Your Responsibility
To evaluate employee exposure and protect employees from ethylene oxide
IMPORTANT:
- The requirements in basic rules apply to all employers covered by the scope of this chapter, WAC 296-855-100. Additional sections may apply to you, based on employee exposure monitoring results. Turn to the Scope, WAC 296-855-100, and follow Table 1.
| Preventive practices |
|
| Exposure control areas |
|
|
Personal protective equipment (PPE) |
WAC 296-855-20040 |
| Exposure evaluations | WAC 296-855-20050 |
| Notification | WAC 296-855-20060 |
| Exposure records | WAC 296-855-20070 |
| Documentation records | WAC 296-855-20080 |
| Training | WAC 296-855-20090 |
![]()
Preventive practices
You must
- Make sure that all containers of EtO whose
contents are capable of causing employee exposure above the
action level or above the STEL are labeled, tagged, or marked
with this warning:
Danger
Contains Ethylene Oxide
Cancer Hazard and Reproductive Hazard
AND - A warning stating that breathing airborne concentrations of EtO is hazardous.
- Keep container labels free of statements that contradict or detract from the labels’ hazard warning.
|
|
Note: EtO is highly flammable and should be
kept in a tightly covered container, and in a cool, well-ventilated
area away from any type of ignition source. |
You must
|
- Make sure warning labels remain on containers of EtO when these containers are transported.
Exposure control areas
You must
- Establish temporary or permanent exposure
control areas where airborne concentrations of ethylene oxide
(EtO) exceed or could exceed the permissible exposure limits
(PELs) by doing all the following:
- – Clearly identify the boundaries of exposure control areas in any way that minimizes employee access.
- – Post signs
at access points to exposure control areas that:
- Are easy to read (for example, they
are kept clean and well lit)
AND - Include this warning:
- Are easy to read (for example, they
are kept clean and well lit)
DANGER
ETHYLENE OXIDE CANCER AND REPRODUCTIVE HAZARD AUTHORIZED PERSONNEL ONLY RESPIRATORS AND PROTECTIVE CLOTHING MAY BE REQUIRED TO BE WORN IN THIS AREA |
- Keep signs and areas near them free of statements that contradict or detract from their message.
|
|
Note: This requirement doesn't prevent you from
posting other signs. |
You must
- Allow only authorized personnel to enter exposure control areas.
|
|
Note:
|
You must
- Make sure employees entering exposure control areas have appropriate respirators available for use.
- Prevent all of the following activities from occurring in exposure control areas:
- – Eating food
- – Drinking beverages
- – Smoking
- – Chewing tobacco or gum
- – Applying cosmetics
- – Storing food, beverages, or cosmetics.
Personal protective equipment (PPE)
You must
- Make sure employees wear appropriate PPE as protection from skin or eye contact with ethylene oxide (EtO), liquid EtO, or EtO solutions.
- Provide appropriate PPE at no cost to employees.
Exposure evaluations
IMPORTANT:
- This section applies when there is a potential for airborne exposure to ethylene oxide (EtO) in your workplace.
- When you conduct an exposure evaluation in a workplace where an employee uses a respirator, the protection provided by the respirator isn't considered.
- Following this section will also meet the requirements to identify and evaluate respiratory hazards found in chapter 296-841 WAC, Airborne contaminants.
- Conduct an employee exposure evaluation to
accurately determine airborne concentrations of EtO by completing
Steps 1 through 7 of the exposure evaluation process, each time
any of the following apply:
- – No evaluation has been conducted
- – Changes have occurred in any of
the following areas that may result in new or increased
employee exposures:
- Production
- Processes
- Personnel
- Exposure controls such as ventilation systems or work practices.
- – You have any reason to suspect new or increased employee exposure may occur.
- Provide affected employees and their designated representatives an opportunity to observe any exposure monitoring during Step 6 of the exposure evaluation process.
- Make sure observers entering areas with EtO
exposure:
- – Are provided with and use the
same protective clothing, respirators, and other personal
protective equipment (PPE) that employees working in the
area are required to use;
AND - – Follow all safety and health requirements that apply.
- – Are provided with and use the
same protective clothing, respirators, and other personal
protective equipment (PPE) that employees working in the
area are required to use;
Exposure evaluation process
Step 1: Identify all employees who have potential exposure to airborne ethylene oxide (EtO) in your workplace.
Step 2: Identify operations where employee exposures could exceed EtO’s 15-minute short-term exposure limit (STEL) of 5 parts per million (ppm).
Step 3: Select employees from those working in the operations you identified in Step 2 who will have their STEL exposures measured.
Step 4: Select employees from those identified in Step 1 who will have their 8-hour exposures monitored.
- Make sure the exposures of the employees selected represent 8-hour exposures for all employees identified in Step 1 including each job classification, work area, and shift.
- If you expect all employee exposures to be below the action level (AL), you can choose to limit your selection to those employees reasonably believed to have the highest exposures. If you find these employees’ exposure to be above the AL, then you’ll need to repeat Step 4 to represent all employees identified in Step 1.
|
|
Note: You can use Steps 3 through 6 of this
process to create a written description of the procedure
used for obtaining representative employee exposure monitoring
results, which is a requirement in Exposure records, WAC
296-855-20070. |
|
Step 5: Determine how you will obtain accurate employee exposure monitoring results. Select and use an air monitoring method with a confidence level of 95 percent, that’s accurate to:
- ±25 percent when concentrations are potentially above the AL or 8-hour time-weighted average of 1 part per million (ppm).
- ±35 percent when concentrations are potentially above the AL of 0.5 ppm or the STEL of 5 ppm.
|
|
Note:
|
Step 6: Obtain employee
monitoring results by collecting air samples
representing employees identified in Steps 3 and 4.
- Collect STEL samples for employees and operations selected in Step 3.
- Collect samples representing the 8-hour exposure, for at least one shift, for each employee selected in Step 4.
- Make sure samples are collected from each selected employee’s breathing zone.
|
|
Note:
|
Step 7: Have the samples you collected analyzed to obtain monitoring results for 8-hour and STEL exposures.
- Determine if employee exposure monitoring
results are above or below the following values:
- – 8-hour time-weighted average (TWA8) of one ppm
- – 15-minute short-term exposure limit (STEL) of 5 ppm
- – 8-hour action level (AL) of 0.5 ppm.

Note:
- You may contact your local WISHA
consultant for help:
– Interpreting data or other information.
– Determining 8-hour or 15-minute employee exposure monitoring results.
Notification
You must
- Provide written notification of exposure monitoring results to employees represented by your exposure evaluation, within 5 business days after monitoring results become known to you.
- In addition, when employee exposure monitoring
results are above either the TWA8 or STEL permissible
exposure limit (PEL), provide written notification of all the
following within 15 business days after the results become known
to you:
- – Corrective actions being taken
and a schedule for completion
AND - – Any reason why exposures can't be lowered to below the PELs.

Note:
- You can either notify employees individually or post the notifications in areas readily accessible to affected employees.
- Posted notification may need specific information that allows affected employees to determine which monitoring results apply to them.
- Notification may be:
- – In any written form, such as hand-written or e-mail.
- – Limited to the required information, such as exposure monitoring results.
- – When notifying employees about corrective actions, your notification may refer them to a separate document that is available and provides the required information.
- – Corrective actions being taken
and a schedule for completion
Exposure records
You must
- Establish and keep complete and accurate records for all exposure monitoring evaluations conducted under this chapter. Make sure the record includes, at least:
- – The name, unique identifier, and job classification of:
- The employee sampled;
AND - All other employees represented by the
sampled employee.
- – A description of the methods used to obtain exposure monitoring results and evidence of the methods’ accuracy.
- – The operation being monitored for employee exposure to EtO.
- – A description of the procedure used to obtain representative employee exposure monitoring results.
- – The date, number, duration, location, and the result of each sample taken.
- – Any environmental conditions that could affect exposure concentration measurements.
- – Any personal protective equipment (PPE) worn by the employee including the type of respirator.

Note:
You can use Steps 3 through 6 of the exposure evaluation process in Exposure evaluations, WAC 296-855-20050, to create a description of the procedure you used for obtaining representative employee exposure monitoring results.
You must
- Keep exposure monitoring records for at least 30 years.
|
|
Reference:
|
Documentation records
You must
- Keep documentation you develop, of the processing, use, or handling of products made from or containing EtO, that conclusively demonstrates that the action level or STEL for EtO can't be exceeded under any foreseeable conditions of use.
- Include the following in the documentation
record:
- – The product that is the subject of the documentation
- – The source of the data
- – Any testing protocol, results of testing, and/or analysis of the product for the release of EtO
- – A description of the operation
where the product is used and how the data support your
conclusion
and - – Other data relevant to the operations, materials, processing, or employee exposures covered by your conclusion.
- Maintain the documentation record for as long as you rely on your conclusion that the action level and STEL can't be exceeded.
Training
You must
- Train employees who are potentially exposed above the:
- – Action level (AL) 0.5 parts per
million (ppm)
OR - – 15-minute short-term exposure limit (STEL) of 5 ppm.
- Provide training:
- – At the time of initial assignment
AND - – Then at least every 12 months.
- Make sure training and information includes all of the following:
- – The requirements of this chapter
- – The location and availability of this chapter
- – The purpose of medical evaluations and a description of your medical evaluation program required in Medical evaluations, WAC 296-855-30030 in this chapter
- – Monitoring procedures and observations to detect the presence or release of EtO
- – The physical and health hazards of EtO
- – Actions employees can take to protect themselves from EtO exposure such as work practices, emergency procedures, and PPE
- – The details of your hazard communication program required by another chapter, Employer chemical hazard communication, WAC 296-800-170
- – Operations in employee work areas where EtO is present
- – The following information found in the General Occupational Health Standards, chapter 296-62 WAC:
- The Substance Safety Data Sheet, WAC 296-62-07383 Appendix A
- The Substance Technical Guidelines, WAC 296-62-07385 Appendix B
- Medical Surveillance Guidelines, WAC 296-62-07387 Appendix C.
