Ethylene oxide scope

Yes — under 1910.1047(a)(1) the EtO standard applies to all occupational exposures to ethylene oxide (EtO) except where paragraph (a)(2) provides an exemption.

• If your workers can be exposed to airborne EtO at work, the standard applies unless you can rely on the narrow exemption in 1910.1047(a)(2).
• When you claim an exemption under (a)(2), you must keep supporting records as required by 1910.1047(a)(3) and 1910.1047(k)(1).

You may exempt a product containing EtO only if objective data reasonably demonstrate the product cannot release EtO into the air at or above the action level (0.5 ppm) and is not reasonably expected to release EtO above the excursion limit under the worst expected conditions of processing, use, or handling, per 1910.1047(a)(2).

• "Objective data" are factual, test-based or manufacturer-provided data that show the product's realistic maximum airborne emissions are below the standard's limits.
• The data should cover the conditions that could cause the greatest possible release (e.g., heating, cutting, intended use).
• Keep documentation of the data and your rationale as required by 1910.1047(a)(3) and 1910.1047(k)(1).

You must keep records of the objective data and the basis for relying on them to support the exemption, as required by 1910.1047(a)(3) and the recordkeeping provisions in 1910.1047(k)(1).

• Records should document the data source (e.g., supplier tests, published studies), the conditions evaluated, and why those data cover the worst-case handling or use.
• Keep the records for the time specified in 1910.1047(k)(1) and make them available to the Assistant Secretary, the Director, affected employees, and their representatives on request.

The action level for ethylene oxide is 0.5 parts per million (ppm) calculated as an eight-hour time-weighted average (8-hour TWA), per 1910.1047(b).

• When monitoring, if an employee's 8-hour TWA is at or above 0.5 ppm, the employer must follow the monitoring frequency and control requirements triggered by the action level (see 1910.1047(d)).

The permissible exposure limit (PEL) for EtO is 1 part per million (1 ppm) as an 8-hour time-weighted average (8-hour TWA), according to 1910.1047(c)(1).

• Employers must ensure employee exposures do not exceed this 1 ppm 8-hour TWA by using engineering controls, work practices, and, when necessary, respiratory protection (see 1910.1047(f)).

The EtO excursion limit is 5 parts per million (5 ppm) averaged over a 15-minute sampling period, as specified in the standard's exposure limits and sampling requirements in 1910.1047(c)(2) and the short-term sampling language in 1910.1047(d)(1).

• Short-term (15-minute) samples must represent the operations most likely to cause excursions above that 5 ppm limit.

You must collect breathing-zone air samples that represent each employee's 8-hour TWA and 15-minute short-term exposures, per 1910.1047(d)(1)(i).

• For 8-hour TWA exposures, take one or more full-shift samples for each shift and job classification in each work area (1910.1047(d)(1)(ii)).
• For 15-minute excursion monitoring, sample the tasks or operations most likely to exceed the excursion limit on each shift and job classification (1910.1047(d)(1)(ii)).
• If you can document equivalent exposure across shifts for similar operations, you may monitor just one representative shift (1910.1047(d)(1)(iii)).

Initial monitoring is required for any workplace or operation covered by the standard unless you qualify for the product exemption in [1910.1047(a)(2)], as stated in 1910.1047(d)(2)(i).

• You may rely on monitoring performed after June 15, 1983 if those results meet all the other requirements of the monitoring section (1910.1047(d)(2)(ii)).
• You may also rely on earlier monitoring that covered excursions provided it satisfies the standard's other monitoring requirements (1910.1047(d)(2)(iii)).

Repeat monitoring frequency is based on prior results: if exposures are at or above the action level but at or below the 8-hour TWA, repeat monitoring at least every 6 months; if above the 8-hour TWA, repeat at least every 3 months; if above the 15-minute excursion limit, repeat at least every 3 months and more often as needed, as described in 1910.1047(d)(3).

• See 1910.1047(d)(3)(i) for the 6-month trigger and 1910.1047(d)(3)(ii) and 1910.1047(d)(3)(iv) for the quarterly requirements.

You may change the monitoring schedule or discontinue monitoring only when the standard's criteria are met: you can alter quarterly monitoring to semiannual for an employee when two consecutive measurements (taken at least 7 days apart) show exposures have decreased to or below the 8-hour TWA, and you may discontinue TWA or excursion monitoring when initial or periodic monitoring shows exposures below the action level or excursion limit on two consecutive measurements taken at least 7 days apart, per 1910.1047(d)(3)(iii) and 1910.1047(d)(4).

• For termination of TWA monitoring see 1910.1047(d)(4)(i)-(ii) and 1910.1047(d)(4)(ii).
• For excursion monitoring termination see 1910.1047(d)(4)(iii)-(iv).

You must institute monitoring whenever there is a change in production, process, control equipment, personnel, or work practices that may result in new or additional EtO exposures, or whenever you have any reason to suspect a change may cause new exposures, according to 1910.1047(d)(5).

• Practical examples include installing new sterilizers, changing sterilant handling procedures, or modifying ventilation that could alter EtO concentrations.

Monitoring must be accurate to a 95 percent confidence level with specified tolerances: within ±25% for airborne concentrations at the 1 ppm TWA and within ±35% at the action level (0.5 ppm), and monitoring must also be within ±35% at the excursion limit, per 1910.1047(d)(6)(i) and 1910.1047(d)(6)(ii).

• Use validated sampling and analytical methods that can meet these accuracy/confidence requirements when demonstrating compliance.

You must notify each affected employee of monitoring results within 15 working days after you receive them, either individually in writing or by posting in an accessible location, as required by 1910.1047(d)(7)(i).

• If results show the TWA or excursion limit was exceeded, the written notification must include the corrective action you are taking to reduce exposures to or below the limits, per 1910.1047(d)(7)(ii).

You must establish a regulated area wherever occupational exposure to EtO may exceed the TWA or wherever EtO concentration exceeds or can reasonably be expected to exceed the excursion limit, and access must be limited to authorized persons, with the area demarcated to minimize the number of employees within it, as stated in 1910.1047(e)(1)-(3).

• Authorized persons include those whose duties require entry and designated employee representatives observing monitoring per the standard.
• Demarcation can be signs, barriers, or other controls that effectively restrict access and reduce exposure to others.

Yes — employers must institute engineering controls and work practices to reduce exposures to or below the TWA and excursion limit where feasible; certain operations are listed as generally infeasible for engineering controls, including collection of quality assurance samples, removal of biological indicators, loading/unloading tank cars, changing EtO tanks on sterilizers, and vessel cleaning, per 1910.1047(f)(1)(i)-(iii).

• Where engineering controls alone cannot reduce exposure to required levels, you must use the feasible controls to lower exposures as much as possible and supplement them with respiratory protection that meets 1910.1047(g).
• For the operations listed as generally infeasible, engineering controls are required only if the Assistant Secretary demonstrates they are feasible (1910.1047(f)(1)(iii)).

When the TWA or excursion limit is exceeded, you must establish and implement a written program to reduce exposures by engineering and work practice controls and by using respiratory protection where required or permitted, per 1910.1047(f)(2)(i).

• The program must include a schedule for periodic leak detection surveys and a written emergency plan as specified in 1910.1047(f)(2)(ii) and 1910.1047(h)(i).
• You must develop written plans and furnish them upon request to the Assistant Secretary, the Director, affected employees and their representatives, review the plans at least every 12 months, and update as necessary (1910.1047(f)(2)(iii)).
• You may not use employee rotation as a means of complying with the TWA or excursion limit (1910.1047(f)(2)(iv)).

No — the standard expressly prohibits using a schedule of employee rotation as a means of compliance with the TWA or excursion limit, as stated in 1910.1047(f)(2)(iv).

• Instead, implement engineering controls, work practice changes, and respiratory protection where necessary to reduce exposures for each employee.

Respiratory protection must be used whenever feasible engineering controls and work practices cannot reduce employee exposure to or below the TWA and excursion limit, and to supplement such controls to reduce exposure to the lowest achievable level, as required by 1910.1047(f)(1)(ii) and governed by 1910.1047(g)(1).

• When respirators are required, follow the respirator program and selection rules in the respiratory protection portion of the EtO standard (1910.1047(g)).

You must take 15-minute short-term samples for operations most likely to produce exposures above the excursion limit on each shift for each job classification in each work area, according to 1910.1047(d)(1)(ii).

• Typical examples include activities such as container opening, maintenance tasks, loading/unloading sterilizers, or any task that could produce short, high-concentration releases of EtO.

The compliance program must include a written plan for emergency situations as specified in 1910.1047(h)(i) and employers must include a schedule for periodic leak detection surveys as part of the compliance program per 1910.1047(f)(2)(ii).

• The emergency plan should address likely release scenarios (e.g., equipment failures, ruptures), immediate response steps, evacuation and medical procedures, and notification and mitigation measures.
• Keep the emergency plan written, accessible to affected employees, and review/update it at least annually as part of your compliance program (1910.1047(f)(2)(iii)).

"Employee exposure" is defined as the exposure to airborne EtO that would occur if the employee were not using respiratory protective equipment, per the definitions in 1910.1047(b).

• This means you must assess and monitor exposures based on the unprotected breathing zone concentration, and not reduce monitoring or control obligations because employees wear respirators.

An "emergency" includes any occurrence such as equipment failure, rupture of containers, or failure of control equipment that is likely to or does result in an unexpected significant release of EtO, according to the standard's definitions in 1910.1047(b).

• If such an event occurs, follow your written emergency plan required by 1910.1047(h)(i) to protect employees and notify appropriate authorities.

No — the standard allows reliance only on monitoring performed after June 15, 1983 if it satisfies all other monitoring requirements, per 1910.1047(d)(2)(ii).

• If you have older data, you should evaluate whether it meets current sampling accuracy, representativeness, and documentation requirements; otherwise perform new initial monitoring.

The written notification must state the corrective action being taken by the employer to reduce employee exposure to or below the TWA and/or the excursion limit whenever monitoring indicates those limits were exceeded, as required by 1910.1047(d)(7)(ii).

• Include timing for corrective steps, engineering or administrative controls being implemented, and whether interim respiratory protection is required.

You must demarcate regulated areas in any manner that minimizes the number of employees within them, per 1910.1047(e)(3).

• Practical measures include clear signage, physical barriers or fencing, controlled access points, and written procedures restricting entry to authorized personnel only.
• The key compliance test is that the demarcation effectively limits access and exposure, not the specific type of barrier used.

Employers must provide respirators whenever they are required by 1910.1047: during periods needed to install or implement feasible engineering/work-practice controls, for work where controls aren’t feasible (like maintenance, repair, or vessel cleaning), when controls are not yet sufficient to bring exposures below the TWA, and in emergencies. See 1910.1047(g)(1)(i)-(iv) and 1910.1047(g)(1)(ii).

The employer must implement a written respiratory protection program that complies with the elements of 29 CFR 1910.134 specified in the EtO standard (that is, 1910.134(b) through (d) (except (d)(i)(iii)), and (f) through (m)) and that covers every employee required to use a respirator for EtO. See 1910.1047(g)(2) and the referenced 1910.134 program requirements.

No — employers must not select or use half masks of any type for EtO because EtO may cause eye irritation or injury; they must select the respirators specified in 1910.134(d)(3)(i)(A). See 1910.1047(g)(3)(i) and the respirator selection guidance in 1910.134(d)(3)(i)(A).

Each air‑purifying, full facepiece respirator must be equipped with a front‑ or back‑mounted canister that is approved for protection against ethylene oxide. See 1910.1047(g)(3)(ii).

For escape, employers may provide any respirator that is permitted for use under paragraphs (g)(3)(i) and (ii) of the EtO standard — in other words, an appropriate full facepiece air‑purifying respirator with an EtO‑approved canister or other permitted respirators listed in those paragraphs. See 1910.1047(g)(3)(iii) and 1910.1047(g)(3)(ii).

Respirators may be used during the periods necessary to install or implement feasible engineering and work‑practice controls to limit worker exposure to EtO. Employers should use respirators only as a temporary measure while permanent controls are put in place. See 1910.1047(g)(1)(i).

When employees could have eye or skin contact with EtO or EtO solutions, the employer must select and provide appropriate protective clothing or other equipment at no cost and must ensure employees wear it; the selection must follow 29 CFR 1910.132 and 1910.133. See 1910.1047(g)(4), 1910.132 and 1910.133.

A written emergency plan must be developed for each workplace where an emergency is possible, and employees engaged in correcting emergency conditions must be equipped with respiratory protection required by paragraph (g) until the emergency is abated. See 1910.1047(h)(1)(i)-(ii) and 1910.1047(h)(1)(ii).

The written plan must include the elements in 29 CFR 1910.38 and 1910.39 (emergency action and fire prevention plans), and the employer must develop means to promptly alert potentially affected employees and immediately evacuate affected employees if an EtO emergency occurs. See 1910.1047(h)(1)(iii) and 1910.1047(h)(2).

The employer must institute medical surveillance for all employees who are or may be exposed to EtO at or above the action level for at least 30 days a year, regardless of respirator use. See 1910.1047(i)(1)(i)(A).

The employer must make medical examinations available: prior to assignment where exposure may be at/above the action level for ≥30 days/year; at least annually for employees exposed at/above the action level for ≥30 days in the past year; at termination of employment or reassignment away from such exposure; and as medically appropriate for employees exposed during an emergency. See 1910.1047(i)(2)(i)(A)-(D).

Medical exams must be provided as soon as possible when an employee notifies the employer they have signs or symptoms of possible EtO overexposure or requests medical advice about EtO effects on reproduction, and if the examining physician recommends more frequent exams the employer must provide them at those frequencies. See 1910.1047(i)(2)(i)(E)-(F).

Medical examinations required by the standard must include a medical and work history emphasizing pulmonary, hematologic, neurologic, reproductive, eye and skin symptoms; a physical exam focusing on those systems; and a complete blood count that includes at least white cell count (with differential), red cell count, hematocrit, and hemoglobin. See 1910.1047(i)(2)(ii)(A)(1)-(3).

All medical examinations and procedures must be performed by or under the supervision of a licensed physician and provided without cost to the employee, without loss of pay, and at a reasonable time and place. See 1910.1047(i)(2).

The employer must give the physician a copy of the EtO standard and Appendices A, B, and C; a description of the employee's duties related to exposure; the employee's representative or anticipated exposure level; a description of any personal protective and respiratory equipment used; and information from prior medical exams not otherwise available. See 1910.1047(i)(3).

The physician's written opinion must state the results of the medical exam, whether the employee has any medical conditions that increase risk from EtO exposure, any recommended limitations (including on PPE/respirator use), and confirm the employee was informed of results and required follow‑up; the employer must provide a copy of the physician's written opinion to the affected employee within 15 days of receipt. See 1910.1047(i)(4)(i)-(iii).

Chemical manufacturers, importers, distributors and employers must comply with all Hazard Communication Standard requirements for EtO, address hazards such as cancer, reproductive effects, mutagenicity, CNS effects, irritation and flammability, and include EtO in the workplace hazard communication program so employees have access to labels and safety data sheets and are trained accordingly. See 1910.1047(j)(1)(i)-(iii) and 1910.1200.

Employers must post and maintain legible signs marking regulated areas with the specific danger legend in 1910.1047(j)(2)(i)(A) (or the prior legend allowed before June 1, 2016), and must ensure labels are affixed to all containers of EtO that can cause exposures at/above the action level or above the excursion limit and that labels remain affixed when containers leave the workplace. See 1910.1047(j)(2)(ii)(A) and note the pesticide labeling exception in 1910.1047(j)(2)(ii)(C).

Employers must provide information and training to employees potentially exposed to EtO at or above the action level or above the excursion limit at the time of initial assignment and at least annually thereafter. See 1910.1047(j)(3)(i).

Yes — the content of medical exams or consultations provided under the standard may include pregnancy testing or laboratory fertility evaluation if requested by the employee and deemed appropriate by the examining physician. See 1910.1047(i)(2)(ii)(B).

Employers must inform employees about the listed items so workers know where EtO is present, what the rule requires, and what medical programs exist. Specifically, employers must tell affected employees:

• that they will receive an explanation of the requirements of 1910.1047 and its contents, including Appendices A and B;
• any operations in their work area where EtO is present;
• the location and availability of the written EtO final rule; and
• the medical surveillance program required by paragraph (i) of 1910.1047, with an explanation of the information in Appendix C.

These requirements come directly from 1910.1047(j)(3)(ii).

EtO training must cover specific detection, hazard, protective, and hazard communication topics so employees can recognize and avoid exposure. Training must include at least:

• Methods and observations to detect the presence or release of EtO (for example, employer monitoring or continuous monitors);
• The physical and health hazards of EtO;
• The measures employees can take to protect themselves, including the employer’s work practices, emergency procedures, and required personal protective equipment; and
• Details of the employer’s hazard communication program, including the labeling system and how to get and use hazard information.

These training topics are required by 1910.1047(j)(3)(iii).

Exposure measurement records must include specific sampling details and must be kept for at least 30 years. The record must include at least:

• The date of measurement;
• The operation being monitored;
• The sampling and analytical methods used and evidence of their accuracy;
• Number, duration, and results of samples taken;
• Type of protective devices worn, if any; and
• Name and exposure of the employees represented by the samples.

Employers must maintain these exposure records for at least thirty (30) years in accordance with 1910.1047(k)(2)(iii) and the employee-records rule at 29 CFR 1910.1020.

When an employer uses objective data to justify an exemption, they must create and keep a written objective-data record that documents the product, data source, testing, and how the operation is exempted—and keep it for as long as they rely on it. At minimum the record must include:

• The product qualifying for the exemption;
• The source of the objective data;
• The testing protocol, results of testing, and/or analysis for the release of EtO;
• A description of the operation exempted and explanation of how the data support the exemption; and
• Other relevant data about the operations, materials, processing, or exposures covered by the exemption.

The employer must maintain this objective-data record for the duration of the employer's reliance on that data per 1910.1047(k)(1)(iii).

Yes—employees or their designated representatives must be given an opportunity to observe EtO exposure monitoring, and if observing requires entering an area that needs protective clothing or equipment, the employer must provide and require use of that protective gear.

• 1910.1047(l)(1) requires employers to provide affected employees or their designated representatives an opportunity to observe any monitoring conducted under paragraph (d).
• 1910.1047(l)(2) says that when observation requires entering an area where protective clothing or equipment is required, the observer must be provided that clothing and equipment and must comply with the applicable safety procedures.

These provisions ensure transparency in monitoring while protecting observers from exposure.