www.osha.gov

Ethylene Oxide (EtO): 

Understanding OSHA’s Exposure

Monitoring Requirements

OSHA 3325-01N 2007
Employers are responsible for providing a safe and

healthful workplace for their employees. OSHA’s

role is to assure the safety and health of America’s

employees by setting and enforcing standards;

providing training, outreach and education; establishing partnerships; and encouraging continual

improvement in workplace safety and health. 

This handbook provides a general overview of a

particular topic related to OSHA standards. It does

not alter or determine compliance responsibilities in

OSHA standards or the Occupational Safety and

Health Act of 1970. Because interpretations and enforcement policy may change over time, you should

consult current OSHA administrative interpretations

and decisions by the Occupational Safety and Health

Review Commission and the Courts for additional

guidance on OSHA compliance requirements.

This publication is in the public domain and may be

reproduced, fully or partially, without permission.

Source credit is requested but not required.

This information is available to sensory impaired individuals upon request. Voice phone: (202) 693-1999;

teletypewriter (TTY) number: (877) 889-5627.

Edwin G. Foulke, Jr.

Assistant Secretary of Labor for

Occupational Safety and Health
U.S. Department of Labor

Occupational Safety and Health Administration

OSHA 3325-01N

2007

Ethylene Oxide (EtO): 

Understanding OSHA’s 

Exposure Monitoring Requirements

Making the Right Decisions – 

How to Comply with the EtO Standard
2

Contents

Purpose . . . 3

Background . . . 4

OSHA Requirement for Air Monitoring . . . 4 

Clarifying the Different Types of Exposure Monitoring . . . 4

Personal Monitoring . . . 5

Area Monitoring . . . 5

Leak Detection . . . 6

The OSHA Exposure Levels . . . 6

Monitoring Requirements . . . 9

Initial Monitoring . . . 9

Periodic Monitoring . . . 13

Actions Triggered by Air Sample Results . . . 15

Methods of Detecting Emergency EtO Releases . . . 17

Emergency Situations . . . 17

Emergency Plan for EtO . . . 17

Emergency Alert Provision . . . 18

How to Get Help with Air Monitoring . . . 19

Additional Sources of Information . . . 20

References . . . 21

OSHA Assistance . . . 23

OSHA Regional Offices . . . 28
Purpose

The purpose of this guidance document is to help employers

understand how to monitor the quality of the air in workplaces

where ethylene oxide (EtO) is processed, used, or handled. Air

monitoring is an important activity that can help alert employers

when unsafe levels of EtO are present in the air so that they can

take steps to reduce employee exposure. EtO can be used more

safely if appropriate precautions are taken and if equipment is

adequately designed and maintained. This document:

■ Clarifies the different types of EtO exposure monitoring,

■ Lists and explains the exposure levels used by OSHA,

■ Reviews the exposure monitoring requirements in OSHA’s EtO

rules, and

■ Outlines the monitoring decisions that the employer needs to

make when employees work in areas where EtO is present. 

All of the required actions presented in this document are

based on OSHA’s EtO standard (29 CFR 1910.1047). This guidance

document provides helpful suggestions for complying with

§1910.1047 as well.

3

This guidance document is not a standard or regulation, and it

creates no new legal obligations. The guidance document is

advisory in nature, informational in content, and is intended to

assist employers in providing a safe and healthful workplace.

The Occupational Safety and Health Act requires employers to

comply with hazard-specific safety and health standards

promulgated by OSHA or by a State with an OSHA-approved

State Plan. In addition, pursuant to Section 5(a)(1), the General

Duty Clause of the Act, employers must provide their employees

with a workplace free from recognized hazards likely to cause

death or serious physical harm. Employers can be cited for

violating the General Duty Clause if there is a recognized hazard

and they do not take reasonable steps to prevent or abate the

hazard. However, failure to implement these recommendations 

is not, in itself, a violation of the General Duty Clause. Citations

can only be based on standards, regulations, and the General

Duty Clause.
Background

EtO is used extensively by hospitals and other industries as a

sterilizing agent. EtO is a colorless, odorless gas which is both

flammable and highly reactive. Most importantly, you cannot smell

EtO until it reaches levels that can cause serious harm to human

health (NIOSH, 1989). Human and animal studies consistently show

that EtO can be hazardous to human health. Short-term exposures

to EtO can cause respiratory irritation and lung injury, shortness of

breath, headache, nausea, vomiting, and diarrhea. Long-term

exposure over many years may cause cancer, reproductive effects,

genetic changes, and damage to the nervous system (Lamontagne

et al., 1990).

OSHA Requirement for Air Monitoring 

The OSHA EtO standard requires employers to conduct personal

monitoring unless they are specifically exempt (see “Exemptions”

text box at page 10). This guidance document is intended to help

employers understand the difference between personal monitoring,

area monitoring, and leak detection and why area monitoring is

complementary to personal monitoring, but can never be used

instead of it.

Clarifying the Different Types 

of Exposure Monitoring 

There are three types of EtO monitoring available for determining

levels of EtO in a workplace: 1) personal monitoring, 2) area monitoring, and 3) leak detection (a special type of area monitoring).

However, personal monitoring is required to determine if there is

compliance with the exposure limits of the standard.

4
Personal Monitoring

Personal monitoring involves measuring a person’s exposure to

EtO by testing the air that the person (an employee) would breathe

regardless of where the person moves in the workplace. A sampling

device is attached to the shirt collar or as close as practical to the

nose and mouth of the employee in the employee’s “breathing

zone” – the hemisphere forward of the shoulders with a radius of

approximately six to nine inches – to test airborne EtO concentrations.

The device is worn for a specified period of time. During

personal monitoring for EtO, the sample is collected for 15 minutes

to test short-term exposure or for the length of a whole work shift

(typically 8 hours; see the text box “What if the Work Shift is Not

Exactly 8 Hours?” at page 8) to test for average exposures over the

course of a workday. These air samples will be referred to here as

15-minute samples and 8-hour samples.

Equipment used for personal monitoring typically includes a

“passive diffusion monitor” (a type of clip-on tag that collects EtO),

or alternatively a small air pump worn on the employee’s belt that

pulls a sample of air through a glass tube filled with a substance

that captures EtO. These samples typically must be sent to a

laboratory for analysis. The accuracy of any method depends to a

large degree upon the skills and experience of those who not only

collect the samples but also those who analyze the samples. 

After the samples have been analyzed, the employer must post

monitoring results within 15 days of receiving them, or notify

employees of the results in writing. The employer must also

mention the steps being taken to reduce employee exposures when

the monitoring results indicate that the time-weighted average or

excursion limit has been exceeded.

Area Monitoring

Area monitoring is used to show the levels of EtO throughout the

general working area and to identify problems and priorities.

Area samples should be taken close to a source of emission in

order to evaluate concentrations or the effectiveness of steps taken

to control exposure. Alternatively, area samples can be collected at

5
various places in the working area to assess how far EtO might

have spread. Equipment used for area monitoring is often mounted

on the wall or placed directly on equipment. The monitoring instrumentation can be similar to that used for personal monitoring, or it

can be of the “direct-reading” type, which gives an immediate

reading of the EtO level. When an employer uses direct reading

instruments, nothing needs to be sent to a laboratory but the

equipment must be calibrated periodically to ensure accuracy.

A wall-mounted emergency alert system used for area monitoring

is one example of a direct-reading area monitor (also see subsection

titled “Emergency Alert Provision” at page 18).

Leak Detection 

Employers, who are required to create a written compliance

program because their employees’ exposures are over the

permissible exposure limit, must also produce a schedule for

routine leak detection surveys. Some businesses that use EtO find it

helpful to test equipment such as sterilizers, pipes, tanks, and

fittings at least every two weeks to confirm that there are no leaks.

Portable EtO gas-detection meters are available to check for leaks

around equipment such as sterilizers, tanks, fittings, and pipes that

contain EtO. Leak testing is generally performed using hand-held

EtO detection meters (a type of portable direct-reading instrument). 

The OSHA Exposure Levels

The Federal OSHA regulation on EtO establishes certain allowable

exposure levels. This section will explain the terms, units, and

exposure levels that require action.

Units of Measure: Exposure levels are reported as concentrations

– the volume of EtO per volume of air. This is typically expressed

as “parts per million” (also called “ppm”). One part per million

means that there is one part of EtO in every million parts of air

sampled. Alternatively, the concentration of EtO can also be

reported using metric units, in milligrams of EtO per cubic meter

6
of air (mg/m3

). It is important to compare only exposure values

that have the same units of measure. For example, only compare

exposure results reported as ppm to the OSHA levels for EtO

reported in ppm.

Action Level: The “action level” is the 8-hour exposure level

that triggers certain actions under OSHA’s EtO standard. If an

employee’s 8-hour sample result is equal to or greater than the

action level, the employer must start certain required activities

such as exposure monitoring and medical surveillance.

The action level for EtO is 0.5 ppm (which equals 0.9 mg/m3

).

Actions an employer must take if the personal monitoring test

result is greater than, or equal to, the “action level” are outlined in

the subsection titled “Actions Triggered by Air Sample Results” at

page 15.

Permissible Exposure Limit (PEL): This is the exposure level of

EtO above which no employees may be exposed to under

normal workplace conditions. You should become familiar with

two PELs; one for 8-hour samples and one for 15-minute

samples.

Eight-Hour Time-Weighted Average (8-hour TWA) — This is

an 8-hour (or full work shift) sample that represents the

maximum average EtO levels that an employee should be

exposed to. 

The 8-hour PEL for EtO is 1 ppm (which equals 1.8 mg/m3

).

Excursion Limit (15-minute) — This is a 15-minute (shortterm) sample that represents the maximum EtO exposure

level that an employee may be exposed to for a short period

of time. 

Rotating employees to different workstations so that they are

not exposed to higher EtO levels is not an accepted way of

meeting the 8-hour TWA or the Excursion Limit requirement.

The 15-minute Excursion Limit for EtO is 5 ppm (equal to 9

mg/m3).

Both types of samples are important because, taken together, they

help employers protect employees over the range of exposure

7
conditions that employees are likely to experience. Actions that

an employer must take if these PELs are exceeded are outlined in

Tables 3 and 4 at pages 15-17.

What if the Work Shift is Not Exactly 8 Hours?

When you collect an 8-hour sample, OSHA expects you to

collect the sample for the length of the whole work shift, no

matter how long it is. The shift might be more or less than 8

hours. Although not every sample will be exactly 8 hours, the

OSHA action level and 8-hour permissible exposure limit

must only be compared to an 8-hour sample result. 

To avoid confusion caused by samples collected for more or

less time, OSHA allows you to use a simple equation that

converts any full-shift sample result to an 8-hour equivalent

result (also called an 8-hour time-weighted average or an 8-

hour TWA result). 

Equation:

C8 = CA(TA)/T8

TA = The actual time during which your sample was collected (in minutes).

CA = The actual result (concentration) for your sample (in ppm).

T8 = 480 minutes (this is the number of minutes in 8 hours).

C8 = The 8-hour equivalent result for your sample (in ppm).

Fortunately, most analytical laboratories will do the calculation

for you. Ask the laboratory to “Report the full-shift results as

8-hour time-weighted averages (or 8-hour TWAs).” You do

not need to make this arrangement for 15-minute samples,

which should always be collected for exactly 15 minutes. 

When exposure levels are high, it may be necessary to collect

a series of mid-length samples (for example, 1-2 hours each)

instead of a single 8-hour sample for an employee. In this

case, ask the laboratory to combine all the results from one

employee to create a single 8-hour TWA result.

8
Monitoring Requirements

■ What types of monitoring are required to be in compliance

with OSHA’s EtO standard?

The OSHA EtO standard requires that each employer whose

workplace does not meet the “exemption” clause,

§1910.1047(a)(2), must perform personal monitoring to show

whether EtO exposures are exceeding the 8-hour and/or the 15-

minute PEL. The OSHA standard requires that these samples be

“representative” of EtO exposures (see “Criteria for Using

Results from Similar Work Conditions” text box, at page 11). There

are two types of monitoring requirements: initial and periodic.

Initial Monitoring

■ Do I need to collect initial EtO samples?

Yes. If you are not exempt (see “Exemptions” text box at page 10)

and there is reason to believe that exposure levels may equal or be

above the action level under “expected conditions of operation,”

then you are required to conduct personal EtO monitoring to

accurately measure the airborne concentrations of EtO. Most

employers should assume that exposure levels may reach or

exceed the action level and that they must conduct exposure

monitoring: 1) if their business involves processing, using, or

handling products containing EtO; 2) if they are not exempt as

described in the Exemption text box; and 3) if they have never

conducted personal monitoring. 

This level of caution is important because accidental releases of

EtO may occur from several sources, including leaking cartridges,

sterilizer discharge lines and leaks, or routine changing of EtO

supply cylinders. A relatively small quantity of EtO released into

an average office-sized space can result in concentrations that

are many times above the action level or PEL (NIOSH, 1989;

Lamontagne and Kelsey 1998). If there are special circumstances

that would suggest that monitoring is not required for your

workplace and you need further clarification, we encourage you to

9
contact your local area OSHA office. Locate your local area OSHA

office by phone at 1-800-321-OSHA or online at http://www.osha.

gov/html/ RAmap.html.

When carrying out initial monitoring, you must collect both 8-

hour samples (full work shift) and 15-minute samples (short-term).

At least one sample of each type is required for:

• Each work shift, 

• Each job classification, and 

• In each work area of the workplace.

Exemptions

Is Monitoring Always Required? 

No. An employer is exempt from the standard and, therefore,

is not required to conduct employee exposure monitoring if

“objective data” demonstrates the processing, use, or

handling of products containing EtO are not capable of

releasing EtO in concentrations at or above the OSHA action

level or in excess of the excursion limit under expected

conditions that will cause the greatest possible release. 

The objective data might include specific information

generated by an individual employer or obtained from

chemical manufacturers, industry studies, or trade associations that documents why your facility’s processing, use, or

handling of EtO would not result in workplace concentrations

exceeding the action level or excursion limit.

Objective data records must be kept as long as the employer

relies on the data to demonstrate that monitoring is not

required. The types of information that should be kept include: 

• The source of the objective data,

• The testing protocol, results, and/or analysis of data,

• The exempted operation and corresponding information

supporting the exemption, and

• Any other data relevant to the operations, materials, processes,

or employee exposures covered by the exemption.

10
■ Do I need to collect initial personal monitoring samples for

every single employee, on every work shift?

No. But you do need to determine the exposure level of every

employee. If you have only one employee, or just a few who all do

different jobs, you need to collect personal samples for each

employee. However, if you have two or more employees who do

the same job, you may be able to collect personal samples for one

of these employees and use the results to document exposure

levels for all of these employees. This is known as representative

sampling. To decide whether the results for one employee will

represent the EtO exposure of other employees in the group, you

must evaluate certain criteria (see “Criteria for Using Results from

Similar Work Conditions” text box). 

If the answer is “no” to any of the questions, you probably need

to compare a smaller and more similar group of employees, or

conduct individual personal monitoring for each employee. If the

answer to all of these questions is “yes,” you may use the results

from one or more employee to represent the exposure of other

employees in the group. However, you must select the employee

who is likely to have the highest EtO exposure (due to slight

variations in work area, work practices, or experience). 

Criteria for Using Results from Similar Work Conditions

• Do the employees do the same work?

• Are their working conditions similar (for example, do the

employees use similar equipment and EtO products?)

• Do the employees have similar work practices, with similar

EtO control measures?

• Do they work in the same area or in areas with similar air

movement patterns?

• Do the employees use the same EtO product for the same

amount of time during their shifts?

• Do the employees work the same distance from possible

sources of EtO?

11
You must also keep a record stating your reasons for selecting

an employee from one work shift to represent employees on

another shift. One way to document the similarity of shifts is by

sampling employees on each shift one time to show that the

employee exposures are the same on each shift. If the exposures

are the same, you can conduct future required periodic sampling

on a single shift and consider it representative of all shifts. You may

use this option with 8-hour samples and with 15-minute samples. 

■ Am I permitted to use results of air samples collected at another

time or at a different location from my initial monitoring results?

Yes, but the work conditions must have been similar on the two

dates, or at the two locations. The text box “Criteria for Using

Results from Similar Work Conditions” also applies in this situation.

Again, if the answer is “no” to one or more of the questions, it is

likely that you must conduct initial monitoring. If the answer is

“yes,” then OSHA allows you to meet the initial monitoring requirements by using personal monitoring results collected for other

employees at an earlier date or at a different location in the

workplace. Be sure to keep a document explaining why it was

appropriate to use those results.

■ Which 15-minute period should I monitor? 

You must collect a 15-minute air sample during the portion of the

work shift when you think that the employee’s EtO exposure will be

the highest. You may need to collect several 15-minute samples

during the same shift (see text box “Why Is It So Important to

Collect 15-Minute Samples?”).

Why Is It So Important to Collect 15-Minute Samples?

Research suggests that EtO exposures above the 15-minute

OSHA PEL continue to occur in workplaces that are involved

in processing, using, or handling products containing EtO.

Recent studies have also shown that personal monitoring

activities often fail to detect accidental exposures during EtO 

12
leaks and spills (Lamontagne et al., 2004; Lamontagne and

Kelsey 1998). Therefore, it is important to carefully consider 

the types of activities for which 15-minute monitoring are

most useful. The following examples should provide some

guidance:

• A common situation in which accidental exposures to EtO 

might occur involves changing EtO supply cylinders.

Consider collecting 15-minute personal samples while the

employees being sampled are replacing EtO cylinders.

• Employees who work directly with, or in close proximity to,

EtO sterilizers or similar equipment should be monitored

frequently for short-term (i.e., 15-minute) exposures to

EtO at the times when they are most likely to experience

exposure (such as when the employee opens the door at

the end of the cycle, or while EtO is being pumped in or

out of the equipment).

Periodic Monitoring

■ Do I need to repeat the EtO personal monitoring and, if so, what

is the monitoring schedule?

The answer depends on the results of initial personal monitoring

for EtO. Under certain situations, a long-term schedule for personal

monitoring for EtO must be established. Tables 1 and 2 provide the

“periodic monitoring” schedule required by the EtO standard. The

personal monitoring results might also trigger other requirements

that are listed in Tables 3 and 4, which appear later in this guidance

document.

Table 1 – Schedule for OSHA Exposure Monitoring

If your initial employee monitoring 

results... Then...

...show that employee exposure is Discontinue monitoring for only those

below the 8-hour action level, employees whose exposures are 

represented by the initial monitoring.

13
14

If your initial employee monitoring 

results... Then...

...are between the 8-hour action level Conduct additional 8-hour personal

(0.5 ppm) and the 8-hour permissible exposure monitoring at least every 

exposure limit (PEL) of 1 ppm 6 months.

(including the value 0.5 ppm),

...are above the 8-hour PEL of 1 ppm Conduct additional personal exposure

or above the 15-minute PEL of 5 ppm, monitoring (either 8-hour or 15-

minute, depending on the sample type

that initially exceeded the limit) at 

least every 3 months.

Table 2 – Requirements for Discontinuing Monitoring

If your periodic employee monitoring 

results had been above the PEL 

(either the 8-hour TWA or the 15-

minute excursion limit) and... Then...

...are now between the 8-hour action You can decrease the 8-hour personal 

level (0.5 ppm) and the 8-hour PEL of monitoring frequency from every 3 

1 ppm (including the value 0.5 ppm) months to every 6 months. Note: if 

for two consecutive tests (these 15-minute exposures exceed the 

samples must be collected at least excursion limit of 5 ppm, you will still 

7 days apart, but no more than 3 need to conduct the 15-minute 

months apart), (excursion limit) monitoring at least 

every 3 months.

...are now less than the 8-hour action You are no longer required to conduct 

level (0.5 ppm) for two consecutive periodic personal monitoring unless a 

tests (the samples must be collected change in the workplace makes 

at least 7 days apart, but no more additional monitoring necessary.

than 3 months apart),

...now indicate that employee You may discontinue 15-minute 

exposures are at or below the 15- (excursion limit) monitoring for those 

minute PEL of 5 ppm (the excursion employees whose exposures are 

limit) for two consecutive tests (the represented by the initial monitoring.

samples must be collected at least 

7 days apart, but no more than 3 

months apart),

For definitions of OSHA Exposure Levels, see page 6.
■ When must I resume air monitoring? 

You must start monitoring again whenever there is a change that

may result in new or additional exposures to EtO. Examples of

changes that should be evaluated to determine if they may result in

new or additional exposures and, therefore, would trigger resuming

EtO sampling include:

• Changing EtO process equipment or increasing the volume

of EtO used,

• Modifying the exhaust ventilation system,

• Hiring new or inexperienced employees, and

• Changing work practices. 

You also must resume sampling any time that you have a

reason to suspect that such a change may result in new or

additional exposures.

Actions Triggered by Air Sample Results

■ I received air sampling results; now what do I do?

Tables 3 and 4 provide the lists of actions you need to take as a

result of EtO monitoring results that exceed specific levels. These

actions are based on the OSHA action level and/or PELs (8-hour

and/or 15-minute samples). 

Table 3 – Actions Triggered by Air Sample Results

Result interpretation: 8-hour sample 8-hour sample 15-minute Other OSHA 

is equal to or is above sample is Standards 

above Action Permissible above that Apply**

Level Level Excursion 

Limit

Result value: 0.5 ppm or Above 1 ppm Above 5 ppm

greater

Action Triggered by Monitoring Results

Provide medical Yes Yes Not required 1910.1020

surveillance 

(if employee’s 

exposure is more 

than 30 days per 

year)*

Provide information Yes Yes Yes –

and training

15
Establish a Not required Yes Yes, also if –

regulated area expected to 

exceed this 

level

Take steps to reduce Not required Yes Yes –

exposure levels with 

engineering controls 

or other methods

Develop and put Not required Yes Yes --

into action a written 

compliance program 

for reducing 

exposure and 

establishing a 

schedule for periodic 

leak detection

Provide respirators Not required Yes Yes 1910.134

Ensure that caution Yes Yes Yes 1910.1200

labels are fixed to 

containers (also 

when container 

contents are capable 

of causing or can be 

reasonably foreseen 

to cause these 

exposure levels)

Establish periodic Yes, at least Yes, at least Yes, at least 1910.1020

air monitoring every 6 every 3 every 3

programs months months months

* Medical examinations are also required if there is an exposure related to 

an emergency situation.

** For information on OSHA standards that apply, see the text box titled

“Important References to OSHA Standards”.

Table 4 – Actions Triggered by the Air Sampling Process

Other Actions Triggered by When to Take Action Other OSHA 

Air Monitoring Standards

that Apply*

Post monitoring results Any time that samples are 1910.1020

within 15 days of receiving collected – regardless of the 

them, or give employees the results

written results. Mention 

steps being taken to reduce 

exposures.

Maintain records of Any time that samples are 1910.1020

monitoring for 30 years collected – regardless of the 

results

16
Allow employees or their Any time that samples are

representatives to observe collected –

air monitoring 

* For information on OSHA standards that apply, see the text box titled

“Important References to OSHA Standards” at page 22.

Methods of Detecting Emergency 

EtO Releases

There are a number of options available on how to monitor and test

for emergency leaks of EtO. These methods may be appropriate in

addition to, but not instead of, personal air monitoring. They

cannot be used as a substitute for personal monitoring to satisfy

OSHA personal air monitoring requirements.

Emergency Situations

The OSHA EtO standard requires that a written plan for each

workplace be developed for emergency situations. (See also

§1910.38 Emergency Action Plans and §1910.39 Fire Prevention

Plans.)

Emergency Plan for EtO

The following are some simple steps to ensure that your workplace

meets the emergency plan requirements in OSHA’s EtO standard:

■ For employers with more than 10 employees, the emergency

plan must be in writing and available to employees. If you have

10 or fewer employees, the plan may be communicated verbally

to employees.

■ The plan must include procedures for emergency evacuation,

including type of evacuation and exit route assignments (refer to

OSHA’s standard for “Emergency Action Plans”, listed in the text

box on Important References to OSHA Standards at page 22).

Although not specifically required, you can be proactive in

17
18

emergency planning preparations by conducting employee

evacuation drills for potential EtO emergencies.

■ You must have a system for alerting employees to emergency

EtO exposures. You do have the flexibility to choose any

effective method of alerting employees to potential EtO releases

that could result in harmful exposures. 

■ The plan must specifically provide that employees engaged

in correcting emergency conditions shall be equipped with

respiratory protection as required by §1910.1047(g) until the

emergency is abated and must be implemented in accordance

with §1910.134, Respiratory Protection.

Emergency Alert Provision

The emergency alert provision of OSHA’s EtO standard allows

employers to choose the most effective method of alerting

employees across industries. As part of the emergency plan, you

must develop a system for alerting your employees. The precise

type of alert system is not specified in the OSHA EtO standard.

OSHA considers the following alert methods acceptable for an

EtO monitoring system:

■ A bell or other alarm system:

A bell or alarm system must

have a distinctive signal to

alert employees to an EtO

leak (refer to §1910.165,

Employee Alarm Systems).

■ A voice-activated system:

Like other alarm types, this

system must have a

distinctive signal to alert

employees to an EtO leak.

■ Voice communications: For

those employers with 10 or

fewer employees in a

particular workplace, the

requirements under

Monitoring Systems

Alarm systems basically function as a

monitor to test the surrounding air for

EtO levels. 

To monitor EtO levels near sterilizers,

some employers find it convenient to

install a wall-mounted, or equipmentmounted system.

Commercially available alarms that

monitor EtO levels and use both visual

and sound alarms can alert employees

in noisy or crowded areas when the

level of EtO is higher than it should be. 

More information about some specific

types of monitoring devices can be

found at page 20 under “Additional

Sources of Information”. 
19

“Employee alarm systems” states that direct voice communication is an acceptable method of alerting employees, providing

that all employees at their respective workstations can clearly

hear the person’s voice. For workplaces with more than 10

employees, simple voice communication is not acceptable.

■ Is there a specific EtO level that I should use to trigger an alert?

OSHA has not established an “alert” level; you should choose an

alert trigger level that is appropriate for your workplace. When

evaluating alarms, it is important to remember that the alarm’s

purpose is to alert employees to unintended and hazardous EtO

releases, rather than to average concentrations measured over an

8-hour work shift. It is not necessary to base the EtO alarm trigger

specifically on the OSHA action level (0.5 ppm) or permissible

exposure limits for 8 hours (1 ppm) or 15 minutes (5 ppm). 

You should also be aware that there is a large range in the cost

and sensitivity of commercially available monitors. Some systems

alert employees to EtO levels greater than 20 ppm, while other

highly sensitive monitoring devices can trigger an alarm at much

lower levels, such as 1 ppm or even lower (NIOSH, 1989). 

Researchers suggest that alarms that alert employees to

accidental EtO spills or leaks can be reasonably set to levels of 

20 ppm without compromising employee health and safety

(Lamontagne and Kelsey, 1998).

How to Get Help with Air Monitoring

If you need help with air monitoring, contact the OSHA On-Site

Consultation Services office for your area which can be searched by

location, at http://www.osha.gov/dcsp/smallbusiness/consult_

directory.html. This service is often free of charge to employers.

Alternatively, you can hire an “industrial hygienist” consultant who

specializes in workplace air monitoring. These consultants are often

listed in the telephone directory under the headings for environmental monitoring or assessment. The American Industrial Hygiene
Association (AIHA) website also maintains a list of industrial

hygiene consultants which can be searched by location, at

www.aiha.org.

Laboratories provide analytical services and sometimes advise

employers on selecting air sampling equipment and test media.

Some laboratories provide the media or loan the equipment as part

of the analysis package. Laboratories that analyze workplace air

samples are typically listed in the telephone directory (environmental – analysis) and also on the AIHA website. When selecting a

laboratory, one important question to ask is “Does your laboratory

meet the accuracy requirements of OSHA’s Ethylene Oxide

standard?” OSHA’s accuracy requirements can be found in

§1910.1047(d)(6).

Additional Sources of Information 

U.S. Navy web link that provides information about selecting EtO

sterilizer alarm systems

http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/3_VII_2.html

Ethylene Oxide (EtO) Information

Environmental Monitoring Technology (EMT). EMT provides health

and safety services to hospitals, clinics, laboratories, surgery

centers, nursing homes, and general industry.

http://www.emt-online.com/LinksEto.htm

OSHA Fact Sheet on Ethylene Oxide (2002)

http://www.osha.gov/OshDoc/data_General_Facts/ethylene-oxidefactsheet.pdf

Ethylene Oxide Awareness Training

Albert Einstein College of Medicine, Department of Environmental

Health and Safety

http://www.aecom.yu.edu/ehs/osha%20regulated/Ethylene%20

Oxide.pdf

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21

EZ Facts Safety On-line, Ethylene Oxide Fact Sheet (2003)

http://www.labsafety.com/refinfo/printpage.htm?page=/refinfo/

ezfacts/ezf176.htm

References

Lamontagne AD, et al. 1990. Ethylene Oxide Health & Safety

Manual: Training and Reference Materials on the Safe Use of

Ethylene Oxide in Sterilizing Equipment. Second Edition. (OSHA

Docket H200C, exhibit 2-9-L).

Lamontagne, AD, and Kelsey, MD. 1998. OSHA’s Renewed Mandate

for Regulatory Flexibility: In Support of the 1984 Ethylene Oxide

Standard. American Journal of Industrial Medicine. 34: 95-104. 

Lamontagne, AD, Oakes, JM, and Lopez, RN. 2004. Long-Term

Ethylene Oxide Exposure Trends in U.S. Hospitals: Relationship

with OSHA Regulatory and Enforcement Actions. American Journal

of Public Health. 94: (9), 1614-1619.

NIOSH. 1989. Technical Report: Control Technology for Ethylene

Oxide Sterilization in Hospitals. Report No. 89-120. National Institute

for Occupational Safety and Health. 89-120.pdf (179 pages, 4,133K).
Important References to OSHA Standards

OSHA, Ethylene Oxide Standard: 29 CFR 1910.1047

This is the standard that lists the OSHA requirements for EtO.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=10070

OSHA, Emergency Action Plans: 29 CFR 1910.38 

This standard requires employers to create an emergency action plan. It

also lists details that must be considered in the emergency action plan.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=9726

OSHA, Respiratory Protection Standard: 29 CFR 1910.134

This standard requires employers to have a written respiratory

protection program and a designated administrator for the program.

The respiratory protection program must state how respirators will be

selected, maintained, and cleaned. Employees must be medically

qualified, trained, and fit tested before they wear a respirator.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=12716

OSHA Employee Alarm Systems: 29 CFR 1910.165 

This standard lists maintenance, testing and inspection requirements

for emergency employee alarm systems.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=9819

OSHA, Access to Employee Exposure and Medical Records: 29 CFR

1910.1020

This standard requires employers to maintain exposure and medical

records for 30 years. It also sets requirements for keeping medical

records confidential.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=10027

OSHA, Hazard Communication Standard: 29 CFR 1910.1200

This standard requires employers to inform employees of the hazards

associated with products they might be exposed to in the workplace.

Employers must label containers and maintain material safety data

sheets (MSDSs).

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=

STANDARDS&p_id=10099

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OSHA Assistance

OSHA can provide extensive help through a variety of programs,

including technical assistance about effective safety and health

programs, state plans, workplace consultations, voluntary protection programs, strategic partnerships, training and education,

and more. An overall commitment to workplace safety and health

can add value to your business, to your workplace and to your life.

Safety and Health Program Management Guidelines

Effective management of employee safety and health protection is

a decisive factor in reducing the extent and severity of work-related

injuries and illnesses and their related costs. In fact, an effective

safety and health program forms the basis of good employee

protection and can save time and money (about $4 for every

dollar spent), increase productivity, and reduce employee

injuries, illnesses and related workers’ compensation costs.

To assist employers and employees in developing effective

safety and health programs, OSHA published recommended Safety

and Health Program Management Guidelines (54 Federal Register

(16): 3904-3916, January 26, 1989). These voluntary guidelines

apply to all places of employment covered by OSHA.

The guidelines identify four general elements critical to the

development of a successful safety and health management

program:

■ Management leadership and employee involvement.

■ Work analysis.

■ Hazard prevention and control.

■ Safety and health training.

The guidelines recommend specific actions, under each of 

these general elements, to achieve an effective safety and health

program. The Federal Register notice is available online at

www.osha.gov. 

State Programs

The Occupational Safety and Health Act of 1970 (OSH Act) encourages states to develop and operate their own job safety and

23
health plans. OSHA approves and monitors these plans. Twentyfour states, Puerto Rico and the Virgin Islands currently operate

approved state plans: 22 cover both private and public (state and

local government) employment; Connecticut, New Jersey, New

York and the Virgin Islands cover the public sector only. States and

territories with their own OSHA-approved occupational safety and

health plans must adopt standards identical to, or at least as

effective as, the Federal standards. 

Consultation Services

Consultation assistance is available on request to employers who

want help in establishing and maintaining a safe and healthful

workplace. Largely funded by OSHA, the service is provided at no

cost to the employer. Primarily developed for smaller employers

with more hazardous operations, the consultation service is delivered by state governments employing professional safety and

health consultants. Comprehensive assistance includes an appraisal

of all mechanical systems, work practices and occupational safety

and health hazards of the workplace and all aspects of the employer’s present job safety and health program. In addition, the

service offers assistance to employers in developing and implementing an effective safety and health program. No penalties are

proposed or citations issued for hazards identified by the consultant. OSHA provides consultation assistance to the employer

with the assurance that his or her name and firm and any information about the workplace will not be routinely reported to OSHA

enforcement staff.

Under the consultation program, certain exemplary employers

may request participation in OSHA’s Safety and Health

Achievement Recognition Program (SHARP). Eligibility for participation in SHARP includes receiving a comprehensive consultation

visit, demonstrating exemplary achievements in workplace safety

and health by abating all identified hazards and developing an

excellent safety and health program.

Employers accepted into SHARP may receive an exemption

from programmed inspections (not complaint or accident investigation inspections) for a period of one year. For more information

concerning consultation assistance, see the OSHA website at

www.osha.gov.

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Voluntary Protection Programs (VPP)

Voluntary Protection Programs and on-site consultation services,

when coupled with an effective enforcement program, expand

employee protection to help meet the goals of the OSH Act. The 

three levels of VPP are Star, Merit, and Star Demonstration

designed to recognize outstanding achievements by companies

that have successfully incorporated comprehensive safety and

health programs into their total management system. The VPPs

motivate others to achieve excellent safety and health results in the

same outstanding way as they establish a cooperative relationship

between employers, employees and OSHA.

For additional information on VPP and how to apply, contact the

OSHA regional offices listed at the end of this publication.

Strategic Partnership Program

OSHA’s Strategic Partnership Program, the newest member of

OSHA’s cooperative programs, helps encourage, assist and

recognize the efforts of partners to eliminate serious workplace

hazards and achieve a high level of employee safety and health.

Whereas OSHA’s Consultation Program and VPP entail one-on-one

relationships between OSHA and individual worksites, most

strategic partnerships seek to have a broader impact by building

cooperative relationships with groups of employers and employees. These partnerships are voluntary, cooperative relationships between OSHA, employers, employee representatives and

others (e.g., labor unions, trade and professional associations, 

universities and other government agencies). 

For more information on this and other cooperative programs,

contact your nearest OSHA office, or visit OSHA’s website at

www.osha.gov.

Alliance Program

The Alliance Program enables organizations committed to workplace safety and health to collaborate with OSHA to prevent injuries

and illnesses in the workplace. OSHA and the Alliance participants

work together to reach out to, educate and lead the nation’s

employers and their employees in improving and advancing

workplace safety and health. 

25
Groups that can form an Alliance with OSHA include employers,

labor unions, trade or professional groups, educational institutions

and government agencies. In some cases, organizations may be

building on existing relationships with OSHA that were developed

through other cooperative programs. 

There are few formal program requirements for Alliances and

the agreements do not include an enforcement component. However, OSHA and the participating organizations must define, implement and meet a set of short- and long-term goals that fall into

three categories: training and education; outreach and communication; and promoting the national dialogue on workplace safety and

health. 

OSHA Training and Education

OSHA area offices offer a variety of information services, such as

compliance assistance, technical advice, publications, audiovisual

aids and speakers for special engagements. OSHA’s Training

Institute in Arlington Heights, IL, provides basic and advanced

courses in safety and health for Federal and state compliance

officers, state consultants, Federal agency personnel, and private

sector employers, employees and their representatives.

The OSHA Training Institute also has established OSHA Training

Institute Education Centers to address the increased demand for its

courses from the private sector and from other Federal agencies.

These centers are nonprofit colleges, universities and other organizations that have been selected after a competition for participation

in the program.

OSHA also provides funds to nonprofit organizations, through

grants, to conduct workplace training and education in subjects

where OSHA believes there is a lack of workplace training. Grants

are awarded annually. Grant recipients are expected to contribute

20 percent of the total grant cost.

For more information on grants, training and education, contact

the OSHA Training Institute, Office of Training and Education, 2020

South Arlington Heights Road, Arlington Heights, IL 60005, (847)

297-4810 or see “Training” on OSHA’s website at www.osha.gov.

For further information on any OSHA program, contact your

nearest OSHA area or regional office listed at the end of this

publication.

26
Information Available Electronically

OSHA has a variety of materials and tools available on its website

at www.osha.gov. These include eTools such as Expert Advisors,

Electronic Compliance Assistance Tools (e-cats), Technical Links;

regulations, directives and publications; videos and other information

for employers and employees. OSHA’s software programs and

compliance assistance tools walk you through challenging safety

and health issues and common problems to find the best solutions

for your workplace.

A wide variety of OSHA materials, including standards, interpretations, directives, and more, can be purchased on CD-ROM from

the U.S. Government Printing Office, Superintendent of Documents,

phone toll-free (866) 512-1800.

OSHA Publications

OSHA has an extensive publications program. For a listing of free

or sales items, visit OSHA’s website at www.osha.gov or contact the

OSHA Publications Office, U.S. Department of Labor, 200

Constitution Avenue, NW, N-3101, Washington, DC 20210.

Telephone (202) 693-1888 or fax to (202) 693-2498. 

Contacting OSHA

To report an emergency, file a complaint or seek OSHA advice,

assistance or products, call (800) 321-OSHA or contact your nearest

OSHA regional or area office listed at the end of this publication.

The teletypewriter (TTY) number is (877) 889-5627.

Written correspondence can be mailed to the nearest OSHA

Regional or Area Office listed at the end of this publication or to

OSHA’s national office at: U.S. Department of Labor, Occupational

Safety and Health Administration, 200 Constitution Avenue, N.W.,

Washington, DC 20210.

By visiting OSHA’s website at www.osha.gov, you can also:

■ file a complaint online,

■ submit general inquiries about workplace safety and health electronically, and

■ find more information about OSHA and occupational safety 

and health.

27
OSHA Regional Offices

* These states and territories operate their own OSHA-approved job

safety and health programs (Connecticut, New Jersey, New York and the

Virgin Islands plans cover public employees only). States with approved

programs must have standards that are identical to, or at least as effective

as, the Federal standards.

Note: To get contact information for OSHA Area Offices, OSHAapproved State Plans and OSHA Consultation Projects, please visit us

online at www.osha.gov or call us at 1-800-321-OSHA.

Region I

(CT,* ME, MA, NH, RI, VT*) 

JFK Federal Building, Room E340

Boston, MA 02203

(617) 565-9860

Region II

(NJ,* NY,* PR,* VI*)

201 Varick Street, Room 670

New York, NY 10014

(212) 337-2378

Region III

(DE, DC, MD,* PA, VA,* WV)

The Curtis Center

170 S. Independence Mall West

Suite 740 West

Philadelphia, PA 19106-3309

(215) 861-4900

Region IV 

(AL, FL, GA, KY,* MS, NC,* SC,* TN*)

61 Forsyth Street, SW

Room 6T50

Atlanta, GA 30303

(404) 562-2300

Region V

(IL, IN,* MI,* MN,* OH, WI)

230 South Dearborn Street 

Room 3244

Chicago, IL 60604

(312) 353-2220

Region VI

(AR, LA, NM,* OK, TX)

525 Griffin Street, Room 602

Dallas, TX 75202

(214) 767-4731 or 4736 x224

Region VII

(IA,* KS, MO, NE)

City Center Square

1100 Main Street, Suite 800

Kansas City, MO 64105

(816) 426-5861

Region VIII

(CO, MT, ND, SD, UT,* WY*)

1999 Broadway, Suite 1690

PO Box 46550

Denver, CO 80202-5716

(720) 264-6550

Region IX 

(American Samoa, AZ,* CA,* HI,* NV,*

Northern Mariana Islands)

71 Stevenson Street, Room 420

San Francisco, CA 94105

(415) 975-4310

Region X

(AK,* ID, OR,* WA*)

1111 Third Avenue, Suite 715

Seattle, WA 98101-3212

(206) 553-5930

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