What is ethylene oxide?
Ethylene oxide (EtO) is a flammable, colorless gas at
temperatures above 51.3 ºF (10.7 ºC) that smells like
ether at toxic levels. EtO is found in the production of
solvents, antifreeze, textiles, detergents, adhesives,
polyurethane foam, and pharmaceuticals. Smaller
amounts are present in fumigants, sterilants for spices
and cosmetics, as well as during hospital sterilization of
surgical equipment.
How can ethylene oxide harm workers?
In addition to eye pain and sore throat, exposure to
EtO can cause difficult breathing and blurred vision.
Exposure can also cause dizziness, nausea, headache,
convulsions, blisters and can result in vomiting and
coughing. Both human and animal studies show that
EtO is a carcinogen that may cause leukemia and other
cancers. EtO is also linked to spontaneous abortion,
genetic damage, nerve damage, peripheral paralysis,
muscle weakness, as well as impaired thinking and
memory. In liquid form, EtO can cause severe skin
irritation upon prolonged or confined contact.
What should employers know about
ethylene oxide?
Employee exposure is limited to one part EtO per
million parts of air (1 ppm) measured as an 8-hour
time-weighted average (TWA). Employee exposure may
not exceed the short-term excursion limit of 5 ppm EtO
averaged over any 15-minute sampling period. These
limits are called permissible exposure limits (PELs).
Most occupational exposures to EtO are covered by
the OSHA standard. The standard does not apply,
however, when employers can demonstrate that the
processing, use, or handling of products containing EtO
will not release airborne concentrations of EtO at or
above the standard’s action level of 0.5 ppm. The
action level is calculated as an 8-hour TWA and is the
threshold for increased compliance activities (e.g., air
monitoring, medical examinations, labeling, employee
information, and training).
For details of the requirements in OSHA’s EtO
standard for occupational exposures, see Title 29 of the
Code of Federal Regulations ( CFR) Part 1910.1047.
Note: Workplaces are exempt from this standard when
objective data shows that the processing, use, or
handling of products containing EtO cannot release
airborne concentrations of EtO at or above the action
level or in excess of the excursion limit during normal
conditions.
What must employers do when exposures
exceed the standard’s permissible exposure
limits?
If employee exposures exceed either the PEL or
the excursion limit, employers must take the following
actions:
¦ Use engineering controls and work practices to
control employee exposure.
¦ Establish and implement a written compliance
program to reduce exposures to or below the TWA
and exposure limit.
¦ Establish personal air monitoring as well as
information and training programs for employees
exposed to EtO at or above the action level or
above the excursion limit. Conduct training upon
initial job assignment and annually.
¦ Establish a regulated area wherever airborne
concentrations of EtO are expected to exceed the
8-hour TWA or the excursion limit.
¦ Establish a medical surveillance program for
employees exposed to EtO at concentrations above
the action level of 0.5 ppm, measured as an 8-hour
TWA, for more than 30 days per year.
¦ Place warning labels on all containers that might
cause employee exposures at or above the action
level or excursion limit.
¦ Remember that employee rotation is prohibited as a
means of compliance with the 8-hour TWA or
exposure limit.
¦ Select, provide, and maintain appropriate personal
protective equipment and ensure that employees use
it to prevent skin and eye contact.
When must employers require workers to
use respirators?
Employers must ensure that workers use
respirators to control EtO exposure in the following
circumstances:
¦ During installation or implementation of feasible
engineering controls and work practices;
¦ During maintenance, repair, and certain operations
when engineering and work practice controls are
not feasible;
¦ When engineering and work practice controls are
not currently available to reduce exposures to or
below the PEL; and
¦ During emergencies.
What are employers required to do
concerning exposure monitoring?
To help protect workers, employers must conduct
the following exposure monitoring:
¦ Initial monitoring to determine the airborne
concentrations of EtO that workers are exposed to
(representative sampling of employees’ exposures is
permitted).
¦ Periodic exposure monitoring if the airborne
concentration of EtO is at or above the action level
or above the 15-minute excursion limit.
¦ Additional monitoring if there has been a change in
workplace conditions, such as a change in the
2002
process or materials used, and if the change could
increase employee exposures.
Note: If the exposure level is maintained below the
action level, you may discontinue TWA monitoring until
there is a change in production, equipment, processes,
personnel, or control measures that may result in new
or additional exposure to EtO.
Employers must also do the following:
¦ Allow affected employees or their designated
representatives to observe the monitoring.
¦ Notify affected employees of the results of the
monitoring within 15 working days of receiving the
results.
Do all businesses where EtO is present need
medical surveillance programs?
Employers must implement a medical surveillance
program, conducted or supervised by a licensed
physician, for an employee under the following
circumstances:
¦ If the employee is assigned to an area where
exposure to EtO may be at or above the action level
for 30 days or more during the year.
¦ If the employee has been exposed to EtO in an
emergency situation.
What steps must employers take to
communicate with workers about EtO
exposure?
Employers must do the following to communicate
information to affected workers:
¦ Establish regulated areas where occupational
exposure to EtO exceeds the 8-hr TWA or
excursion limit, and clearly mark them to limit the
number of workers in the regulated area and to
allow only authorized persons to enter.
¦ Provide the signs and labels specified by the
standard clearly indicating EtO’s carcinogenic and
reproductive hazards in regulated areas.
¦ Train workers upon initial assignment and then
annually if they are at risk of exposure at or above
the action level or above the excursion limit.
¦ Maintain a material safety data sheet for EtO that
conforms to the provisions of OSHA’s hazard
communication standard, 29 CFR 1910.1200(g).
Are there any recordkeeping requirements
concerning employee exposures to EtO?
Employers are required to maintain the following
records relating to employee exposure to EtO:
¦ Retain employee exposure records for 30 years.
¦ Keep employee medical records for the duration of
employment plus 30 years.
¦ Keep records of objective data supporting any
claimed exemption from the requirements of the
OSHA standard.
What should employees do to protect
themselves from EtO exposure?
To protect against EtO exposure, follow these
safety precautions:
¦ Wear goggles and skin protection at all times in areas
where there is a risk of splashes from liquid EtO.
¦ Wear proper protective clothing and other approved
personal protective equipment when working with EtO.
¦ Discard clothing that has been degraded by EtO.
¦ See a doctor if you are exposed to EtO.
¦ Do not eat, drink, or smoke while working with EtO.
How can you get more information on
safety and health?
OSHA has various publications, standards, technical
assistance, and compliance tools to help you, and
offers extensive assistance through workplace
consultation, voluntary protection programs, grants,
strategic partnerships, state plans, training, and
education. OSHA’s Safety and Health Program
Management Guidelines ( Federal Register 54:3904-
3916, January 26, 1989) detail elements critical to
the development of a successful safety and health
management system. This and other information are
available on OSHA’s website.
¦ For one free copy of OSHA publications, send a selfaddressed
mailing label to OSHA Publications
Office, 200 Constitution Avenue N.W., N-3101,
Washington, DC 20210; or send a request to our
fax at (202) 693-2498, or call us at (202) 693-1888.
¦ To order OSHA publications online at www.osha.gov,
go to Publications and follow the instructions for
ordering.
¦ To file a complaint by phone, report an emergency,
or get OSHA advice, assistance, or products,
contact your nearest OSHA office under the “U.S.
Department of Labor” listing in your phone book, or
call toll-free at 800) 321-OSHA (6742). The
teletypewriter (TTY) number is (877) 889-5627.
¦ To file a complaint online or obtain more information
on OSHA federal and state programs, visit OSHA’s
website.
This is one in a series of informational fact sheets highlighting
OSHA programs, policies, or standards. It does
not impose any new compliance requirements. For a comprehensive
list of compliance requirements of OSHA
standards or regulations, refer to Title 29 of the Code of Federal
Regulations. This information will be made
available to sensory-impaired individuals upon request. The
voice phone is (202) 693-1999. See also OSHA’s
website at www.osha.gov.
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