ETHYLENE OXIDE
STANDARD OPERATING PROCEDURE
Type of SOP:
Process
Hazardous Chemical
Hazard Class
To customize this SOP, add lab-specific information to the sections below marked in
RED, as applicable. Completion of the last section (“Lab-Specific Information”) is
required. Also, any of the content below may be amended with lab-specific information
to enhance worker safety as desired.
HAZARD OVERVIEW
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Extremely flammable
Acutely toxic and corrosive to tissue
Carcinogenic
Ethylene oxide, or oxirane, is an extremely flammable gas at room temperature (flash
point = -20 oC, flammable range in air 2.6%-100%). Dissolved in water, it remains
flammable at a concentration of 4% by volume, making it a serious explosion hazard if
poured down the drain.
Ethylene oxide can self-polymerize violently upon exposure to heat, acid, or base.
Violent reaction can occur with exposure to copper or its alloys, and rust. The heat of
burning in a fire may cause the additional hazard of self-polymerization, resulting in
explosion.
Ethylene oxide is classified as Category 1B carcinogen.
Ethylene oxide is acutely toxic if inhaled, causing mucous membrane and respiratory
irritation, headache, vomiting, cyanosis, drowsiness, weakness, incoordination, CNS
depression, lachrymation, and labored breathing. Delayed effects may include edema
of the lungs, paralysis, convulsions and death. Its odor threshold is > 250 ppm, while its
permissible exposure limit is 1 ppm, therefore the sense of smell does not provide
adequate protection against its toxic effects.
Contact with the skin can cause major damage, including severe blistering. Symptoms
may take several hours to appear. The response is amplified if the skin is wet or
sweaty. Ethylene oxide is also a skin sensitizer and may trigger an allergic skin
reaction. Contact with eyes is severely irritation and may cause irreversible damage.
Contact with liquid ethylene oxide can cause severe frostbite.
EXPOSURE LIMITS
Cal-OSHA has established maximum inhalation exposure limits for workers in
occupational settings for over 500 chemicals. These are known as Permissible
Exposure Limits and cannot legally be exceeded. For ethylene oxide the PELs are
quite low:
Template rev. 11/14
1 ppm - 8 hour time weighted average exposure
5 ppm - 15 min. time-weighted average exposure (short term exposure limit)
Therefore, work with ethylene oxide should always be done in a fume hood, glove box,
or in totally-sealed containers to keep exposures as low as possible. Contact EH&S if
you believe you are being exposed. In some instances EH&S can do quantitative
exposure monitoring.
PERSONAL PROTECTIVE EQUIPMENT (PPE)
See the PPE information under Sec. II of the UCSB Chemical Hygiene Plan regarding:
 the UC PPE Policy and policy summary (what PPE is needed and when/where to
use)
 obtaining your PPE via use of the Laboratory Hazard Assessment Tool
 glove selection criteria
 respirator use, etc.
NIOSH recommends butyl rubber, Teflon or Silvershield gloves.
OSHA recommends against contact lens use when working with acrylonitrile, methylene
chloride, 1,2-dibromo-3-chloropropane methylene dianiline and ethylene oxide.
Safety glasses may be adequate when handling very small quantities of ethylene oxide.
However, the use of tight-fitting splash goggles is highly recommended, as well as a
face shield in higher splash risk situations.
ENGINEERING/VENTILATION CONTROLS
For further information see the following pages in Sec. II of the Chemical Hygiene Plan:
 Fume Hood Usage Guide
 Criteria for Implementing Engineering Controls
SPECIAL HANDLING PROCEDURES AND STORAGE REQUIREMENTS
Handling
 Avoid contact with skin and eyes. Avoid inhalation.
 Use explosion-proof equipment and prevent buildup of electrostatic charge via
appropriate grounding and bonding.
 Keep away from sources of ignition
Storage
 Protect containers from physical damage.
 Keep container tightly closed in a dry and well-ventilated place.
 Recommended storage temperature 2-8 oC. Never store above 52 oC.
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SPILL AND INCIDENT PROCEDURES
See directions under the “Chemical Incident” tab of the UCSB Emergency Information
Flipchart – should already be posted in all labs.
In case of skin contact
Immediately (within seconds) flush affected area for at least 15 minutes. Remove all
contaminated clothing. Call 9-911 from a campus phone to get immediate emergency
medical attention.
In case of eye contact
Use Emergency Eyewash immediately. Call 9-911 from a campus phone to get
immediate emergency medical attention. Continue flushing eyes until emergency
responders arrive.
DECONTAMINATION
Using proper personal protective equipment as outlined above, decontaminate
equipment and bench tops using soap and water and properly dispose of all chemical
and contaminated disposables as hazardous waste following the guidelines below.
WASTE DISPOSAL
See “Chemical Waste Disposal” in Sec. II of the UCSB Chemical Hygiene Plan.
PRIOR APPROVAL/REVIEW REQUIRED
As they deem necessary, the PI/supervisor should insert here any prior approval or
review needed before an individual can do the operation.
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DESIGNATED AREA
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whether a special use-area is designated for this material/process.
SAFETY DATA SHEETS
Found online at: http://ehs.ucsb.edu/labsafety/msds
LAB-SPECIFIC INFORMATION (required) (Examples of appropriate content)
Add appropriate lab-specific information here describing how this material(s) is
generally used. E.g., name of protocol, typical frequency done, quantities used,
temperature and any additional safety measures, etc.
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