Add to MyChemicals Print Friendly Page
Chemical Datasheet

ETHYLENE OXIDE

2.3 - Poisonous gas 2.1 - Flammable gas
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

The Chemical Identifier fields include common identification numbers, the NFPA diamond U.S. Department of Transportation hazard labels, and a general description of the chemical. The information in CAMEO Chemicals comes from a variety of data sources.
CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 75-21-8   (ETHYLENE OXIDE)
  • Poison Gas
  • Flammable Gas
NIOSH Pocket Guide International Chem Safety Card
Ethylene oxideexternal link
NFPA 704
Diamond Hazard Value Description
4
3 3
Blue Health 3 Can cause serious or permanent injury.
Red Flammability 4 Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature.
Yellow Instability 3 Capable of detonation or explosive decomposition or explosive reaction but requires a strong initiating source or must be heated under confinement before initiation.
White Special
(NFPA, 2010)
General Description
A clear colorless gas with an ethereal odor with a flash point below 0°F. Liquid less dense than water. Vapors heavier than air.

May polymerize exothermically if heated or contaminated. If the polymerization takes place inside a container, the container may rupture violently.

Vapors very toxic. Vapors irritate the eyes, skin, and respiratory system. Prolonged skin contact may result in delayed burns.

Used to make other chemicals, as a fumigant and industrial sterilant.

Hazards

The Hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially incompatible absorbents. The information in CAMEO Chemicals comes from a variety of data sources.
Reactivity Alerts
Air & Water Reactions
Highly flammable. Flammable over a wide vapor-air concentration range. Must be diluted on the order of 24 to 1 with water to lose flammability. Soluble in water.
Fire Hazard
Severe explosion hazard when exposed to heat or flame. Irritating vapors are generated when heated. Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back. Vapor forms explosive mixtures with air over a wide range. Liquid is not detonable but the vapor may be readily initiated into explosive decomposition. Avoid metal fittings containing copper, silver, mercury or magnesium; ammonia, oxidizing agents; acids, organic bases; amines; certain salts; alcohols; mercaptans, ferric chloride; magnesium perchlorate; m-nitroaniline; trimethylamine, potassium, tin chlorides; alkanethiols; bromoethane; aluminum chloride; aluminum oxide; iron chlorides; and iron oxides. Avoid air, heat, acids and bases, metal or metal chloride catalysts. Hazardous polymerization may occur. Avoid acids; covalent halides such as chlorides of aluminum, iron (III), tin (IV); basic materials like alkali hydrides, ammonia, amines, and potassium; catalytically active solids such as aluminum or iron oxides or rust, chlorides of boron, aluminum, tin, and iron; some carbonates; and metals such as copper and copper alloys (EPA, 1998)
Health Hazard
It can cause death. Lowest inhalation concentration causing toxic effects is 12500 ppm/10 seconds. It is a strong skin irritant. Neurological disorders and even death have been reported. (EPA, 1998)
Reactivity Profile
Colorless gas at room temperature (b.p. 11°C), confirmed carcinogen. Highly flammable, severe explosion hazard when exposed to flame. The autoignition temperature may be as low as 140°C in presence of rust. Rapid compression of the vapor with air causes explosion. Ethylene oxide vapor may be initiated into explosive decomposition in absence of air [Hess, L. G., et al., Ind. Eng. Chem., 1950, 42, p. 1251]. Metal fittings containing magnesium, copper or silver should be avoided, since traces of acetylene in ethylene oxide may produce metal acetylides capable of detonating the vapor [MCA SD-38, 1971]. Violent polymerization occurs on contact with strong bases (alkali hydroxides, ammonia) or acids, amines, metallic potassium, oxides (aluminum oxide, iron oxide, rust), covalent halides (aluminum chloride, ferric chloride, tin(IV) chloride) [Gupta, A. K., J. Soc. Chem. Ind., 1949, 68, p. 179]. Violent reaction with m-nitroaniline, magnesium perchlorate, mercaptans, thiols, triethylamine [Bretherick, 5th ed., 1995, p. 316]. Ethylene oxide and SO2 can react violently in pyridine solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below. More info about absorbents, including situations to watch out for...

Response Recommendations

The Response Recommendation fields include isolation and evacuation distances, as well as recommendations for firefighting, non-fire response, protective clothing, and first aid. The information in CAMEO Chemicals comes from a variety of data sources.
Isolation and Evacuation
Excerpt from ERG Guide 119(P) [Gases - Toxic - Flammable; polymerization hazard]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

SPILL: See ERG Tables 1 and 3 - Initial Isolation and Protective Action Distances on the UN/NA 1040 datasheet.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. (ERG, 2020)
Firefighting
Move container from fire area if you can do so without risk. Stay away from ends of tanks. Fight fire from maximum distance. For massive fire in cargo area, use unmanned hose holder or monitor nozzles; if this is impossible, withdraw from area and let fire burn. Withdraw immediately in case of rising sound from venting safety device or any discoloration of tank due to fire. Isolate for 1 mile in all directions if tank car or truck is involved in fire. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Wear positive pressure breathing apparatus and full protective clothing. Evacuate area endangered by gas.

Extinguish with alcohol foam, carbon dioxide, dry chemical or water spray, fog, or foam. Let burn unless leak can be stopped immediately. (EPA, 1998)
Non-Fire Response
Excerpt from ERG Guide 119(P) [Gases - Toxic - Flammable; polymerization hazard]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Do not direct water at spill or source of leak. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. FOR CHLOROSILANES, use AFFF alcohol-resistant medium-expansion foam to reduce vapors. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Isolate area until gas has dispersed. (ERG, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Ethylene oxideexternal link:

Skin: PREVENT SKIN CONTACT (LIQUID) - If this chemical is in liquid form, wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT (LIQUID) - If this chemical is in liquid form, wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED (LIQUID) - If this chemical is in liquid form, the worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide: QUICK DRENCH (LIQUID) - Facilities for quickly drenching the body should be provided (when this chemical is in liquid form) within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2022)
DuPont Tychem® Suit Fabrics
Tychem® Fabric Legend
QS = Tychem 2000 SFR
QC = Tychem 2000
SL = Tychem 4000
C3 = Tychem 5000
TF = Tychem 6000
TP = Tychem 6000 FR
RC = Tychem RESPONDER® CSM
TK = Tychem 10000
RF = Tychem 10000 FR
Testing Details
The fabric permeation data was generated for DuPont by a third party laboratory. Permeation data for industrial chemicals is obtained per ASTM F739. Normalized breakthrough times (the time at which the permeation rate exceeds 0.1 μg/cm2/min) are reported in minutes. All chemicals have been tested between approximately 20°C and 27°C unless otherwise stated. All chemicals have been tested at a concentration of greater than 95% unless otherwise stated. Chemical warfare agents (Lewisite, Sarin, Soman, Sulfur Mustard, Tabun and VX Nerve Agent) have been tested at 22°C and 50% relative humidity per military standard MIL-STD-282. "Breakthrough time" for chemical warfare agents is defined as the time when the cumulative mass which permeated through the fabric exceeds the limit in MIL-STD-282 [either 1.25 or 4.0 μg/cm2].
A Caution from DuPont
This information is based upon technical data that DuPont believes to be reliable on the date issued. It is subject to revision as additional knowledge and experience are gained. The information reflects laboratory performance of fabrics, not complete garments, under controlled conditions. It is intended for informational use by persons having technical skill for evaluation under their specific end-use conditions, at their own discretion and risk. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. Anyone intending to use this information should first verify that the garment selected is suitable for the intended use. In many cases, seams and closures have shorter breakthrough times and higher permeation rates than the fabric. If fabric becomes torn,abraded or punctured, or if seams or closures fail, or if attached gloves, visors, etc. are damaged, end user should discontinue use of garment to avoid potential exposure to chemical. Since conditions of use are outside our control, DuPont makes no warranties, express or implied, including, without limitation, no warranties of merchantability or fitness for a particular use and assume no liability in connection with any use of this information. This information is not intended as a license to operate under or a recommendation to infringe any patent, trademark or technical information of DuPont or others covering any material or its use.
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Epoxy ethane (-70°C, liquid) 75-21-8 Liquid >180
Epoxy ethane (0°C, liquid) 75-21-8 Liquid >480 >480 >480
Epoxy ethane (10% in HCFC) 75-21-8 Vapor >480
Epoxy ethane (11°C, liquid) 75-21-8 Liquid 18
Epoxy ethane (gaseous) 75-21-8 Vapor imm imm >480 126 >480 >480 >480 >480
Ethylene oxide (-70°C, liquid) 75-21-8 Liquid >180
Ethylene oxide (0°C, liquid) 75-21-8 Liquid >480 >480 >480
Ethylene oxide (10% in HCFC) 75-21-8 Vapor >480
Ethylene oxide (11°C, liquid) 75-21-8 Liquid 18
Ethylene oxide (gaseous) 75-21-8 Vapor imm imm >480 126 >480 >480 >480 >480
> indicates greater than.
"imm" indicates immediate; having a normalized breakthrough time of 10 minutes or less.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

...Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments are designed and tested to help reduce burn injury during escape from a flash fire. Users of Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments should not knowingly enter an explosive environment. Tychem® garments with attached socks must be worn inside protective outer footwear and are not suitable as outer footwear. These attached socks do not have adequate durability or slip resistance to be worn as the outer foot covering.

(DuPont, 2022)

First Aid
Warning: Ethylene oxide is corrosive to moist tissues. Caution is advised.

Signs and Symptoms of Acute Ethylene Oxide Exposure: Signs and symptoms of acute exposure to ethylene oxide may be severe, and include dyspnea (shortness of breath), cough, pulmonary edema, pneumonia, and respiratory failure. Lethargy, headache, dizziness, twitching, convulsions, paralysis, and coma may be observed. Cardiac arrhythmias and cardiovascular collapse may also occur. Gastrointestinal effects of acute exposure may include nausea, vomiting, and abdominal pain. Ethylene oxide may severely irritate or burn mucous membranes and moist skin. Eye contact may result in conjunctivitis (red, inflamed eyes) and erosion of the cornea.

Emergency Life-Support Procedures: Acute exposure to ethylene oxide may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to ethylene oxide.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Transport to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self- exposure to ethylene oxide.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Remove contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be IMMEDIATELY flushed with lukewarm water for AT LEAST 15 minutes.
5. If liquid is spilled on the skin, allow ethylene oxide to vaporize before washing THOROUGHLY with soap and water.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Transport to a health care facility.

Ingestion Exposure:
1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
3. Give the victims water or milk: children up 1 year old, 125 mL (4 oz or 1/2 cup); children 1 to 12 years old 200 mL (6 oz or 3/4 cup); adults, 250 mL (8 oz or 1 cup). Water or milk should be given only if victims are conscious and alert.
4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.
5. Ethylene oxide generally acts as its own cathartic; however, if deemed necessary, excretion may be promoted by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.
6. Transport to a health care facility. (EPA, 1998)

Physical Properties

The Physical Property fields include properties such as vapor pressure and boiling point, as well as explosive limits and toxic exposure thresholds The information in CAMEO Chemicals comes from a variety of data sources.
Chemical Formula:
  • C2H4O
Flash Point: -0.4 to 0°F (EPA, 1998)
Lower Explosive Limit (LEL): 3 % (EPA, 1998)
Upper Explosive Limit (UEL): 100 % (EPA, 1998)
Autoignition Temperature: 804°F (USCG, 1999)
Melting Point: -170.5°F (EPA, 1998)
Vapor Pressure: 1095 mmHg at 68°F (EPA, 1998)
Vapor Density (Relative to Air): 1.49 (EPA, 1998)
Specific Gravity: 0.8222 at 50°F (EPA, 1998)
Boiling Point: 51.3°F at 760 mmHg (EPA, 1998)
Molecular Weight: 44.06 (EPA, 1998)
Water Solubility: Miscible (NTP, 1992)
Ionization Energy/Potential: 10.56 eV (NIOSH, 2022)
IDLH: 800 ppm ; A potential occupational carcinogen. (NIOSH, 2022)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Ethylene oxide (75-21-8)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes NR 80 ppm 360 ppm
30 minutes NR 80 ppm 360 ppm
60 minutes NR 45 ppm 200 ppm
4 hours NR 14 ppm 63 ppm
8 hours NR 7.9 ppm 35 ppm
NR = Not recommended
(NAC/NRC, 2022)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Ethylene Oxide (75-21-8) NA 50 ppm 500 ppm
NA = not appropriate.
(AIHA, 2020)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Ethylene oxide; (Oxirane) (75-21-8) 5 ppm 45 ppm 200 ppm LEL = 30000 ppm
(DOE, 2018)

Regulatory Information

The Regulatory Information fields include information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists, the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards, and the U.S. Occupational Safety and Health Administration's Process Safety Management of Highly Hazardous Chemicals Standard List (see more about these data sources).

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Ethylene oxide 75-21-8 1000 pounds 10 pounds 10 pounds 313 U115 10000 pounds
Oxirane 75-21-8 1000 pounds 10 pounds 10 pounds X U115 10000 pounds

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

RELEASE THEFT SABOTAGE
Chemical of Interest CAS Number Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Ethylene oxide; [Oxirane] 75-21-8 1.00 % 10000 pounds flammable

(CISA, 2007)

OSHA Process Safety Management (PSM) Standard List

Chemical Name CAS Number Threshold Quantity (TQ)
Ethylene Oxide 75-21-8 5000 pounds

(OSHA, 2019)

Alternate Chemical Names

This section provides a listing of alternate names for this chemical, including trade names and synonyms.