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Chemical Datasheet

ETHYLENE OXIDE WITH NITROGEN

2.3 - Poisonous gas 2.1 - Flammable gas

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 75-21-8   (ETHYLENE OXIDE)
  • 7727-37-9
  • 1040
  • Poison Gas
  • Flammable Gas
none
NIOSH Pocket Guide International Chem Safety Card
Ethylene oxide
  • ETHYLENE OXIDE
  • NITROGEN (COMPRESSED GAS)
  • NITROGEN (LIQUIFIED)
NFPA 704
Diamond Hazard Value Description
4
3 2
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 2 Readily undergoes violent chemical changes at elevated temperatures and pressures.
White Special
Note: NFPA ratings shown are for ethylene oxide, CAS number 75-21-8.
(NFPA, 2010)
General Description
A nonflammable colorless gas. Vapors heavier than air. May asphyxiate by the displacement of air, especially in confined places.

Hazards

Reactivity Alerts
Air & Water Reactions
No rapid reaction with air. No rapid reaction with water.
Fire Hazard
Excerpt from 119 Polymerizable warning [Gases - Toxic - Flammable; polymerization hazard]:

Flammable; may be ignited by heat, sparks or flames. May form explosive mixtures with air. Ethylene oxide (UN1040) may react explosively even in the absence of air. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. Runoff may create fire or explosion hazard. (ERG, 2020)
Health Hazard
Excerpt from 119 Polymerizable warning [Gases - Toxic - Flammable; polymerization hazard]:

TOXIC; may be fatal if inhaled or absorbed through skin. Some may cause severe skin burns and eye damage. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2020)
Reactivity Profile
ETHYLENE OXIDE is a colorless gas at room temperature (b.p. 11°C) and a confirmed carcinogen. By itself, is 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].
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.

Response Recommendations

Isolation and Evacuation
Excerpt from 119 Polymerizable warning [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
Excerpt from 119 Polymerizable warning [Gases - Toxic - Flammable; polymerization hazard]:

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant foam. FOR CHLOROSILANES, DO NOT USE WATER; use AFFF alcohol-resistant medium-expansion foam. If it can be done safely, move undamaged containers away from the area around the fire. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2020)
Non-Fire Response
Excerpt from 119 Polymerizable warning [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 ERG Guide 119(P) [Gases - Toxic - Flammable; polymerization hazard]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2020)
DuPont Tychem® Suit Fabrics
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...

(DuPont, 2023)

First Aid
Excerpt from 119 Polymerizable warning [Gases - Toxic - Flammable; polymerization hazard]:

Call 911 or emergency medical service. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air if it can be done safely. Give artificial respiration if victim is not breathing. Do not perform mouth-to-mouth resuscitation if victim ingested or inhaled the substance; wash face and mouth before giving artificial respiration. Use a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. Keep victim calm and warm. Keep victim under observation. Effects of contact or inhalation may be delayed. (ERG, 2020)

Physical Properties

Chemical Formula:
  • C2H4O
  • N2
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: data unavailable
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity: data unavailable
Boiling Point: data unavailable
Molecular Weight: data unavailable
Water Solubility: data unavailable
Ionization Energy/Potential: 10.56 eV [From NPG: Ethylene oxide] (NIOSH, 2023)
IDLH: 800 ppm ; A potential occupational carcinogen. [From NPG: Ethylene oxide] (NIOSH, 2023)

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, 2023)

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, 2022)

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
Nitrogen (7727-37-9) 796000 ppm 832000 ppm 869000 ppm
(DOE, 2018)

Regulatory Information

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