# NIOSH Pocket Guide to Chemical Hazards
Ethylene oxide | CAS 75-21-8
C2H4O | RTECS KX2450000
Synonyms & Trade Names Dimethylene oxide; 1,2-Epoxy ethane; Oxirane | DOT ID & Guide 1040 119
Exposure Limits | NIOSH REL: Ca TWA <0.1 ppm (0.18 mg/m3) C 5 ppm (9 mg/m3) [10-min/day] See Appendix A
OSHA PEL: [1910.1047] TWA 1 ppm 5 ppm [15-minute Excursion]
IDLH Ca [800 ppm] | Conversion 1 ppm = 1.80 mg/m3
Physical Description Colorless gas or liquid (below 51°F) with an ether-like odor.
MW: 44.1 | BP: 51°F | FRZ: -171°F | Sol: Miscible
VP: 1.46 atm | IP: 10.56 eV | RGasD: 1.49 | Sp.Gr: 0.82 (Liquid at 50°F)
Fl.P: NA (Gas) -20°F (Liquid) | UEL: 100% | LEL: 3.0% |
Flammable Gas Class IA Flammable Liquid
Incompatibilities & Reactivities Strong acids, alkalis & oxidizers; chlorides of iron, aluminum & tin; oxides of iron & aluminum; water
Measurement Methods NIOSH 1614, 3800; OSHA 30, 49, 50
Personal Protection & Sanitation Skin: Prevent skin contact (liquid) Eyes: Prevent eye contact (liquid) Wash skin: When contaminated (liquid) Remove: When wet (flammable) Change: No recommendation Provide: Quick drench (liquid) | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush immediately Breathing: Respiratory support Swallow: Medical attention immediately (liquid)
Respirator Recommendations NIOSH Up to 5 ppm: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern†/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern†/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion (liquid), skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; peculiar taste; headache; nausea, vomiting, diarrhea; dyspnea (breathing difficulty), cyanosis, pulmonary edema; drowsiness, lassitude (weakness, exhaustion), incoordination; EKG abnormalities; eye, skin burns (liquid or high vapor concentration); liquid: frostbite; reproductive effects; [potential occupational carcinogen]; in animals: convulsions; liver, kidney damage
Target Organs Eyes, skin, respiratory system, liver, central nervous system, blood, kidneys, reproductive system Cancer Site [peritoneal cancer, leukemia]
See also: INTRODUCTION