| Agent Name | Ethylene oxide |
|---|---|
| CAS Number | 75-21-8 |
| Formula | C2-H4-O |
| Major Category | Pesticides |
| Synonyms | Dimethylene oxide; 1,2-Epoxy ethane; Oxirane; [NIOSH] |
| Category | Fumigants |
| Description | Colorless gas or liquid (below 51 degrees F) with an ether-like odor; [NIOSH] Vapor density = 1.49 (heavier than air); [HSDB] |
| Sources/Uses | Ethylene oxide sterilizers are used by medical and dental staff to sterilize heat-sensitive instruments. [p. 736, Harber] Occupational asthma from ethylene oxide has been reported in a nurse. [Malo] |
| Comments | Acute inhalation injuries result from exposures between 200 and 400 ppm. At higher concentrations, ethylene oxide (EtO) may cause neurological dysfunction. Chronic effects of exposure include reproductive toxicity and peripheral neuropathy. [LaDou, p. 456-8] The most common skin effects are irritation and second degree burns, but allergic contact dermatitis has been reported. [Sullivan, p. 1135] Healthcare workers performing EtO sterilization may develop cataracts. Highest exposures occurred during unloading (especially when the sterilization cycle was interrupted) and during cylinder changing. [J Occup Environ Med 1999 Jun;41(6):492-9] Listed as one of "major irritant airborne toxicants"; [LaDou, p. 547] There is limited positive data that EtO causes spontaneous abortions in humans and birth defects and testicular damage in experimental animals. [ATSDR Case Studies #29] [Ethylene oxide allergy in dialysis patients. Purello D'Ambrosio F, et al. Nephrol Dial Transplant. 1997 Jul;12(7):1461-3.] [Airborne occupational contact dermatitis from ethylene oxide. Romaguera C, et al. Contact Dermatitis. 1998 Aug;39(2):85.] Liquid causes second degree burns after contact for a few minutes. [CHRIS] Corrosive to skin; [Quick CPC] "Germ cell mutagens that have shown to increase the mutant frequency in the progeny of exposed mammals." [MAK] "Although the IARC Working Group concluded that the epidemiological evidence for carcinogenicity of EO was limited, EO was classified as a category 1 carcinogen because of its rodent carcinogenicity, alkylating properties and ability to cause chromosomal aberrations. However, the substantial epidemiological evidence regarding carcinogenic effects of EO to date does not show any consistent carcinogenic effects in humans and clearly these alkylating properties have not led to any consistent cancer excess in exposed populations." [PMID 19430313] |
| Reference Link | |
| Exposure Assessment | |
| Skin Designation (ACGIH) | Yes |
| TIH | Yes |
| PEL (OSHA) | 1 mg/m3, STEL(OSHA) = 5 ppm |
| Excerpts from Documentation for IDLHs | Reports of effects in humans include: nasal irritation after exposures to 12,500 ppm for 10 sec. Acute studies in animals have shown: death after exposure > 8000 ppm for 10 min.; no apparent injuries after exposure to 4000 ppm for 30 min., 2000 ppm for 60 min., or 500 ppm for 1 hr. |
| Odor Threshold Low | 257 ppm |
| Odor Threshold High | 690 ppm |
| Lethal Concentration | LC50 (rat) = 800 ppm/4H |
| Explanatory Notes | Detection odor threshold from AIHA (mean = 420 ppm); |
| Half Life | No reports found; [TDR, p. 694] |
| Reference Link | |
| Flammability (NFPA) | |
| Adverse Effects | |
| Reproductive Toxin | Yes |
| Skin Sensitizer | Yes |
| Asthma | Yes |
| Toxic Pneumonitis | Yes |
| Neurotoxin | Sensorimotor Neuropathy |
| Hepatotoxin | Hepatotoxin, Secondary |
| Dermatotoxin | Skin Burns |
| IARC Carcinogen | Known Carcinogen |
| Links to Other NLM Databases | |
| Health Studies | Human Health Effects from Hazardous Substances Data Bank: |
| Toxicity Information | |
| Chemical Information | |
| Biomedical References | |
| Related Information in HazMap | |
| Diseases | Occupational diseases associated with exposure to this agent: |
| Processes | Industrial Processes with risk of exposure: |