Ethylene oxide

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. 501] 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] 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] "There were reports from Sweden among producers and some users of ethylene oxide that hinted at excess risks of leukemia. But larger American studies have subsequently shown no such risk." [Boffetta, p. 3] Ethylene oxide (UN1040) has warning of explosive polymerization; [ERG 2016]

Reference Link #1

Biomedical References

N-(2-hydroxyethyl)valine (HEV) hemoglobin adducts = 5000 pmol HEV/g globin. See urine BEI and further details. [TLVs and BEIs]

Yes

Yes

1 ppm

1 ppm, STEL(OSHA) = 5 ppm

800 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.

257 ppm

Odor Threshold High

690 ppm

LC50 (rat) = 800 ppm/4H

Yes

Explanatory Notes

Detection odor threshold from AIHA (mean = 420 ppm);

No reports found; [TDR, p. 694]

Reference Link #2

burn readily

Not appropriate

50 ppm

500 ppm

Yes

Yes

Yes

Sensorimotor

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Skin burns

Established

Human carcinogen

Suspected Human

Diseases

Occupational diseases associated with exposure to this agent:

• Asthma, occupational
• Cataract, chemical or radiation induced
• Contact dermatitis, allergic
• Fumigants, acute toxic effect
• Neuropathy, toxic
• Pneumonitis, toxic
• Spontaneous abortions

Processes

Industrial Processes with risk of exposure:

• Sterilizing Equipment