Inhalation of ethylene oxide

Toxicology. An excellent review of the toxicity and health assessment of ethylene oxide has been compiled (233). Ethylene oxide (EO) can be relatively toxic as both a Hquid and gas. Inhalation of ethylene oxide ia high concentrations may be fatal. Estimates of lethal ethylene oxide inhalation levels in animals depend on the duration of exposure. The reported 4-h LC q values for rats, mice, and dogs are 1460, 835, and 960 ppm, respectively (234). More recent information (235) indicates that the 1-h LC q in rats is approximately 5000 ppm. 

Toxicity of EtnO (Ref 17, pp 314—15 Spec MIL-E-52171). Liquid EtnO, concentrated or dilute, when exposed to the skin can cause -severe delayed bums. Short exposures produce mild first degree bums, but prolonged exposures produce second degree bums with the formation of large blisters. Exposure to the vapor results in systemic manifestations and irritation to the respiratory system. Inhalation of ethylene oxide vapors, if. prolonged, results in severe systemic poisoning with the symptoms of nausea, vomiting, headache, dysnea, and diarthea. The anesthetic properties are similar to chloroform, but with pronounced undesirable side and after effects. 

If contact with the liquid or its solutions occurs, affected areas should be flushed thoroughly with water for at least 15 min. The areas should be observed for burns or resulting irritation. In case of inhalation of ethylene oxide, the victim should be moved to fresh air, an airway should be established, and respiration should be maintained as necessary. The victim should be monitored for irritation, bronchitis, and pneumonitis. If excessive exposure occurs, hospitalization and monitoring for delayed pulmonary edema is recommended. 

Leong. B.K.J. Ts o. T.O.T. Testicular atrophy from inhalation of ethylene oxide cyclic tetramer. Toxicol. Appl. Pharmacol. 1974. 27. 342-354. 

Inhalation exposure to high concentrations of ethylene oxide has been reported to result in respiratory system irritation and edema (236). 

In an animal study of rats exposed by inhalation to ethylene oxide at 10, 33, or 100 ppm for approximately two years (245), and in a separate chronic rat study in which rats were exposed to 50 or 100 ppm of ethylene oxide (240), increased incidences of mononuclear cell leukemia, peritoneal mesothelioma, and various brain tumors have been reported. In an NTP (246) two-year inhalation study of mice at 50 and 100 ppm, alveolar/bronchiolar carcinomas and adenomas, papillary cystadenomas of the harderian gland, and malignant lymphomas, uterine adenocarcinomas, and mammary gland tumors were increased in one or both exposure groups. 

Several industrial facilities near a residential area emit tlie inhalable pollutants ethylene oxide, polychlorobiphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Tlie aimual average concentration of ethylene oxide, PCBs, and PAHs are 10 pg/in, 2 pg/m, and 5 pg/m, respectively. 

Snellings W, Weil C, Maronpot R A two-year inhalation study of the carcinogenic potential of ethylene oxide in Fischer 344 rats. Toxicol Appl Pharmacol 75 105-117, 1984... 

Filser, J.C. Bolt, H.M. (1984) Inhalation pharmacokinetics based on gas uptake studies VI. Comparative evaluation of ethylene oxide and butadiene monoxide as exhaled reactive metabolites of ethylene and 1,3-butadiene in rats. Arch. Toxicol., 55, 219-223... 

The reagent has b.p. 11 °C and is supplied either in 100-ml sealed tubes or in 100-ml cylinders equipped with an appropriate valve. The gas, which is highly flammable, has no very distinctive smell and must be regarded as a hazardous toxic reagent which must not be inhaled or allowed to come into contact with the skin and eyes. Precautions in the use of ethylene oxide are described in Expt 5.39, which may be regarded as typical. 

Absorbed ethylene oxide is rapidly distributed throughout the body. In mice exposed by inhalation to radiolabeled ethylene oxide, distribution was immediate, with the highest concentrations of ethylene oxide or its metabolites in the lungs, liver, and kidneys. After 4 h, levels in the liver and kidney had decreased and were comparable to those detected in the lungs, testes, spleen, and brain. 

Inhalation. Workers who develop symptoms or signs of ethylene oxide toxicity should be removed immediately from the contaminated area. Oxygen can be administered to workers with persistent dyspnea. 

Polymers. Studies to determine possible exposure of workers to residual epichl orohydrin and ethylene oxide monomers in the polymers have been done. Tests of warehouse air where Hydrin H and Hydrin C are stored showed epichl orohydrin levels below 0.5 ppm. Air samples taken above laboratory mixing equipment (Banbury mixer and 6" x 12" mill) when compounds of Hydrin H or C were mixed gave epichl orohydrin levels below detectable limits, and ethylene oxide levels less than 0.2 ppm, well below permissible exposure limits (46). A subacute vapor inhalation toxicity study in which animals were exposed to emission products from compounded Parel 58 suggests that no significant health effects would be expected in workers periodically exposed to these vapors (47). 

Ethylene oxide has been shown to produce mutagenic and cytogenic effects in a variety of test systems (226). An increased frequency of chromosomal aberrations in peripheral lymphocytes of monkey exposed to ethylene oxide for 104 weeks has been reported (240). In mice, it is an effective inducer of chromosome breaks leading to dominant-lethal mutations. In addition, ethylene oxide has been shown to induce heritable effects in the heritable translocation test conducted in mice exposed to ethylene oxide by inhalation (241,242). In this study, male mice were exposed to ethylene oxide ranging from 165 to 300 ppm for 6 h per day 5 or 7 days/week for 8.5 weeks. Ethylene oxide has also been shown to bind to proteins (243) as well as to DNA (244). Several studies on ethylene oxide-exposed workers have demonstrated an increased incidence of chromosomal aberrations and sister chromatid exchanges the relevance of such effects to human health evaluation is currendy uncertain. 

In a chronic inhalation bioassay in rats exposed for 6 hours/day, 5 days/week for 2 years to 100, 33, or 10ppm ethylene oxide, there was a dose-related increased occurrence of mononuclear cell leukemia in both sexes at all concentrations. There was also an increased occurrence of primary brain tumors at 100 and 33 ppm in both sexes and peritoneal mesotheliomas arising from the testicular serosa at 100 and 33 ppm in male rats. ... 

Jacobson KH, Hackley EB, Eeinsilver L The toxicity of inhaled ethylene oxide and propylene oxide vapors. AMA Arch Ind Health 13 237-244, 1956... 

Lynch, D. W., Lewis, T. T, et al. 1984. Carcinogenic and toxicologic effects of inhaled ethylene oxide and propylene oxide in F 344 rats. Toxicology and Applied Pharmacology 76 69-84. 

Ethylene oxide, (CH2)20 (bp 10.7°C)—Ethylene oxide is mainly used as a mixture with carbon dioxide for vault fumigation of stored food products. Its inhalation LC50 (4 hr) in rats is 1462 ppm. 

SAFETY PROFILE A poison. Mildly toxic by inhalation. Used for the sterilization of vacuum chambers. See also ETHYLENE OXIDE. 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by intraperitoneal route. Moderately toxic by inhalation. A corrosive irritant to skin, eyes, and mucous membranes. Combustible by chemical reaction. Upon contact with moisture, considerable heat is generated. Violent reaction with K, Na, turpentine, ethylene oxide, alkyl nitrates. Dangerous hydrochloric acid is liberated on contact with moisture or heat. When heated to decomposition it emits toxic fumes of CL. See also HYDROCHLORIC ACID. 

SAFETY PROFILE Poison by intravenous route. Moderately toxic by subcutaneous and rectal routes. Mildly toxic by inhalation. A ver). dangerous fire hazard when exposed to heat or flame. Self-reactive. Moderately explosive in the form of vapor when exposed to heat or flame. Can react with oxidizing materials. To fight fire, stop flow of gas. Potentially explosive reaction with bromine + heat, ethylene oxide, triethynylaluminum. When heated to decomposition it emits toxic fumes of NOx. See also AMINES. 

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