What Is Ethylene Oxide Toxicity?
Ethylene oxide is primarily used as a chemical intermediary in the production of ethylene glycol. Additionally, ethylene oxide is used to fumigate spices and sterilize medical equipment. People exposed to ethylene oxide experience its acute (short-term) effects, mostly as mucous membrane and ocular discomfort as well as central nervous system depression, and those who are exposed to ethylene oxide over an extended period may have eye, skin, nose, throat, and lung irritation as well as brain and nervous system damage. In addition, there is some evidence that ethylene oxide exposure negatively affects reproduction. According to the EPA (environmental protection agency), ethylene oxide can cause cancer when people breathe it in. There is evidence in people that ethylene oxide exposure raises the risk of lymphoid cancer and, in women, breast cancer.
What Are the Uses of Ethylene Oxide?
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In the production of ethylene glycol (antifreeze), textiles, detergents, polyurethane foam, solvents, medications, adhesives, and other goods, ethylene oxide is mostly employed as a chemical intermediary.
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Ethylene oxide is used in tiny quantities as a fumigant, a sterilant for food (spices) and cosmetics, and in hospitals to sterilize plastic gadgets and surgical instruments that cannot be sterilized by steam.
What Are the Potential Sources of Ethylene Oxide?
Uncontrolled emissions or leaking of other gasses in industrial settings are two sources of ethylene oxide emissions into the air. Medical equipment sterilization and the release of ethylene oxide from items fumigated for common use are two additional sources of ethylene oxide air emissions.
Who Are Commonly Exposed to Ethylene Oxide?
The general public may be exposed to ethylene oxide by inhaling polluted air, smoking tobacco, or being close to someone smoking. For example, workers at ethylene oxide production or processing facilities, sterilization technicians, and fumigation personnel may be exposed at work.
What Are Health Hazards Caused Due to Ethylene Oxide?
1) Acute Effects:
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Acute effects include nausea, vomiting, neurological problems, bronchitis, pulmonary edema, and emphysema in employees exposed to high doses of ethylene oxide by acute inhalation. Human skin and eyes have irritated after dermal or ocular contact with ethylene oxide solutions. Animal tests, including acute exposure, have revealed that ethylene oxide has significant acute toxicity when inhaled.
2) Chronic Effects (Non-Cancer):
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The main side effects among employees exposed to ethylene oxide at low levels over several years include nervous system impacts and irritation of the eyes, skin, and respiratory passages (for example, headache, nausea, memory loss, numbness).
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Ethylene oxide does not have a reference dose (RfD) or reference concentration (RFC) set by the EPA. Based on the effects of ethylene oxide on mice's neurological systems, the California Environmental Protection Agency (CalEPA) determined a chronic inhalation reference exposure limit of 0.03 milligrams per cubic meter (mg/m3) (18 parts per billion [ppb]). A quantity at or below which it is unlikely that adverse health consequences would materialize is known as the CalEPA reference exposure level. It serves as a benchmark to evaluate the possible consequences rather than serving as a straight risk estimate. The likelihood of negative health impacts rises if lifetime doses surpass the reference exposure level.
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The ATSDR (agency for toxic substances and disease registry) has set a 0.2 mg/m3 (0.09 parts per million) intermediate inhalation minimum risk level (MRL). Based on an exposure below that linked to renal consequences in mice, the ATSDR set an intermediate inhalation minimum risk limit (MRL) of 0.2 mg/m3 (0.09 parts per million [ppm]). The MRL estimates the daily human exposure to a hazardous material that is anticipated to be free from considerable risk of harmful noncancer health consequences over a given exposure period. An intermediate MRL has an exposure window of two weeks to a year.
3) Effects on Reproduction and Development:
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Some data suggest that female employees exposed to ethylene oxide by inhalation may experience a higher risk of miscarriages.
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Various reproductive effects, such as a reduction in the number of implantation sites, a drop in the weight and concentration of the sperm in the testicles, and testicular degeneration, have been seen in animal trials where the subjects were exposed to inhalation levels of the substance.
4) Cancer Risk:
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Research on human workers has revealed an increased lymphoid and breast cancer incidence. Animals exposed to ethylene oxide by inhalation developed lymphoid cancer and cancers of the brain, lung, connective tissue, uterus, and mammary gland. The EPA has determined that exposure to ethylene oxide by breathing causes human cancer. The EPA also concludes that ethylene oxide toxicity has a mutagenic mechanism of action, given the strength of the data. Using mathematical models based on human and animal research, EPA calculates the likelihood that inhaling air having a particular quantity of a chemical may cause cancer. For both cancer types combined, the EPA estimated the inhalation unit cancer risk estimate for ethylene oxide to be 0.003 per g/m3 (lymphoid cancer and, in females, breast cancer).
What Are the Safety Precautions to Be Taken by Individuals to Prevent Toxicity?
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In the following situations, employers are required to develop a medical monitoring program for an employee with a qualified doctor.
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Always use goggles and skin protection when there is a possibility of splashes from liquid ethylene oxide.
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Put on the appropriate protective gear and other authorized personal protective equipment when using ethylene oxide.
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Throw away clothing exposed to ethylene oxide, and see a doctor.
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Avoid eating, drinking, and smoking while handling ethylene oxide.
Conclusion
The toxicity of ethylene oxide needs to be addressed properly. Awareness should be created among workers by creating programs for information, training and personal air monitoring for those exposed to ethylene oxide, above the action level, or over the excursion limit. Establish a medical surveillance program for workers who spend more than 30 days a year exposed to ethylene oxide levels above the action limit of 0.5 ppm. Care should be taken for all containers that might expose workers to levels of exposure at or above the action level, or the excursion limit should be marked with warning labels and prevent unnecessary exposure.
