Ethylene oxide is a colorless, flammable gas at room temperature and a liquid below 51 degrees Fahrenheit. It’s used to make chemicals for industrial, personal care products and consumer goods. Manufacturers also use it to sterilize some medical devices. Exposure can cause headaches, nausea, diarrhea, difficulty breathing and other problems. Long-term exposure can cause cancer in humans.
Ethylene oxide (EO) is an environmental pollutant and is toxic to humans. Congress classified it as a “hazardous air pollutant,” according to the United States Environmental Protection Agency.
Multiple studies have shown that EO increases the risk of several types of cancer. The EPA classified the chemical as a human carcinogen in 2016. Despite its toxicity, the chemical is still widely used.
The American Chemical Council has called it a versatile chemical that contributes to the American economy. For example, approximately 50 percent of sterile medical devices in the U.S. are sterilized with EO, according to the EPA’s FAQ page updated September 2022. That equates to about 20 billion devices each year. Food producers also use it to sterilize some food products, including spices, dried vegetables, certain dried herbs, walnuts and sesame seeds.
There are more than 90 processing plants across the country that work with EO and chemicals made from it. Thousands of Americans work directly or indirectly with the chemical.
The Occupational Safety and Health Administration (OSHA) requires employers to monitor employee exposure to EO and provide protective equipment to keep them safe. The EPA’s National Emission Standards for Hazardous Air Pollutants regulates EO atmosphere emissions.
Exposure to EO can cause a number of acute side effects and health problems. Most people aren’t at risk of toxic levels of exposure in the environment, but factory workers, agricultural workers and some hospital workers who work with the chemical may be at risk.
Ethylene Oxide Uses
Manufacturers use EO primarily in producing other chemicals used in consumer and industrial applications. The main chemical created from EO is ethylene glycol, a chemical used in products from brake fluid to industrial solvents. Some studies have found it in e-cigarette liquids.
EO is also used to create health care products and sterilize medical devices.
- Agricultural insecticide
- Chemicals used to create fabrics for clothes, pillows and carpets
- Fiberglass used in jet skis, bowling balls and other products
- Household cleaners
- Industrial cleaners
- Polyethylene terephthalate (PET) plastic resin used to make packaging and beverage containers
- Sterilizing medical devices that are too delicate or sensitive for high-heat sterilizing, such as knee implants, bandages, electronics and devices containing plastic
- Sterilizing spices
What Does Ethylene Oxide Kill?
Ethylene oxide can kill most viruses, bacteria, bacteria spores and fungi. It kills microorganisms by ripping apart cell membranes.
Because of this property, manufacturers often use EO to disinfect dry foods like spices and grains as well as medical devices and supplies like knee implants, catheters, syringes and surgical kits.
Side Effects of Ethylene Oxide Exposure
Most people don’t experience ethylene oxide side effects because they are not exposed to high amounts of the chemical every day.
People exposed to toxic amounts of EO typically inhale it, but it may also contaminate the skin or be ingested. Potential sources of exposure include uncontrolled emissions in industrial settings, contaminated air, tobacco smoke and the on-the-job exposure.
More severe side effects, such as fluid in the lungs that can lead to lung collapse, coma, cardiovascular collapse and respiratory paralysis, are more likely at larger doses and at longer durations of exposure.
The EPA hasn’t established a limit for safe EO exposure in the air.
- Difficulty breathing
- Eye burns
- Irritation of the eyes, nose, throat, skin and lungs
- Memory loss
- Reproductive effects
- Skin burns
Who Is Most at Risk?
People who work with ethylene oxide are most at risk of suffering health effects because of chronic exposure.
- Agricultural workers who use ethylene oxide as an insecticide for grain bins
- Factory workers in plants that make ethylene oxide
- Hospital workers or technicians who sterilize medical equipment and supplies with ethylene oxide
- Plant workers that use ethylene oxide to produce antifreeze, solvents, detergents, textiles, polyurethane foam and adhesives
What Cancers Can Ethylene Oxide Exposure Cause?
Because ethylene oxide destroys DNA, it can increase the risk of certain cancers. Studies show that long-term exposure to ethylene oxide can cause cancers of the white blood cells in humans, including non-Hodgkin lymphoma, myeloma and lymphocytic leukemia, according to the EPA. It also increases the risk of breast cancer in women.
Animal studies have shown it can cause brain, lung, connective tissue and uterine tumors.
The EPA hasn’t set limits for exposure, but the agency has said it “considers any exposure, however small, to a carcinogen to create some cancer risk.”
Treating and Preventing EO Exposure
There is no antidote to ethylene oxide poisoning, and treatment consists of decontamination as well as respiratory and cardiovascular support. People treating others who have been exposed should be wearing protective gear and HAZMAT teams should be contacted.
Because side effects of acute ethylene oxide exposure can occur up to 72 hours after exposure, anyone who suspects exposure should go to a medical facility for evaluation.
The Agency for Toxic Substances & Disease Registry has some guidelines for treating ethylene oxide exposure. They consist of decontamination and emergency care.
For more information, contact local, state or national poison control centers.
Before being treated for serious symptoms, anyone who has been exposed will be decontaminated. For minor contamination, rescuers will remove any contaminated clothing and wash skin and hair for 3 to 5 minutes. Eyes should be flushed with saline or water for at least 15 minutes after removing any contact lenses.
If patients are having trouble breathing, rescuers will intubate them to help them breathe. Aerosolized bronchodilators — medications that help relax the lungs and improve breathing — may be used.
People who are comatose, having seizures or exhibiting an irregular heartbeat will be rushed to the hospital and placed on advanced life support after decontamination.
Most exposure happens in the workplace. The law requires employers to make sure employees have appropriate protective gear such as protective clothing and respirators. There are also limits in place for how long a person may work around ethylene oxide.
- Wearing protective clothing
- Discarding clothing that may be contaminated
- Wearing goggles and skin protection
- Not smoking, eating or drinking while working with EO
- Seeing a doctor if you have been exposed to EO
- Avoiding working with EO without protective gear
Ethylene Oxide Lawsuits
The EPA sets limits for EO emissions. But sometimes workers or people that live near industrial facilities that produce or work with the chemical may be exposed because of uncontrolled emissions.
Because ethylene oxide gas is colorless and odorless, people might not know they are inhaling it. It can linger for as long as 149 days in the air in colder weather, according to the EPA.
People who developed cancer after being exposed to uncontrolled emissions are filing ethylene oxide lawsuits against corporations responsible for the exposure. Cancers that are a part of the lawsuits are: Breast cancer, lymphoid tumors, non-Hodgkin lymphoma, multiple myeloma and chronic lymphocytic leukemia.
13 Cited Research Articles
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