Ethylene oxide: general information
Updated 10 January 2022
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This publication is available at https://www.gov.uk/government/publications/ethylene-oxide-properties-and-incident-management/ethylene-oxide-general-information
Overview
Ethylene oxide is an extremely flammable, colourless gas with a sweet odour.
Uses of ethylene oxide
Ethylene oxide is used as a chemical intermediate in the production of various products including antifreeze, detergents, fibres and bottles. It is also one of the most used sterilisation methods in the healthcare industry.
Devices that are sterilised with ethylene oxide include wound dressings, lateral flow devices and specialised devices that are used inside the body. In the past, ethylene oxide was also used as an insecticide.
How ethylene oxide gets into the environment
The majority of ethylene oxide released into the environment is from industries that produce or use it. Natural sources of ethylene oxide in the environment are volcanoes, waterlogged soil, manure and sewage.
Exposure to ethylene oxide
Exposure for the general public may occur by breathing in air contaminated with ethylene oxide or from cigarette smoking.
Exposure to ethylene oxide is more likely to occur in an occupational setting. Safe levels are enforced to protect the health of workers. Such levels are below those that are thought to cause harmful effects.
Exposure to ethylene oxide from medical devices
Any traces of ethylene oxide remaining in medical devices (for example lateral flow devices) after sterilisation are below limits that would be considered hazardous to health and comply with international standards.
How exposure to ethylene oxide can affect your health
The presence of ethylene oxide in the environment does not always lead to exposure. In order for it to cause any adverse health effects you must come into contact with it. You may be exposed to ethylene oxide by breathing or drinking the substance, or by skin contact with it. Following exposure to any chemical, the adverse health effects you may encounter depend on several factors, including the amount to which you are exposed (dose), the way you are exposed, the duration of exposure, the form of the chemical and if you were exposed to any other chemicals.
Inhalation of ethylene oxide can cause irritation of the eyes and nose, coughing, burning sensation in the mouth and breathlessness. In severe cases lung damage can occur. Ethylene oxide can be absorbed into the body via inhalation or skin contact causing headache, stomach upset, fitting, coma and heart problems. Skin contact also causes redness, blistering, ulceration and allergic contact dermatitis. Eye contact with ethylene oxide can cause irritation and inflammation.
Ingestion of liquefied ethylene oxide can cause stomach upset and pain.
Ethylene oxide and cancer
The International Agency for Research on Cancer (IARC) has classified ethylene oxide as being able to cause cancer in humans.
Short-term exposure to ethylene oxide is likely to be associated with only a very small increase in the risk of cancer.
Pregnancy and the unborn child
There is some evidence to suggest that ethylene oxide may be toxic to the reproductive system and the unborn child.
The trace amounts of ethylene oxide remaining in medical devices (for example lateral flow devices) after sterilisation would not be expected to harm the unborn child or be toxic to the reproductive system.
Children
Children exposed to ethylene oxide would be expected to display similar effects to those seen in exposed adults.
What to do if you are exposed to ethylene oxide
Exposure to traces of ethylene oxide remaining in medical devices (for example lateral flow devices) after sterilisation would not be expected to cause any adverse health effects.
If you have any health concerns regarding exposure to ethylene oxide seek guidance from your GP or contact NHS 111.
Additional sources of information
UKTIS Best Use of Medicines in Pregnancy
NHS.UK has more information on poisoning.
MHRA Information on medical devices
The information contained in this document from the UKHSA Radiation, Chemicals and Environment Directorate is correct at the time of its publication.
Email chemcompendium@phe.gov.uk or enquiries@ukhsa.gov.uk if you have any questions about this guidance.