SPRI Home About SPRI

Ethylene oxide

1,2-Epoxyethane, Oxirane, Amproline

SPRI Emission Reporting Threshold
1,000 Kg/yr Pollutant Emissions to Air
1.00 Kg/yr Pollutant Emissions to Water
1.00 Kg/yr Pollutant Emissions to Waste Water
10.0 Kg/yr Pollutant Emissions to Land
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
Under normal conditions, Ethylene oxide is a colourless gas, which has no detectable smell. It is very reactive and highly flammable. Ethylene oxide is very soluble in water and most organic (carbon-containing) solvents.
What is it used for?
Because of its highly reactive nature, Ethylene oxide is widely used in the chemical industry to produce a variety of important products. These include antifreeze, plastics used for photographic film, fibres for textiles, cosmetics, pharmaceuticals, brake fluid, lubricants, solvents, heat transfer agents and cleaning or sterilising agents.
Where does it come from?
The most significant releases of Ethylene oxide occur from industry producing or using it, particularly where it is used for cleaning or sterilising purposes. Relatively much smaller amounts are released naturally from volcanoes and from living organisms.
How might it affect the environment?
Typically low environmental levels of Ethylene oxide are unlikely to harm the environment or wildlife. However, Ethylene oxide is toxic and exposure to high levels may cause significant harm, particularly to aquatic organisms. Ethylene oxide does not accumulate in the environment, but its breakdown in air and water is fairly slow. As a VOC, it may be involved in the formation of ground level of ozone, which can damage crops and materials. However, Ethylene oxide is thought to be generally only slightly involved in this reaction. It is not considered likely that Ethylene oxide pollution has any effects on the global environment.
How might exposure to it affect human health?
Ethylene oxide exposure mainly occurs in the occupational setting and can enter the body either by inhalation of air containing ethylene oxide or by accidental ingestion of, or dermal contact with, ethylene oxide. Inhalation of air containing low levels of ethylene oxide over long periods of time can cause irritation of the eyes, skin and respiratory passages. Exposure to ethylene oxide affects the nervous system and can lead to headaches, memory loss and numbness. Exposure may also increase the rate of miscarriage. Higher level exposure may result in similar but more severe effects. Ingestion of ethylene oxide can lead to nausea, vomiting and diarrhoea. Dermal contact with ethylene oxide can cause severe skin burns. The International Agency for Research on Cancer has designated ethylene oxide as a carcinogen. However, exposure to ethylene oxide at normal background levels is unlikely to have any adverse effect on human health.
What steps are being taken to limit the potential impacts?
Releases of Ethylene oxide are regulated through the UK Pollution, Prevention and Control (PPC) Regulations. As a VOC, levels of Ethylene oxide in air are also controlled through the UK National Air Quality Strategy. It is also regulated through the European Directive concerned with pollution of the aquatic environment (76/464/EEC) and that concerned with the marketing and use of certain dangerous chemicals (79/117/EEC). The main international legislation regulating levels of VOCs such as Ethylene oxide is the UN/ECE Convention on Long-Range Transboundary Air Pollution and the Basel Convention on the transboundary movement and disposal of hazardous wastes.