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Dioxane

1,4-Dioxane, 1,4-Diethylene dioxide

SPRI Emission Reporting Threshold
10.0 Kg/yr Pollutant Emissions to Air
Disclaimer
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?
Dioxane is a colourless liquid which has a faint, pleasant smell. It evaporates easily and is highly flammable. When heated, it gives off acrid smoke and fumes. Dioxane is insoluble, both in water and organic (carbon-containing) solvents. Dioxane is one of a group of chemicals known as the volatile organic compounds (VOCs).
What is it used for?
Large amounts of Dioxane are used in solvent applications, mainly as a stabilising agent for chlorinated solvents. It is also used in the textile industry and is an ingredient of paints, deodorants and cosmetics.
Where does it come from?
The most significant releases of Dioxane occur as spills to air or surface waters from industry producing or using it. It is also released from products containing it, such as paints. There are not thought to be any signifiant natural sources of Dioxane to the environment.
How might it affect the environment?
Once in the atmosphere Dioxane breaks down into harmless substances within hours, so releases to air are unlikely to cause environmental damage. Dioxane released to water or soil is however potentially damaging because it may leach into groundwater where it is not readily broken down. As a VOC, Dioxane can be involved in the formation of ground level ozone which can cause damage to crops and materials. The overall impact of Dioxane pollution on the global environment is unknown, although it is likely that its ability to persist in water bodies and soils may mean it can travel significant distances from the site of emission.
How might exposure to it affect human health?
Dioxane can enter the body either by inhalation of air containing dioxane vapours, ingestion of contaminated water and food, or by dermal contact with dioxane and products that contain dioxane. Inhalation of air containing dioxane vapours can cause irritation of the respiratory tract. Exposure to high concentrations can affect the central nervous system and can lead to effects including headache, dizziness, drowsiness, nausea, liver and kidney damage and coma. Ingestion of dioxane can cause a range of adverse health effects including gastrointestinal irritation, nausea, vomiting, diarrhoea and effects similar to those for inhalation. Dermal contact with dioxane may cause skin irritation. The International Agency for Research on Cancer has designated dioxane as a possible carcinogen. However, exposure to dioxane 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 Dioxane are controlled through the UK Pollution, Prevention and Control (PPC) Regulations and the UK Surface Waters (Dangerous Substances) Regulations (SI 1997/2560). European Directives concerned with releases of Dioxane include that which evaluates and controls risks associated with substances known to be in the environment (793/93/EEC); that which aims to combat air pollution from industrial plants (84/360/EEC); and the Solvents Directive (99/13/EC). At an international level, Dioxane is regulated through the UN/ECE Convention on Long-Range Transboundary Air Pollution; the Basel Convention concerning the transboundary movement and disposal of hazardous wastes; and the OSPAR Convention which is concerned with the protection of the marine environment of the north-east Atlantic Ocean.