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Dichlorvos

2,2-Dichlorovinyl dimethyl phosphate, DDVP, Vapona, Cyanophos

SPRI Emission Reporting Threshold
10.0 Kg/yr Pollutant Emissions to Air
0.0005 Kg/yr Pollutant Emissions to Water
0.0005 Kg/yr Pollutant Emissions to Waste Water
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?
Under normal conditions, Dichlorvos is a pale orange coloured liquid, which has a sweet, pleasant smell. It boils at 35 degrees celsius and evaporates fairly easily at room temperature. It is non-flammable, but will corrode some metals. Dichlorvos dissolves well in water and also in most organic (carbon-containing) solvents. Dichlorvos is one of a group of chemicals known as the "organophosphorus pesticides".
What is it used for?
Dichlorvos has been widely used as an insecticide to control pests in stored food and in greenhouses, to control insects in domestic and public buildings and to control parasites on livestock and pets. The way in which Dichlorvos works is similar to the action of chemicals used to make "nerve gas" during the second world war.
Where does it come from?
The most significant releases of Dichlorvos will occur to the atmosphere and to surface waters as a result of its application as an insecticide. Other releases may occur during its manufacture, transport and storage. There are not thought to be any natural sources of Dichlorvos to the environment.
How might it affect the environment?
Dichlorvos is very toxic to aquatic organisms and moderately toxic to non-target insects such as bees. There is also some concern that it may interfere with the hormone systems - that it is an "endocrine disruptor". However, it does not persist in the environment. It evaporates easily into the atmosphere where it is broken down into harmless chemicals in a matter of days. In soils, it breaks down within a few weeks. Although it can seep into groundwaters, it does not bind significantly to sediments and will break down within weeks. Dichlorvos does not accumulate in the environment. Negative impacts associated with exposure to Dichlorvos are only likely in the vicinity of its release. It is not considered likely that Dichlorvos pollution has any effects on the global environment.
How might exposure to it affect human health?
Dichlorvos exposure occurs mainly in the occupational setting. Dichlorvos enters the body mainly by inhalation of air containing dichlorvos but can also enter by ingestion of contaminated water or food or by dermal contact with dichlorvos. Inhalation of air containing high levels of dichlorvos can result in a range of adverse health effects such as nausea, anxiety, restlessness, teary eyes, profuse sweating, muscle tremors, slurred speech, seizures, breathing difficulties and in extreme cases inability to breathe, coma and death. Ingestion of dichlorvos can cause vomiting, diarrhoea, abdominal pain and symptoms similar to those for inhalation. Dermal contact with dichlorvos may result in profuse sweating. Absorption of high levels of dichlorvos through the skin can lead to similar effects as those for inhalation. The International Agency for Research on Cancer has designated dichlorvos as a possible carcinogen. However, exposure to dichlorvos at normal background levels is unlikely to have any adverse effect on human health.
What steps are being taken to limit the potential impacts?
Dichlorvos is a UK "red list" pollutant, signifying that its presence in the environment is of particular concern. Releases of Dichlorvos are controlled through the Food and Environmental Protection Act (FEPA 1985) and the Control of Pesticides Regulations (COPR 1986). Dichlorvos is also regulated through the UK Pollution, Prevention and Control (PPC) Regulations and the UK Surface Waters (Dangerous Substances) Regulations (SI 1997/2560). At a European level, it is controlled through the European Directive concerned with pollution of the aquatic environment (76/464/EEC). Internationally, it is listed as a candidate substance for inclusion in the OSPAR and Helsinki Conventions which protect the marine environments of the north-east Atlantic Ocean and Baltic Sea respectively.