Dichlorvos or 2,2-dichlorovinyl dimethyl phosphate (Trade Names: DDVP, Vapona, etc.) is a highly volatile organophosphate, widely used as an organophosphorus insecticide to control household pests, in public health, and protecting stored product from insects. It is effective against mushroom flies, aphids, spider mites, caterpillars, thrips, and whiteflies in greenhouse, outdoor fruit, and vegetable crops. It is also used in the milling and grain handling industries and to treat a variety of parasitic worm infections in dogs, livestock, and humans. It is fed to livestock to control bot fly larvae in the manure. It acts against insects as both a contact and a stomach poison. It is available as an aerosol and soluble concentrate. It is also used in pet collars and "no-pest strips" as pesticide-impregnated plastic. In this form it has recently been labeled for use against bed bugs.
The United States Environmental Protection Agency first considered a ban on DDVP in 1981. Since then it has been close to being banned on several occasions, but continues to be available. Major concerns are over acute and chronic toxicity. There is no conclusive evidence of carcinogenicity to date, however a 2010 study found that each 10-fold increase in urinary concentration of organophosphate metabolites was associated with a 55% to 72% increase in the odds of ADHD in children.
Dichlorvos is absorbed through all routes of exposure. Since it is an acetylcholinesterase inhibitor, its overdose symptoms are weakness, headache, tightness in chest, blurred vision, salivation, sweating, nausea, vomiting, diarrhea, and abdominal cramps.
^Espeland M., Irestedt M., Johanson K. A., Åkerlund M., Bergh J.-E. & Källersjö M. (2010). "Dichlorvos exposure impedes extraction and amplification of DNA from insects in museum collections". Frontiers in Zoology 2010, 7: 2. doi:10.1186/1742-9994-7-2