Chemical control strategies often start by flushing bed bugs out from their hiding places by use of a natural or synthetic pyrethroid based aerosol spray. This is then followed by use of other insecticides inside the premises, including the treatment of beds and other furniture. Active ingredients approved for use against bed bugs in the UK under the Control of Pesticides Regulations 1986 (COPR) are the following organophosphates: chlorpyrifos methyl, diazinon, fenitrothion, iodofenphos, pirimiphos-methyl and trichlorfon; and carbamates, bendiocarb and propoxur. These groups of chemicals act as nerve poisons which kill by inhibiting the nerve enzymne cholinesterase which disrupts the nervous system. More than half of these actives will have their licences revoked as part of the UK Health and Safety Executive (HSE) review of all anticholinesterase compounds. This process began in September 1998 when data call-in letters were sent to approval holders. Because of lack of support the following substances chlorpyrifos-methyl, diazinon (which shows evidence of mutagenicity and evidence of embryotoxicity), iodofenphos, trichlofon and propoxur (a suspected human carcinogen) have had their licences revoked(1,2).
The synthetic pyrethroids alpha cypermethrin, bioallethrin, bioresmethrin, cypermethrin, deltamethrin, d-phenothrin, permethrin, resmethrin, s-bioallethrin, tetramethrin and the OPs trichlorphon and fenitrothion are suspected of being endocrine disruptors. Endocrine disrupting chemicals may affect the balance of normal hormonal function of animals and are suspected of contributing to the decrease in male fertility, female reproductive problems, increases in prostate and breast cancer, and behavioural and developmental problems in children(3). The German Federal Environment Agency suspects deltamethrin of affecting sperm and the placenta and dimethoate of affecting sperm and prolonging pregnancy(4).
The botanicals registered for use in the UK (pyrethrins and pyrethrum extract) are the only pesticides that are not suspected endocrine disruptors or anticholinestease compounds.
1. PAN UK Active Ingredient Database, 1999.
2. List of active ingredients that have been approved for use against bed bugs, provided by the Health and Safety Executive 13/05/99 and personal communications 10/02/2000.
3. Environmental endocrine disruptors, A handbook of property data, Keith, L. H., John Wiley and Sons, Inc., 1997, 1232pp.
4. ENDS Report 290, March 1999, p28.
Source : About.com