Uses

In the developing world where the vector-borne disease dengue fever is endemic, temephos is widely used and applied by both private and public pest control in areas of standing water where the Aedes aegypti mosquito breeds in order to reduce the population of this disease-carrying insect.Temephos is also used in the Guinea worm eradication program to kill water fleas that carry guinea worm larvae.

Resistance to temephos by A. aegypti has been seen in Brazil. The Brazilian Aedes aegypti resistance monitoring program detected temephos resistance in A. aegypti populations from several localities in the country in 1999 (Funasa 2000, Lima et al. 2003). In 1999, mosquitoes from the city of Rio de Janeiro were already resistant to temephos.

Health hazard

Temephos can be absorbed into the body by inhalation, through the skin and by ingestion. 

Effects of short-term exposure

Cholinesterase inhibition. The substance may cause effects on the nervous system. This may result in convulsions and respiratory depression. The effects may be delayed. Medical observation is indicated. Exposure far above the OEL could cause death. 

Inhalation risk

A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20°C. 

Effects of long-term or repeated exposure.

Cholinesterase inhibition. Cumulative effects are possible. 

Disposal

Filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.