Permethrin Facts
NPIC National Pesticide Information Center
Laboratory Testing
Before pesticides are registered by the U.S. EPA they must undergo laboratory testing for short-term (acute) and long-term (chronic) health effects. These tests help scientists judge how the chemicals might affect humans, domestic animals and wildlife in cases of overexposure.
Uses of Permethrin
Permethrin is an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower. Permethrin is used in a number of ways to control insects. Products containing permethrin may be used in public health mosquito control programs. They may be used on food and feed crops, on ornamental lawns, on livestock and pets, in structures and buildings. Permethrin may also be used in places where food is handled, such as restaurants. Permethrin can also be used in numerous residential sites, both indoor and outdoor, and on pets and clothing.
There are currently more than 1400 registered products containing permethrin. Some products are used to treat scabies and head lice on people. These products are drugs and are regulated by the U.S. Food and Drug Administration (FDA). *see exhibit A
Permethrin and Mosquito Nets
CDC: According to the Centers for Disease Control and Prevention (CDC) only pyrethroid insecticides are approved for use on Insecticide-treated nets (ITNs.) These insecticides have been shown to pose very low health risks to humans and other mammals, but are toxic to insects and kill them, even at very low doses. In community-wide trials in several African settings, ITNs have been shown to reduce the death of children under 5 years from all causes by about 20%.
WHO: The World Health Organization (WHO) has issued a guidance for the use of insecticide-treated mosquito nets to protect people from malaria. The WHO Pesticide Evaluation Scheme (WHOPES) has given either full or interim approval to a number of Long-Lasting Insecticide Treated Nets (LLIN) for use in the prevention of malaria.
LLINs have been associated with sharp decreases in malaria in countries where malaria programs have achieved high LLIN coverage. WHO now recommends that LLINs be distributed to and used by all people (“universal coverage”) in malarious areas, not just by the most vulnerable groups: pregnant women and children under 5 years.
Exhibit A
Safety for Humans
A study was conducted involving 196 women who had applied a single, full-body, dermal dose of 4% permethrin as a scabies treatment during their second or third trimesters of pregnancy. Researchers found no evidence that exposure to permethrin affected the outcome of the participants pregnancies.
A study involving 113 women using a 1% permethrin head lice during pregnancy found no indication that exposure to permethrin affected the outcome of their pregnancies.
While children may be especially sensitive to pesticides compared to adults, there are currently no data to suggest that children have increased sensitivity specifically to permethrin.