Phenothrin, also called sumithrin and d-phenothrin, is a synthetic pyrethroid that kills adult fleas and ticks. It has also been used to kill head lice in humans. d-Phenothrin is used as a component of aerosol insecticides for domestic use. It is often used with methoprene, an insect growth regulator that interrupts the insect's biological lifecycle by killing the eggs.

Effects

Phenothrin is primarily used to kill fleas and ticks. It is also used to kill head lice in humans, but studies conducted in Paris and the United Kingdom have shown widespread resistance to phenothrin. It is extremely toxic to bees. A U.S. Environmental Protection Agency (EPA) study found that 0.07 micrograms were enough to kill honey bees. It is also extremely toxic to aquatic life with a study showing concentrations of 0.03 ppb killing mysid shrimp. It has increased risk of liver cancer in rats and mice in long-term exposure, with doses in the range of 100 milligrams per kilogram of body weight per day, or above. It is capable of killing mosquitoes, although remains poisonous to cats and dogs, with seizures and deaths being reported due to poisoning. Specific data on concentrations or exposure are lacking. Phenothrin has been found to possess antiandrogen properties, and was responsible for a small epidemic of gynecomastia via isolated environmental exposure. The EPA has not assessed its effect on cancer in humans. However, one study performed by the

Mount Sinai School of Medicine The Icahn School of Medicine at Mount Sinai (ISMMS or Mount Sinai), formerly the Mount Sinai School of Medicine, is a private medical school in New York City. It is the academic teaching arm of the Mount Sinai Health System, which manages eigh ...

linked sumithrin with breast cancer; the link made by its effect on increasing the expression of a gene responsible for mammary tissue proliferation.

EPA action

In 2005, the U.S. EPA cancelled permission to use phenothrin in several flea and tick products, at the request of the manufacturer, Hartz Mountain Industries. The products were linked to a range of adverse reactions, including hair loss, salivation,

tremor A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, fa ...

s, and numerous deaths in cats and kittens. In the short term, the agreement called for new warning labels on the products. As of March 31, 2006, the sale and distribution of Hartz's phenothrin-containing flea and tick products for cats has been terminated. However, EPA's product cancellation order did not apply to Hartz flea and tick products for dogs, and Hartz continues to produce many of its flea and tick products for dogs. See also "dog" in the following EPA ruling:

References

External links

d-Phenothrin general information
– National Pesticide Information Center
Pyrethrins and Pyrethroids Fact Sheet – National Pesticide Information Center

* {{Human lice Chrysanthemate esters Endocrine disruptors Nonsteroidal antiandrogens Pest control (3-phenoxyphenyl)methyl 2,2,3-trimethylcyclopropane-1-carboxylates