Frequently Asked Questions

Permethrin breaks down quickly in the environment. The vapor phase reacts with sunlight to degrade the chemical within a few hours. If released to soil, permethrin is expected to have no mobility. Some will be broken down quickly as a vapor, while the remaining chemical will be absorbed by the soil and biodegraded in less than four weeks. If released into moving water, permethrin is expected to absorb to suspended solids and sediments. Degradation would occur within a few days.

Because the product is applied at very low concentrations, it is not likely to harm human health. At levels far higher than those used to control mosquitoes, permethrin can cause headaches, dizziness, nausea, vomiting, shortness of breath, or difficulty breathing. Very high doses may lead to loss of consciousness. Permethrin may make the skin and eyes redden, itch, or sting. However, the small amount used in spraying is not likely to be irritating. If you come in contact with the spray, wash your skin and clothing with soap and water.

Because mosquito control only presents a short-term exposure to very small amounts of permethrin, the EPA has concluded that its use to control mosquitoes would not present a cancer risk. Based on studies in laboratory animals, permethrin could possibly cause cancer in humans. However, the cancer occurred in animals only after being treated with very high levels of permethrin over very long periods of time.

Because the product is applied at very low concentrations, it is not likely to harm the health of adults, children, or pets. To help reduce possible contact with permethrin during spraying:

• Whenever possible, stay indoors during spraying.
• If you must go outside during spraying, wear clothing that limits skin contact with the spray.
• If you come in contact with the spray, wash your skin and clothing with soap and water.
• Wash any fruits and vegetables that were outside during spraying with water before storing, cooking or eating.
• Some individuals are sensitive to pesticides. Persons with asthma or other respiratory conditions are encouraged to stay inside during spraying since there is a possibility that spraying could worsen these conditions.
• Anyone experiencing adverse reactions to pesticides should seek medical care or call 911.
• Talk to your doctor if you have major health concerns.

It is recommended that you use products containing DEET (N,N-diethyl-m-toluamide). EPA has a search tool on their website that can help you search for a repellent that is right for you. Visit http://cfpub.epa.gov/oppref/insect/.

Because the product is applied at very low concentrations when spraying for mosquitoes, it is not likely to harm the health of pets, even if they are outside during spraying. As a precaution, pet owners are advised to remove pets, along with their food and water bowls, from outdoor areas during spraying if spraying occurs in their neighborhood.

Although the vast majority of infections have been identified in birds, WNV has been shown to infect dogs, cats, and horses. For more information, visit the CDC website.

Because the product is applied at very low concentrations, it is not likely to harm the health of livestock when used according to the label.

The amount of permethrin that is likely to enter an outdoor pond or any other body of water after spraying is very low. Therefore, it is not likely to harm the fish in your outdoor pond. At higher levels, permethrin can be toxic to fish. If you wish to reduce exposure, you can cover your fishponds with a tarp before spraying. Do not leave tarps on long enough to cause overheating or a decrease in oxygen. Some people may prefer to bring their fish to a tank inside.

Yes, permethrin is highly toxic to bees. Spraying will be performed between 9 p.m. until 5 a.m. During this time, the bees should be in their hive. However, it is recommended that beekeepers take steps to protect their colonies on nights when spraying is taking place. Practical methods include moving hives out of the treated area or covering hives with loose fabric, like wetted burlap, to keep the bees in the hive and protect them from drift. Wild bees generally nest in protected locations and should be mostly protected because they are in the nest when sprays are applied at night. Although the full impact of mosquito applications on honey bees and other wild bee pollinators is unknown, wild pollinator populations would not be expected to be harmed for long-term after sprays are discontinued.

Since permethrin droplets are designed to stay airborne for an extended period, little permethrin is expected to settle into your pool. If any permethrin does enter your pool, the water would quickly degrade it. If you choose, you can cover your pool before the spraying occurs. You do not need to take special steps or wait before you can use your pool again.