How Bug Spray Works

Posted by

Home Improvement

Bugs are everywhere, and they outnumber us by a lot. While we can’t hope to get rid of them entirely, bug spray can help keep them away. There are two main types of bug sprays: insecticides and repellents. Insecticides are designed to kill bugs on the spot or reduce their numbers over time, while repellents work by making us less attractive to bugs. Most bug sprays we use on our bodies act as repellents, while those used to keep bugs out of our homes may be either repellents or insecticides. Some bug sprays are effective against many different types of insects, while others only work on specific species. The active ingredients in bug sprays can be complex, but most household bug sprays contain one or more insecticides in the pyrethroid family. These synthetic chemicals mimic the natural oils found in chrysanthemum flowers and affect an insect’s nervous system, causing tremors, paralysis, and death. While pyrethroids are effective against many types of insects, they can also be harmful to beneficial bugs like bees and butterflies, as well as fish.

Pyrethroids, including permethrin, prallethrin, and cypermethrin, are commonly used in sprays to eliminate wasps, hornets, ants, roaches, silverfish, fleas, and ticks. It is best to spray in the evening when these insects are less active to avoid being attacked and to increase the effectiveness of the spray. Ant and roach sprays usually contain piperonyl butoxide to prevent the insecticide ingredients from degrading before they can work. Household flea and tick sprays use pyrethroids to kill adult fleas and ticks, piperonyl butoxide to extend the life of the insecticide ingredients, and a growth inhibitor like pyriproxifen to prevent new eggs and larvae from developing. However, neonicotinoids, a class of insecticides used by commercial farmers and backyard gardeners, have been linked to colony collapse disorder and the decline in the population of honeybees and other pollinators. To help protect bees, products containing neonicotinoids now have a “bee advisory box” on the label. Instead of killing bugs, repellent sprays make us invisible or unattractive to insects like mosquitoes, ticks, biting flies, and chiggers, encasing us in our own temporary protective barrier. It is recommended to use insect repellents that have been registered with the EPA and contain only the following active ingredients: picaridin, IR3535, DEET, oil of lemon eucalyptus, or para-menthane-diol.

The CDC recommends using products containing DEET, picaridin, IR3535, and oil of lemon eucalyptus to protect against mosquitoes and other bugs. DEET is the most commonly used active ingredient in bug repellents, but picaridin, found in brands like Sawyer and Natrapel, is also effective. IR3535 is a proprietary formulation of the amino acid alanine found in Avon Skin-So-Soft products. Other EPA-approved bug repellents contain natural ingredients like cedar oil, geranium oil, peppermint oil, and citronella oil, but their effectiveness has not been tested. All skin-applied bug repellents approved by or registered with the EPA have been evaluated for safety and pose minimal risk to human health. DEET is controversial, but the EPA has determined that it is safe for use on children with no age restriction. The AAP recommends DEET concentrations between 10 and 30 percent for children older than two months. Oil of lemon eucalyptus should not be used on children younger than three years old.

Household bug sprays are not meant to be used on skin, but rather on insects and floors. However, their safety to humans, pets, and the environment is still a concern. Bug sprays that are designed for indoor use may have fragrances that cover up their chemical smells, but they are not suitable for use on skin. Additionally, they should not be used near food, children, or pets. Exposure to certain pyrethroid insecticides, such as cypermethrin, has been known to cause various symptoms in animals and humans, including tremors, convulsions, dizziness, and itching.

Traps, gels, baits, or granules that insects carry back to their colonies are more effective in controlling indoor pests like ants and roaches. These methods are also less likely to be inhaled by humans.

For those concerned about the ingredients in conventional household bug sprays, products containing d-Limonene can be a natural alternative. D-Limonene, derived from citrus oils, kills insects on contact by destroying the coating of their respiratory systems and also works as a repellent.

To learn more about bug sprays and their effectiveness, visit the EPA and CDC websites. Despite the risks associated with bug bites, some people are more concerned about the possible effects of DEET than the bites themselves. Globally, mosquitoes are a significant concern and cause an estimated 600,000 deaths annually due to malaria.

Other Relevant Articles

  • The Science of DEET
  • How Mosquito Traps Work
  • Understanding Bug Zappers
  • How Insect-Repellent Clothing Works
  • Inside the World of Mosquitoes
  • How Ticks Affect Humans

Sources of Information

  • American Academy of Pediatrics. “2014 Summer Safety Tips.” (July 17, 2014)
  • Borel, Brooke. “Does your insect repellent repel insects?” May 14, 2013. (July 17, 2014)
  • Consumer Reports. “How safe are indoor bug sprays?” June 14, 2014. (July 17, 2014)
  • Doctors Foster and Smith. “Pyriproxyfen (Nylar).” (July 17, 2014)
  • Gates, Bill. “The Deadliest Animal in the World.” Gates Notes. April 25, 2014. (July 17, 2014)
  • The Hartz Mountain Corporation. “HartzĀ® UltraGuard PlusĀ® Flea & Tick Home Spray.” (July 17, 2014)
  • HHMI. “How DEET Swats Insects’ Sense of Smell.” HHMI News. Sept. 21, 2011. (July 17, 2014)
  • Huss, Karen. “Less Toxic Pesticides.” Clemson Cooperative Extension. August 2005. (July 15, 2014)
  • National Pesticide Information Center. “Cypermethrin.” Oregon State University. (July 14, 2014)
  • National Pesticide Information Center. “Permethrin General Fact Sheet.” Oregon State University. July 2009. (July 14, 2014)
  • National Pesticide Information Center. “Piperonyl Butoxide.” Oregon State University. (July 14, 2014)
  • S.C. Johnson & Son, Inc. “Raid Product Selector.” (July 17, 2014)
  • Smithsonian Institute Department of Systematic Biology, Entomology Section. “Bug Info: Numbers of Insects (Species and Individuals).” (July 14, 2014)
  • Texas A&M AgriLife Extension. “What is a neonicotinoid?” (July 15, 2014)
  • U.S. Department of Health and Human Services Household Products Database. (July 14, 2014)
  • U.S. Environmental Protection Agency. “DEET.” July 15, 2014. (July 17, 2014)
  • U.S. Environmental Protection Agency. “Find the Insect Repellent that is right for you.” (July 14, 2014)
  • U.S. Environmental Protection Agency. “Insecticides.” (July 14, 2014)
  • U.S. Environmental Protection Agency. “New Pesticide Labels Will Better Protect Bees and Other Pollinators.” August 15, 2013. (July 15, 2014)
  • U.S. Environmental Protection Agency. “Regulation of Skin-Applied Repellents.” (July 15, 2014)
  • U.S. Environmental Protection Agency. “Repellency Awareness Graphic.” (July 18, 2014)
  • U.S. Environmental Protection Agency. “Skin-Applied Repellent Ingredients.” July 15, 2014. (July 17, 2014)
  • U.S. Environmental Protection Agency. “Using Insect Repellents Safely and Effectively.” (July 17, 2014)


1. What is bug spray and how does it work?

Bug spray is a type of insecticide that is designed to kill or repel insects. It typically contains a combination of chemicals that are toxic to insects, such as pyrethroids or neonicotinoids. When insects come into contact with the spray, the chemicals penetrate their nervous system and disrupt their normal bodily functions, leading to paralysis and eventual death.

2. Are bug sprays safe to use around humans and pets?

Most bug sprays are safe to use around humans and pets when used as directed. However, it is important to read the label carefully and follow all instructions. Some sprays may be more toxic than others, and certain chemicals may cause irritation or allergic reactions in some people or pets. It is also important to avoid inhaling the spray or getting it in your eyes, nose, or mouth.

3. How should bug spray be applied?

Bug spray should be applied according to the instructions on the label. In general, it is best to spray the product directly onto the insects or their nests, rather than spraying it into the air or on surfaces. It may also be helpful to wear gloves and protective clothing, especially if applying the spray to a large area. After using bug spray, be sure to wash your hands thoroughly with soap and water.

4. What are some alternatives to bug spray?

There are several alternatives to bug spray that may be more environmentally friendly or safer for certain individuals. Some examples include using natural repellents like citronella or eucalyptus oil, wearing long sleeves and pants to avoid bites, using mosquito nets or screens, and removing standing water where mosquitoes breed. It is important to note that these alternatives may not be as effective as bug sprays and may require more frequent application or maintenance.

5. Are there any precautions to take when using bug spray?

Yes, there are several precautions to take when using bug spray. First, it is important to keep the spray out of reach of children and pets. Second, avoid spraying near food or food preparation areas. Third, do not spray near open flames or heat sources. Fourth, be sure to store the spray in a cool, dry place away from direct sunlight. Finally, if you experience any adverse reactions or symptoms after using bug spray, seek medical attention immediately.

Leave a Reply

Your email address will not be published. Required fields are marked *