Bug Bites Can Make You Sick

August 12, 2014

As summer begins to draw to a close, there are still many warm days ahead with the likelihood of “visits” from mosquitoes and ticks. These insects can carry diseases that can make humans very ill. The use of an insect repellent will help to protect you from insect bites. (The best protection is to avoid insects, but thisis not always possible!)Yet many people worry about their safety because of the chemicals they contain. Research has shown that when used correctly, these products protect against disease with little, if any, harmful effects.

To address this issue, the CT Department of Public Health (CTDPH), Environmental and Occupational Health Program has released a new fact sheet, “A Guide to Using Insect Repellents Safely” (July 2014.)  Information from the fact sheet is presented in this column. Perhaps after reading it you will feel more comfortable using insect repellents consistently. Preventing Lyme disease and other tick-related illnesses, as well as mosquito-borne illnesses (West Nile Virus and Eastern Equine Encephalitis) is well worth applying insect repellent when you are outdoors.

According to the fact sheet:

Insect repellents are generally safe IF used according to the directions and the precautions taken as stated on the label. Pay attention to the safety precautions for children. The Environmental Protection Agency (EPA) registration of the product assures that the product has been reviewed and proven to be effective and safe. Insect repellents are pesticides that must be registered by the EPA and should be used with caution. Insect repellents come in many forms including pump sprays, aerosols, lotions, creams, liquids, solids and towelettes. The active ingredients in most insect repellents are DEET, Picardin, or IR 3535, for exposed skin and permethrin, for clothing only. Read the product labels carefully to determine the: Kind of insect(s) that are repelled; Active Ingredient (main chemical); EPA registration number; and the concentration of the ingredient. Repellents containing a higher percentage of active ingredient provide longer-lasting protection. For example, to repel mosquitoes a product with a 10% concentration may last 2 hours; a 20% concentration might last 5 hours. Use the lowest concentration that will get you the protection time you need. Note: A higher concentration is often required to repel ticks than to repel mosquitoes. The EPA has a tool that you can use to determine the “Repellent that is Right for You.” It is located at http://cfpub.epa.gov/oppref/insect/

The active ingredients found in repellents include:

DEET (N,N-diethyl-meta-toluamide) repels biting pests such as mosquitoes and ticks when applied to skin or clothing. If used as directed, DEET is generally of low toxicity and considered safe by most public health agencies. However, DEET can irritate the eyes and has a pungent odor. Do not use concentrations above 30%.

Picardin repels a wide range of pests when applied directly to exposed skin but does not irritate skin or eyes, and has no odor. It is a good alternative to DEET.

IR 3535 (3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester) is effective against mosquitos, ticks and biting flies. It can be an eye irritant but is not a skin irritant. It is a good alternative to DEET.

Permethrin is a repellent and insecticide that is applied ONLY to clothing, not exposed skin. It is the ingredient used in treated clothing to repel ticks and mosquitoes. Clothes should be washed separately. These products continue to repel and kill insects after several washings. It can also be applied to outdoor equipment such as tents

Botanical (plant-based) products such as oil of lemon eucalyptus or the synthetic version (PMD) do not provide the same level of protection and may contain allergens. They have not been tested or registered by EPA. They should not be used on children under the age of three.

 The fact sheet provides information on using the insect repellent correctly:

Read and follow all directions and precautions on the product label;

  • Apply outdoors.
  • Apply to face by putting on hands first and then rubbing on face. Do not spray directly onto face.
  • Do not apply near eyes or mouth; apply only to exposed skin or outside clothing
  • Do not apply over cuts, wounds, or irritated skin.
  • Do not apply near food.
  • Use just enough repellent to cover exposed skin and/or clothing. Do not use under clothing.
  • After returning indoors, wash treated skin with soap and water or bathe. Wash treated clothing before wearing it again

 Children and Insect Repellent

  • The American Academy of Pediatrics (AAP) recommends that insect repellents not be used on infants under the age of 2 months.
  • Use a product with the lowest concentration of active ingredient that is effective for the length of time you will be out; if using DEET, keep the concentration to below 30% for children.
  • When using on children, apply to your own hands and then put it on the child. Do not apply to the hands or near eyes and mouth of young children.
  • Use netting on infant strollers and carriers.
  • Always store insect repellents safely out of the reach of children.


If you (or your child) get a rash or other reaction from a repellent, stop using the repellent, wash the repellent off with mild soap and water, and call a local poison control center for further guidance. If you go to a doctor, it might be helpful to take the repellent with you.

Repellents with a concentration of DEET over 50% have caused skin reactions, eye irritation, and blisters; concentrations over 95% may cause serious side effects such as seizures.

Other Considerations:

  • Do not use products that have insect repellent as part of sunscreen, lotions or other body products. Instead, apply sunscreen or lotion and then repellent.
  • Do not use outdoor foggers, they contain toxic ingredients; do not use candles, they can be respiratory irritants and are only mildly effective as a repellent.
  • Electronic bug zappers, treated wristbands and ultrasonic devices are ineffective.

 A copy of this guide can be obtained from the CT DPH website, or you can request a copy on line or by phone from Quinnipiack Valley Health District (QVHD), 203 248-4528 or dculligan@qvhd.org Information is also available from QVHD on reducing mosquito populations on your property.