Insect Repellents

 

e-Medical Note:

Length of protection from mosquito bites varies with the amount of active ingredient, ambient temperature, amount of physical activity/perspiration, any water exposure, abrasive removal and other factors. 

  • Choose a repellent that you will be likely to use consistently. 

  • Always choose a repellent that provides sufficient protection for the amount of time that you will be outdoors. Product labels often indicate the length of time that you can expect protection from a product.

For long duration protection use a long lasting (micro-encapsulated) formula and re-apply as necessary, according to label instructions.

  • How often should you re-apply insect repellents?:

  • Follow the directions on the product you are using.

  • Sweating or getting wet may mean that you need to re-apply more frequently. 

  • Repellents with a higher concentration of active ingredient (such as DEET) provide longer-lasting protection.

In addition to wearing repellent, you can protect yourself and your family by taking these precautions:

  • Wear clothing with long pants and long sleeves while outdoors. 

  • Apply DEET or other repellents such as permethrin to clothing, as mosquitoes may bite through thin fabric. (Remember: don't use permethrin on skin) 

  • Use mosquito netting over infant carriers. 

  • Reduce the number of mosquitoes in your area by getting rid of containers with standing water that provide breeding places for the mosquitoes.

How to Choose & Use Insect Repellents

Mosquitoes, biting flies, and ticks can be annoying and sometimes pose a serious risk to public health. In certain areas of the United States, mosquitoes can transmit diseases like equine, West Nile Virus, and St. Louis encephalitis. Biting flies can inflict a painful bite that can persist for days, swell, and become infected. Ticks can transmit serious diseases like Lyme disease, West Nile Virus, and Rocky Mountain spotted fever. When properly used, insect repellents can discourage biting insects from landing on treated skin or clothing.

Why You Should Use Mosquito Repellent

Insect repellent helps reduce your exposure to mosquito bites that may carry West Nile virus or other diseases, and allows you to continue to play, work, and enjoy the outdoors with a lower risk of disease.

When Should you Use Mosquito Repellent

Use repellent when you go outdoors. You should use repellent even if you're only going outside for a few minutes. Many of the mosquitoes that carry the West Nile virus bite between dusk and dawn. If you're outside during these hours pay special attention to using repellent.

Choosing Insect Repellents

Insect repellents are available in various forms and concentrations. Aerosol and pump-spray products are intended for skin applications as well as for treating clothing. Liquid, cream, lotion, spray, and stick products enable direct skin application. Products with a low concentration of active ingredient may be appropriate for situations where exposure to insects is minimal. Higher concentration of active ingredient may be useful in highly infested areas or with insect species which are more difficult to repel. And where appropriate, consider nonchemical ways to deter biting insects - screens, netting, long sleeves, and slacks.

Recommendations for Types of Repellents: DEET, Picaridin, etc.

A wide variety of insect repellent products are available. Medical authorities recommend the use of products containing active ingredients which have been registered with the government agencies for use as repellents applied to skin and clothing. In the U.S.A., EPA registration of repellent active ingredients indicates the materials have been reviewed and approved for efficacy and human safety when applied according to the instructions on the label.

Of the active ingredients registered with the EPA, DEET and Picaridin have demonstrated a higher degree of efficacy in the peer-reviewed, scientific literature. Products containing these 2  active ingredients typically provide longer-lasting protection than others.

1. DEET

How the Percentage of DEET in a Product Relates to Protection Time: A recent study indicates the following:

A product containing 23.8% DEET provided an average of 5 hours of protection from mosquito bites. A product containing 20% DEET provided almost 4 hours of protection. A product with 6.65% DEET provided almost 2 hours of protection. Products with 4.75% DEET and 2% soybean oil were both able to provide roughly 90 minutes of protection.

You should use a higher percentage of DEET if you will be outdoors for several hours. You can use a lower percentage of DEET if time outdoors will be limited. You can also re-apply a product if you are outdoors for a longer time than expected and start to be bitten by mosquitoes.

Repellent products that do not contain DEET are not likely to offer the same degree of protection from mosquito bites as products containing DEET. Non-DEET repellents have not necessarily been as thoroughly studied as DEET, and may not be safe for use on children.

Instructions for Use:

Always follow the recommendations appearing on the product label when using repellent.

When using repellent on a child, apply it to your own hands and then rub them on your child. Avoid children's eyes and mouth and use it sparingly around their ears. Do not apply repellent to children's hands. (Children may put their hands in their mouths.) Do not allow young children to apply insect repellent to themselves; have an adult do it for them. Keep repellents out of reach of children. Do not apply repellent to skin under clothing. If repellent is applied to clothing, wash treated clothing before wearing again.

Is DEET use safe for Pregnant or Nursing Women?

There are no reported adverse events following use of repellents containing DEET in pregnant or breastfeeding women.

Are Products Containing DEET Safe for Children?:

DEET products can be used safely on children. The American Academy of Pediatrics (AAP) Committee on Environmental Health has recently cited: "Insect repellents containing DEET with a concentration of 10% appear to be as safe as products with a concentration of 30% when used according to the directions on the product labels."

The AAP and other experts suggest using repellent with low concentrations of DEET on infants over 2 months old. Other guidelines suggest using repellents containing DEET after children are 2 years of age.

2. Other repellents:

  • Picaridin (KBR 3023) 

  • Oil of lemon eucalyptus [p-menthane 3,8-diol (PMD): A plant based repellent, is also a registered and effective product. In two recent scientific publications, when oil of lemon eucalyptus was tested against mosquitoes found in the US, it provided protection similar to repellents with low concentrations of DEET.

Oil of lemon eucalyptus has not been tested against mosquitoes that spread malaria and some other diseases which occur internationally.

  • Products which contain permethrin are recommended for use on clothing, shoes, bed nets and camping gear and are registered products. 

Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes and other arthropods and retains this effect after repeated laundering. The permethrin insecticide should be reapplied following the label instructions. Some commercial products are available pretreated with permethrin.

Alternative Repellents:

  • Garlic: The garlic we eat goes to our skin & repells mosquitos - this measure helps but is not so effective.

  • Lavender & Eucaliptus placed in cotton or on clothes help keep mosquitos away.