That leaves many consumers with the burning question: Which method is the best when it comes to fending off these annoying and sometimes dangerous adversaries?
There's no shortage of products on the market, from sprays to wipes to lotions, but it's the active ingredient -- rather than the delivery system -- you need to focus on. Although people have been burning citronella candles since the late 19th century, there's little evidence they're any more effective than regular candles, and the Environmental Protection Agency says only citronella applied directly to the skin offers "some protection in certain circumstances."
Similarly, those bug zappers that crackle and pop as they electrocute flying insects are useless when it comes to controlling mosquitoes. And how about those ultrasonic devices that you place on a table or wear on your belt? The Centers for Disease Control and Protection (CDC) says these "devices are NOT effective in preventing mosquito bites." One ultrasonic mosquito repellent manufacturer, Lentek International, was charged by the Federal Trade Commission for making false and unsubstantiated claims about their product.
So what does work?
The CDC recommends insect repellents whose effectiveness has been proven in scientific trials and contain active ingredients which have been registered with the EPA for use on skin or clothing. When the EPA registers a repellent, the agency evaluates the product for its performance and absence of "unreasonable adverse effects" on human beings and the environment.
Of all the active ingredients registered with the EPA, the CDC says two have "demonstrated a higher degree of efficacy" in the scientific literature, and typically provide longer-lasting protection than others in repelling mosquitoes. A third, made from natural sources, also is recommended.
The recommended repellent ingredients are:
- DEET: Developed by the U.S. Army in response to jungle warfare during World War II, DEET has been commercially available since 1957, and remains the most common active ingredient used in insect repellents. It is most effective when applied on skin and can damage certain types of fabrics. It repels biting pests such as mosquitoes and ticks, including those that carry Lyme disease. DEET-based products include a variety of liquids, lotions, sprays, and impregnated materials, such as wristbands. Repellents can contain anywhere from 4% to 100% DEET. The American Academy of Pediatrics recommends products used on children contain 30% or less DEET. All the major repellent brands -- including Off!, Cutter and Repel -- use DEET. Another tip: The CDC says to avoid using a sunscreen that contains DEET, but rather to apply sunscreen and then the repellent.
- Picaridin (also known as Icaridin): a colorless, nearly odorless liquid active ingredient that is used as an insect repellent against biting flies, mosquitoes, chiggers, and ticks. It should be applied to clothing, not skin. Picaridin products were sold in Europe and Australia for several years before being introduced to the U.S. market in 2005. Picaridin–based products usually contain 5% to 20% of the active ingredient. Picaridin is a common ingredient in many of the repellents marketed as an alternative to DEET. Cutter carries an entire line, from wipes to aerosols to sprays. A variety of other brands including Natrapel and Avon use Picaridin, which you'll also find in Off!'s Family Care II line. The regular line is made with DEET.
- Oil of Lemon Eucalyptus: In two recent scientific publications, when oil of lemon eucalyptus -- which is derived from natural materials -- was tested against mosquitoes, it provided protection similar to repellents with low concentrations of DEET. Cutter and Repel each sell pump bottles that spray repellents made with lemon eucalyptus oil.
Confused about which product to choose? The EPA offers a useful tool that allows consumers to search for repellents based on insect, protection time, active ingredient and other information. All the results are EPA-approved products and allow you to fine-tune your search to a remarkable degree.
For instance, looking for any kind of repellent that will keep mosquitoes at bay for 12 hours? The search tool offers 50 products to choose from. Try it out for yourself.