It is fairly common to reach for the Off! during those sweltering, bug-infested days of summer. The smell alone is right up there with roasted peanuts and Banana Boat sunscreen in terms of synonymity of Summer. But just how safe are bug sprays during the pregnancy months? The answer is really based in what kind you use and how much.

First, you have to remember that a number of bug bites are more than simple annoyances. Insects can carry a variety of diseases, including West Nile Virus, Lyme disease and Rocky Mountain spotted fever. On the other hand, it’s also known that most pesticides are chemical poisons — and the less exposure you have, the better.

Secondly, you need to pay attention the ingredients in your bug repellent and be aware of the risks involved. There are essentially two types of repellents on the market; pesticides and biopesticides.

Repellents that contain such nonchemical (or bio chemical) ingredients as citrus, citronella and chrysanthemum are relatively safe. In fact, these biopesticides are derived from such natural materials as animals, plants, bacteria, and certain minerals. At the end of 2010, there were approximately 205 registered biopesticide active ingredients and 910 products.

  • Oil of Lemon Eucalyptus is found naturally in eucalyptus leaves and twigs. It was first registered in 1948 as an insecticide and miticide (kills insects and mites) and today is found in both lotion and spray insect repellents.
  • p-Mentane-3,8-diol is the chemically synthesized version of oil of lemon eucalyptus. It is applied to skin or to clothing to repel specific insects including mosquitoes, biting flies, and gnats. According to the Centers for Disease Control and Prevention, when repellents containing p-Mentane-3,8-diol were tested against mosquitoes found in the U.S., the p-Mentane-3,8-diol products provided protection similar to repellants with low concentrations of DEET.
  • Methyl nonyl ketone was originally registered in 1966 as a dog and cat repellent/training aid and an iris borer deterrent. Methyl nonyl ketone is currently found in only one insect repellent in the form of both a lotion and a spray.
  • IR3535 (chemical name, 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester), also called Merck 3535, is used as an insect repellent against mosquitoes, deer ticks, and biting flies. This biopesticide was registered as an active ingredient in 1999. Before it was registered with EPA, IR3535 had been used as an insect repellent in Europe for 20 years with no significant harmful effects.
  • Oil of Citronella comes from dried, cultivated grasses, and has a distinctive odor that masks the CO2 or lactic acid on our bodies that mosquitoes and other pests find attractive. It has been used for over 50 years as an insect repellent.1

What are the advantages of using biopesticides?

  • Biopesticides are usually inherently less toxic than conventional pesticides.
  • Biopesticides generally affect only the target pest and closely related organisms, in contrast to broad spectrum, conventional pesticides that may affect organisms as different as birds, insects, and mammals.
  • Biopesticides often are effective in very small quantities and often decompose quickly, thereby resulting in lower exposures and largely avoiding the pollution problems caused by conventional pesticides.

But it is important to note that while these biopesticides are “better” for you they are typically less effective than their counterparts that contain DEET.

What is DEET?

DEET (N,N-diethyl-meta-toluamide) is arguably the most widely recommended active ingredient in insect repellents. Proven effective, DEET does not kill insects. Instead it prevents biting insects like mosquitoes and ticks from zeroing in on your skin.

Biting insects follow the scent of carbon dioxide gas to find a meal. Skin and breath naturally give off a carbon dioxide. By spreading a small amount of DEET on exposed skin and applying it to external clothing, insects cannot readily locate the source of the carbon dioxide.

Each year about 30 million Americans use products containing DEET. Its greatest benefit is in repelling disease-bearing insects, like deer ticks that can transmit Lyme disease, and mosquitoes that can transmit encephalitis and West Nile virus. It also benefits those exposed to insects that might be carrying malaria, dengue fever and other diseases.

Can pregnant women use it?

DEET is the most effective and best studied product on the market, and is very good at preventing mosquito bites and keeping ticks from attaching. In the majority of animal studies, even at levels toxic to the pregnant mother, no increase in birth defects was noted. (When any insect repellent is applied directly to the skin, about 5 to 10 percent of the pesticide will be absorbed into your bloodstream and can reach the baby. In most cases, this level results in a very low exposure for your baby.)

Limited human studies have also found no increase in birth defects. And when DEET was used as recommended, no other problems were noted with babies’ survival, growth, or development in the first year of life.

In order to minimize exposure, always use a product with the lowest concentration of DEET needed for your protection. Products containing higher levels of DEET last longer but don’t provide greater protection.

What do you think? Do you have any experience with biopesticides and their success? What about DEET? Have you or your unborn child had any mal-effects because of such products? I’d love to hear from you regarding this topic.
1 Environmental Protection Agency