What exactly is a repellent? Is it something we should be putting on our skin? How does it work? These are all good questions that we should know the answer to. In this brief page we will discuss all of these questions.
A repellent is a chemical substance that when applied to the skin, clothing or other surfaces discourages arthropods (mosquitoes, biting flies, ticks, etc.) from landing on or biting that surface. Repellents work by interfering with the host-seeking receptors built into the pest organism. The more volatile the chemical repellent is the better it tends to work. Repellents simply mask or confuse the attractive signals that humans emit so that mosquitoes are unable to locate us. Mosquitoes have specific sensory receptors that provide them with the information they need to detect a source, orient to it, and travel to it to sample a blood meal.
Should we be applying repellent to our skin? To investigate this question let's look at some commonly available repellents individually. We'll separate repellents in two 2 categories, Synthetic and Natural/Plant-based.
Before synthetic repellents were developed in 1929, people routinely used natural compounds to protect against insect bites. During World War II, however, the United States government began testing more than 20,000 mosquito repellents to protect troops traveling to tropical areas. As a result, a highly effective synthetic repellent (N,N-diethyl-m-toluamide or DEET) was developed in 1953 and arrived on the market in 1956. In the late 1980s, a worldwide survey was conducted by the U.S. military to identify repellents not produced in the U.S. Of the 65 formulations not produced in the U.S., 33 contained DEET and the remainder contained natural oils or undisclosed ingredients. Currently, there are only five active ingredients registered for topical use in the U.S.