Bug spray offers protection from insect bites and helps reduce the transmission of insect-borne diseases. The compounds within bug spray work by deterring insects or directly affecting their physiology.
How Repellents Work
Bug repellents create a sensory barrier that discourages insects from landing on or biting treated skin or clothing, without killing them. Common active ingredients like N,N-Diethyl-meta-toluamide (DEET), picaridin, and oil of lemon eucalyptus (OLE) achieve this effect. DEET interferes with the ability of mosquitoes to detect human odors, such as carbon dioxide and lactic acid. It can block the olfactory receptors on an insect’s antennae, making the treated person less detectable.
Picaridin confuses insect olfactory systems, making it difficult for them to locate a blood meal. It creates a vapor barrier that masks human scents, similar to DEET. Oil of lemon eucalyptus contains p-menthane-3,8-diol (PMD) as its active compound. PMD disrupts an insect’s sense of smell. These repellent compounds do not harm the insects but disorient them, prompting them to fly away.
How Insecticides Work
In contrast to repellents, insecticides in bug sprays are designed to kill insects upon contact or ingestion. Pyrethroids, a class of synthetic compounds chemically similar to natural pyrethrins found in chrysanthemum flowers, are common active ingredients in these types of sprays. Examples include permethrin and cypermethrin, which act as neurotoxins targeting the insect nervous system. These chemicals interfere with the functioning of an insect’s nerve cells.
Pyrethroids work by disrupting the voltage-gated sodium channels in insect neurons, which are responsible for transmitting nerve impulses. They bind to these channels, preventing them from closing after an impulse is transmitted. This leads to prolonged opening of the channels, causing continuous firing of nerve signals. The uncontrolled nerve activity results in hyperexcitation, tremors, and ultimately paralysis, followed by the insect’s death. This direct toxic action distinguishes insecticides from repellents, which merely deter insects without causing mortality.
Using Bug Spray Safely
Using bug spray safely involves attention to product labels and application methods. Always read and follow the instructions provided by the manufacturer, as formulations and concentrations vary. When applying, spray bug repellent directly onto exposed skin or clothing, ensuring even coverage without oversaturating.
Avoid spraying directly onto the face; instead, spray a small amount onto your hands and then apply it carefully to the face, avoiding eyes and mouth. Do not apply bug spray under clothing, and wash your hands with soap and water after application. For children, an adult should apply the product, and it should not be used on their hands or near their eyes and mouth. Pregnant or nursing individuals should consult their healthcare provider before using bug spray products.