A survey of available insect repellent products reveals a range of repelling efficacies as well as potential health risks. How can these benefits and risks be understood, and what are the implications for formulations?
Insect repellent products offer skin protection against vector transmitted diseases. The application of these products to our skin requires that the physiology of skin and our internal body have very good tolerance for the penetrating portion of the repellent. Multiple insect repellents currently available, both natural and synthetic, are meant to address the repellency issue while giving a somewhat lesser importance to the skin tolerance and general safety in the human body. This safety aspect is even more critical in combined products where other ingredients can influence dermal penetration properties.
This article discusses the main commercial insect repellent active chemicals and their efficacies in light of their tolerance by our skin and body. Implications for finished product formulation are also discussed.