Here's how long common active ingredients will last: The majority of popular bug-spray brands, such as Off, contain N,N-diethyltoluamide, more commonly referred to as DEET, as their active ingredient.

We only tested bug sprays with active ingredients approved by both the Centers for Disease Control and Prevention (CDC) and Environmental Protection Agency (EPA): DEET, picaridin, oil of lemon ...

James says four active ingredients are scientifically proven to work on mosquitoes. Three of them: DEET, IR3535 and Picaridin (also known as Icaridin) are human-made, but the fourth, PMD ...