The benefits of using insect repellent can definitely outweigh the risks when used properly. Bug spray can protect against insect bites and contractable diseases like West Nile and Lyme Disease in the US and Malaria and Dengue in the tropics.
What concerns some about insect repellents are the possible harmful effects of DEET, the active ingredient in most repellents. Used in excess or on infants under six months old, DEET may cause side effects. Although 30 percent of the US population will use DEET-containing repellents during the summer, there have been fewer than 50 life-threatening events (less than one in a million). Most adverse effects are skin rashes or reactions, so assess your skin’s response to DEET on a small area of your arm first and make sure to follow directions.
General guidelines call for applying to undamaged exposed skin, not on skin which will be covered by clothing, and washing between applications or after protection is no longer needed. DEET works moderately to repel ticks from exposed skin, but also consider a permethrin spray to cover clothing. It’s okay to use insect repellent as long as you remain informed about the pros and cons.