Insect repellent Which type of mosquito repellent is most effective? There are many different kinds of mosquito repellents in the market. DEET containing products are generally most effective. Citronella, Soybean oil and 3-[N-Butyl-N-acetyl]-aminopropionic acid containing products also have mosquito repellent effects. Portable ultrasonic devices are less reliable when compared with DEET. Is DEET safe? DEET has been used for over 40 years, very few confirmed incidents of toxic reactions have been reported when the products were used according to product instructions. Rarely, DEET may cause skin rashes, blisters and irritation of the mucous membrane. Which concentration of DEET containing repellents should be used? The concentration of ‘DEET' should not exceed 35% for adult and 20% for children above 2 months of age. Apply the repellent according to product instruction and only to exposed skin areas. DEET is not recommended for use on infants less than 2 months of age, they should use mosquito net for health protection (e.g. infant carrier draped with elastic edge mosquito net). How often you should re-apply DEET repellents? Read and follow the instructions on the product label and use only enough amounts to cover exposed body area. You may only need to re-apply after heavy sweating or getting wet. Is DEET safe for pregnant or nursing woman? There are no reported adverse events following use of DEET containing repellents in pregnant or breast feeding women.