Choose a repellent with no more than 10% to 30% concentration of DEET (look for N,N-diethyl-m-toluamide on the label). Use lower concentrations if kids will be outside only for an hour or two. If they’re outside longer, consider using a repellent with a higher concentration of DEET. (The higher concentration means that it will last longer.)
Generally, repellent with DEET should not be applied more than once a day, and is not recommended for babies younger than 2 months old.
DEET can be used on exposed skin, as well as clothing, socks, and shoes, but should not be used on the face, under clothing, on cuts or irritated skin, or on the hands of young children.
Do not use a single product containing both sunscreen and DEET
Sunscreen needs to be reapplied frequently, while DEET should not be applied more than once a day.
Concentrations higher than 30% are not more effective and the chemical (which is absorbed through the skin) can be toxic.
Be sure to follow the directions on the label.
If you apply insect repellent to exposed skin, do so sparingly.