DEET-based products provided complete
protection for the longest duration. Higher concentrations
of DEET provided longer-lasting protection. A
formulation containing 23.8 percent DEET had a mean
complete-protection time of 301.5 minutes. A soybeanoil–based
repellent protected against mosquito bites
for an average of 94.6 minutes. The IR3535-based repellent
protected for an average of 22.9 minutes. All
other botanical repellents we tested provided protection
for a mean duration of less than 20 minutes. Repellent-impregnated
wristbands offered no protection.