Repellents for use directly on skin
The Centers for Disease Control and Prevention (CDC) recommends the use of insect repellents that include active ingredients which have been registered by the U.S. Environmental Protection Agency (EPA). The following active ingredients have been reviewed and approved by the EPA for effectiveness and human safety if applied according to the instructions on the product label.
- DEET (Chemical Name: N,N-diethyl-meta-toluamide or N,N-diethyl-3-methyl-benzamide)
- Picaridin or KBR 3023 (Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester)
- Oil of Lemon Eucalyptus or PMD, the synthesized version of lemon eucalyptus (Chemical Name: para-Menthane-3,8-dial)
- IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl}-aminopropionic acid, ethyl ester)
The EPA characterizes DEET and picaridin as “conventional repellents” and Oil of Lemon Eucalyptus, PMD and IR3535 as “biopesticide” repellents, which are derived from natural materials.
Female mosquitoes bite because they need the protein found in blood to develop their eggs. Mosquitoes are attracted to people by skin odors and carbon dioxide from breath. Insect repellents do not kill the mosquitoes but repel or keep away insects. Repellents are effective only at short distances from the treated surface, so you may still see mosquitoes nearby.
Always read the label carefully for any warnings as well as to determine the active ingredient and its concentration. The effectiveness and duration of protection of different products varies and is affected by temperature, amount of perspiration, water exposure, and other factors. Products with higher concentrations of the active ingredient usually provide protection for longer periods of time, although there is no increased benefit of using products with 50% or higher concentration. Products with less than 10% concentration may offer only limited protection, generally for 1-2 hours. Some products have sustained or controlled release (micro-encapsulated) formulations, which may provide longer protection times, even at lower concentrations. Follow label directions and reapply repellent if you start to get mosquito bites. See below for additional guidance.
Selecting the appropriate insect repellent for children:
- 1 - 2 hours
< 10% DEET
< 10% picaridin
- 2 - 4 hours:
~30% oil of lemon eucalyptus
- 5 - 8 hours
Adapted from the Centers for Disease Control and Prevention's "How do I choose an Insect Repellent?"