Not all bug sprays are created equal, and rightfully so.

Many insect repellents, unless otherwise labeled, are formulated for adult usage. Unfortunately, what is right for adults may be a toxic dose for a toddler or infant.

Maury Contreras, a nurse practitioner in Pediatric Dermatology at Children's Medical Center Dallas advises parents to choose an age-appropriate insect repellent, one that is made for children, and to follow application directions found on the label. By law, all bug repellent products must state any age restriction on the product’s label. (See below for age-specific guidelines on how to use repellents based on your child’s age.)

To DEET, or not to DEET
That is the question. The most powerful, effective insect repellents contain a chemical called DEET. Repellents used on children should have only a small concentration of DEET and not all products contain the same concentration, or amount. The amount of DEET that a product contains is measured in a percentage, such as 10 percent DEET. The amount of protection depends on how much DEET the product contains:

• 30 percent DEET provides approx six hours of protection
• 15 percent DEET provides approx five hours of protection
• 10 percent DEET provides approx three hours of protection
• 5 percent DEET provides approx two hours of protection

The American Academy of Pediatrics recently stated that products with a concentration of 10 percent DEET appear to be as safe as products with a concentration of 30 percent when used according to the directions on the label. AAP also recommends that repellents with DEET should not be used on infants younger than 2 months.

DEET Alternatives
The Centers for Disease Control and Prevention has listed alternative ingredients to DEET. Although the products below are considered safe when used appropriately, long-term follow-up studies are not currently available. Care should also be taken with herbal products, since large doses of some herbs can be dangerous and little research has been conducted on their safety.

• Picaridin, also known as KBR 3023, is currently available in 5 percent to 10 percent solutions.
• Oil of lemon eucalyptus is comparable in its duration of effectiveness to lower concentrations of DEET. According to the label, oil of lemon eucalyptus products should NOT be used on CHILDREN YOUNGER THAN 3 YEARS.
• Soybean oil – 2 percent soybean oil has similar levels of effectiveness to DEET.

Safety guidelines for applying insect repellent on children

• Check label for specific instructions – always read the entire label and follow the recommendations. Application directions vary by product. 
• Apply repellents only to exposed skin and/or on top of clothing and heavy application and saturation generally are unnecessary for effectiveness. Do not apply repellent under clothing.
• When using repellent directly on a child’s skin, apply it to your own hands and then rub it on your child. Avoid children's eyes and mouth and use sparingly around ears.
• Do not apply repellent to children's hands – children may tend to put their hands in their mouths.
• Do not apply on irritated skin, cuts, wounds or sunburned skin.
• Do not get it in eyes. If you do get insect repellent in your child’s eyes, rinse with water right away.
• If you are spraying, be careful that your child does not breathe it in – always spray products in a well-ventilated place. Don’t spray in an enclosed area, tent or near food.
• Do not allow young children to apply insect repellent on themselves, always have an adult apply it for them.
• Repellents are poisonous if swallowed, so keep repellents out of reach of children.
• When your child does not need the protection anymore, wash the skin with soap and water or bathe. This is important when repellents are used repeatedly within a day or on consecutive days. If repellent has been applied to clothing, wash treated clothing before wearing again.
• Using DEET and sunscreen products at the same time is an acceptable practice but apply it just once. The use of combination products is not recommended because sunscreen needs to be reapplied after swimming and mosquito repellent does not. Reapplying DEET-based products frequently can lead to overexposure and possible side effects. If you're using a sunscreen that also contains DEET and you need to apply more sunscreen, use one that's DEET-free.
• Although there is no known hazard to breastfed infants, nursing mothers may wish to consider DEET alternatives, such as using protective clothing and avoiding exposure to insects (see above). 

Allergic reactions to insect repellent

• If your child has sensitive skin, or has multiple allergies, it might be best to apply a small amount of repellent to one area for several hours and observe before applying to the rest of the body.
• If a child develops a rash or other apparent allergic reaction from an insect repellent, stop using the repellent, wash it off with mild soap and water and call your local poison control center for further instruction.
• If you see a severe reaction to the product, wash the skin and get medical help right away. Take the repellent product with you to show the doctor.

Guidelines for age-specific use of repellents

  Children younger than 2 months:

• Do not use insect repellents with DEET on infants.
• Dress your baby in light-colored clothing that covers as much of his skin as possible. According to CDC, light colors allow you to see ticks on your baby’s clothing and can act as a deterrent -- dark colors are more appealing to biting bugs.
• Mosquito netting can be used over infant carriers.
• Products containing citronella or lavender oil should not be used on infants.

  Children younger than 6 months:

• Use a product that contains no more than 10 percent DEET or less. Use only once a day and apply sparingly. Once indoors, use soap and water to rinse off the areas of your baby's skin where you applied the repellent. Do not use repellent repeatedly over a long period of time.
• Do not put any repellent product on your baby's hands because young babies suck on them.
• Don't use DEET products near an infant’s food; infant digestive systems are highly sensitive to absorption of potential toxins.
• If you're using a sunscreen that also contains DEET, apply it just once. If you need to apply more sunscreen, use one that's DEET-free.
• If you'd rather not use products containing DEET, bug repellents made with citronella are considered safe for babies 2 months and older, but since they're not as effective as DEET they need to be reapplied throughout the day.
• See general guidelines for safe application above.

  Children ages 6 months to 2 years old:

• If there is a high risk of complications from insect bites (you live in an area where there are reports of West Nile virus) use products with DEET only once a day and use a product that contains no more than 10 percent DEET or less.
• Use product sparingly – do not apply to child’s face or hands.
• Do not use repellents repeatedly over a long period of time.
• See general guidelines for safe application above.

  Children between 2 and 12 years old:

• Use a product with no more than 10 percent DEET.
• Do not apply more than three times a day.
• Use product sparingly. Do not apply to child’s face or hands.
• Do not use repellents repeatedly over a long period of time.
• See general guidelines for safe application above.

  Children older than 12 years:

• Use a product with 30 percent DEET or less. 
• See general guidelines for safe application above.

Resources
US Environmental Protection Agency
Centers for Disease Control (CDC)
American Academy of Pediatrics (AAP)
Insects in the City™ – Texas Cooperative Extension