This article discusses the harmful effects from breathing in or swallowing bug spray.

This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at 1-800-222-1222.

The majority of bug repellents contain DEET (N,N-diethyl-m-toluamide) as their active ingredient. It is one of the few insect repellants that work. DEET is recommended to prevent mosquito-born diseases such as malaria, dengue fever, and West Nile virus.

Other less effective forms of bug sprays contain pyrethrins. Pyrethrins are a pesticide created from the chrysanthemum flower. It is generally considered non-toxic, but it can cause breathing problems if large doses are inhaled.

Bug sprays, or insect repellants, are sold under various brand names.

For pyrethrins:

• Breathing difficulty
• Coughing
• Loss of alertness due to imbalance in oxygen level
• Tremors (if a large amount is swallowed)
• Seizures (if a large amount is swallowed)
• Upset stomach
• Vomiting

For DEET:

Persons applying DEET to their skin may get hives or have mild redness and irritation. These symptoms are usually mild and will go away when the product is removed from the skin.

Persons who use very high concentrations of DEET on their skin over a long period of time (such as military personnel or game wardens) may have more severe skin reactions that include blistering, burning, and permanent scars of the skin. Other symptoms associated with long-term use of high amounts of DEET (over 50% concentration) include insomnia and mood changes.

If DEET is unintentionally sprayed into the eyes, nose, or mouth, you may feel a temporary burning sensation and have redness. Washing the area will usually make the symptoms go away. Burns to the eye may require medication.

When small amounts of DEET are swallowed by mouth, symptoms may include:

• Moderate-to-severe stomach irritation
• Nausea
• Vomiting

Low blood pressure (hypotension) and low heart rates (bradycardia) may occur if a large amount is swallowed.

By far, the most serious and devastating complication of large DEET poisonings is neurological damage. Patients may have disorientation, clumsiness when walking, seizures, or coma. Death is possible in these cases.

DEET is especially dangerous for small children. Seizures may occur in small children that are consistently exposed to DEET on their skin for long periods of time. Care should be taken to only apply lower concentrations of DEET to children for short periods of time. Products containing DEET probably should not be used on infants.