As we enter the summer season it’s time to consider how to best protect outdoor workers.  One of the most important defenses in our arsenal against insects and vector diseases is insect repellents. 

Many people have questions regarding the differences between the two most common insect repellents recommended by most resources. These two chemicals are Permethrin and DEET.  This additional information will help clarify any questions.

One of the most important differences between DEET and Permethrin is the method of application. For example, Permethrin is applied directly to clothing, while DEET can be applied to the skin and clothing.  It is important to remember that DEET is an insect repellant, while Permethrin is an actual insecticide. They work differently and so must be applied differently.

DEET: (chemical name N,N-diethyl-meta-toluamide) is used as the active ingredient in many insect repellents. Insect repellents that contain DEET offer some of the best protection against mosquito bites, but must be frequently applied.

DEET is designed for direct application to skin and repels insects rather than killing them. Higher concentrations of DEET may have a longer repellent effect; however, concentrations over 50% provide no real added protection.

When using DEET containing products, follow these recommendations:

• To apply to face, first spray product onto hands, then rub onto face.
• Use only when outdoors and wash skin with soap and water after coming indoors.
• Use just enough repellent to cover exposed skin and/or clothing. Avoid over-application of the product.
• Do not breathe in, swallow, or get into the eyes (DEET is toxic if swallowed.) Do not put DEET repellent on wounds or broken skin.

Permethrin:  an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower. Permethrin isn't a repellant, but a powerful insecticide that kills insects on contact.

Permethrin is generally considered safe for human use and most mammals, with one exception. Cats lack an enzyme used to detoxify Permethrin, so it can be toxic to cats.

When using Permethrin, follow these recommendations:

• Don't apply this product to skin.
• Spray permethrin onto clothing, where it bonds tightly to most fabrics and lasts through multiple washings. It's non-staining and has no odor after it dries.
• Do not breathe in, swallow, or get permethrin into the eyes.

DEET and Permethrin are important tools to help protect workers from bites, stings, and vector borne diseases. Your employees must understand the correct use of these two important chemicals. The number and types of diseases one can contract from ticks and mosquitoes, for example, are pretty grim. Yet, through judicious use of these chemicals and proper protective clothing such a long sleeved shirts and long pants one can greatly reduce risks of exposure to these biological hazards.

For additional information on insect repellent use check out this FAQ page from the Centers for Disease Control. 

Posted ByTony Jones, RN, COHN, OHST, WCP®