Safety Discussion
Bob Harrison


DEET is an excellent mosquito repellent, but it is a fairly poor tick repellent.

There are pros and cons to each product, but as a tick repellent, permethrin wins hands down. Permethrin is an
insecticide derived from a chemical found in the chrysanthemum family of plants. It is a spray that is used on clothes only, and is deactivated and made less effective by the oils on our skin. Once it is sprayed on our clothing, it becomes odorless and can last for several weeks with a single application. Once it is applied, most ticks will curl up and fall off if they make contact, and will eventually die if there is prolonged exposure.

Pros and Cons:
DEET needs to be applied regularly and can only work as it is evaporating. Permethrin works for weeks after it has dried inside clothing fibers.  DEET is applied directly to the skin and can be absorbed through the skin. Permethrin is applied to
clothing only and has limited contact to the skin.  DEET has a detectable odor. Permethrin smells only until it dries.
DEET does not kill or disable ticks and is a poor repellent. Permethrin works instantly and is extremely effective. It is the tick repellent of choice by the military.  DEET can melt synthetic clothes like nylon. Permethrin causes no damage to any known cloth or synthetic fiber.  DEET products are easy to find. Permethrin is hard to find and more expensive.  DEET is an effective fish repellent.

Permethrin-containing products that are approved for human use are manufactured by Coulston labs, and can be found under labels such as Duranon, Permanone, and Congo Creek Tick Spray. A 0.5 % veterinary permethrin product can be found in most feed stores and horse supply shops as a horse tick repellent. The veterinary products tend to cost about half the price per ounce as the human-use product. 

The Minnesota Insect-Borne Disease Education Council conducted a field test in Jay Cook State Park in northern Minnesota, and found that the permethrin products outperformed the DEET-containing tick repellents. A shoe was sprayed with Duranon (0.5% permethrin). Three weeks later, it was tested against a recently sprayed shoe using Deep Woods Off (35 % DEET). Ticks that made contact with the Duranon-sprayed shoe immediately rolled up and dropped off. Ticks on the soaking-wet DEET saturated shoe continued to crawl unimpaired.

One last tip for you fishermen out there:
DEET is perhaps one of the most effective fish repellents known to man. Just a few parts per million can send game fish like salmon and trout to the other end of the fish tank. If you like to keep mosquito repellent in your tackle box, you may have unknowingly contaminated all of your fishing lures! Be sure to take care not to handle any fishing tackle once you have applied mosquito repellent. Just a few parts-per-million can repel more fish than mosquitoes!

To avoid ticks:
Wear light-colored clothing.
Tuck your pants into your boots.
Tuck your shirt into your pants.
Wear a hat.
Spray your shoes, socks, belt-line, collar and hat with a permethrin-containing tick repellent.
Do a tick check after walking in high-risk areas.
Put any clothes that might have live ticks on them into a hot dryer for ten minutes to kill all

Keep your Family Safe! Do Tick Checks!