U.S. Army Soldier Systems Center-Natick
Public Affairs Office
Natick, MA 01760-5012
Contact: Chief, Public Affairs Office
Date: March 21, 2001
NATICK, Mass. -- Smacking, scratching and twitchiness spurred by attacking bugs may be reduced dramatically with permethrin-treated Battle Dress Uniforms.
More than 350 soldiers from 1st Battalion, 509th Infantry, at Fort Polk, La., completed an eight-month evaluation of permethrin factory-treated BDUs in March 2000 and the uniforms are now waiting for approval by the Army Uniform Board to become a clothing item troops can purchase.
"When people are completely covered with insect bites, they're miserable and less effective as soldiers," said Kathy Swift, textile technologist at Product Manager-Soldier Equipment.
More importantly, insects are dangerous. It was 15 years ago when the Army started investigating the possibility of applying insect repellent to textiles-BDUs in particular-to ward off diseases, said Bart McNally, senior research chemist at the U.S. Army Soldier Systems Center (Natick), who patented the process of machine-treatment of BDUs with permethrin.
Permethrin is a popular and safe chemical that repels and kills insects. The Environmental Protection Agency and Surgeon General have approved it for years for use on textiles. In the early 1980s, the Army approved a permethrin spray can that soldiers could use to treat their uniforms. Still, it was effective only for a short time.
Researchers initially developed two application methods. In 1989, the Individual Dynamic Absorption kit was unveiled that's still available today. The kit contains two bags, disposable plastic gloves and permethrin solution. It requires soldiers to combine water, the chemical and uniform in a bag, then shake it, wait for it to absorb, and let it dry.
"It was very effective but wasn't well-liked," McNally said. "This was not ideal because it was up to the individual and exposed the soldier to concentrated permethrin."
The second method was the pad roll, an industrial method of applying permethrin. McNally said it was rejected because of concern over chemical exposure to textile employees handling the treated fabric.
McNally discovered that a garment machine, similar to a washing machine, used to apply water repellent and fire retardant coupled with a metered addition process could also apply insect repellent. Treatment coverage was as thorough as with the kit. Uniforms could finally be treated in bulk and without human exposure to the raw chemical.
With the uniforms ready to go, testing had to be completed to ensure their effectiveness.
Three sets of hot weather permethrin BDUs were issued to the soldiers, allowing the troops to wear a treated uniform throughout the study.
They reported wearing each uniform an average total of 55 days for an average 20 hours per day.
The permethrin BDUs proved to be cost-effective (about $6-$8 more per set), lasting for the life of the uniform through 50 washings and gave soldiers protection without handling the chemical.
The study revealed that nearly 90 percent of the participants believed they received fewer bites than usual wearing the treated uniform, the treated uniform was safe to wear, and that they were receiving fewer bites even at the end of the evaluation.
Permethrin had no significant impact on basic uniform performance. Soldiers believed that wearing the treated uniform led to fewer insect bites, controlled insects on and around them, and offered better protection than an untreated uniform with insect repellent. Eighty-seven percent of the evaluation participants preferred the permethrin uniform to current options, which for this group consisted mainly of insect repellent.
"It's pretty impressive that the soldiers aren't even getting one chigger. They even protected one soldier from fire ants," McNally said. "From day one our goal was to protect soldiers against vector-borne diseases. Now it's a reality."
A few people were sensitive to the uniform and developed a small rash, according to Swift, but complaints have been minimal. Swift said the treatment could be used in applications beyond the military, such as with clothing for outdoorsmen. McNally said he's working on using a similar application for Nomex used in tanker coveralls and flight suits.
Natick is part of the U.S. Army Soldier and Biological Chemical Command (SBCCOM). For more information about SBCCOM or the Soldier Systems Center (Natick), please visit our website at http://www.sbccom.army.mil.