ARS | Publication request: Effect of fabric construction on the protection from mosquito bites by Permethrin-treated U. S. military uniforms.

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2009
Publication Date: N/A

Technical Abstract: The United States Military is transitioning from field treatment of uniforms with permethrin to factory-treatment as a solution to produce a uniform that provides high levels of protection from insect bites, without retreatment, throughout the lifetime of the uniform. In 2007, the United States Marine Corps (USMC) was the first service to transition to factory-treatment only. One of the initial concerns regarding the retention of permethrin on USMC Marine Corps Combat Utility Uniforms (MCCUUs) was that the permanent press finish significantly affected the retention of the permethrin. While this may have been a factor in permethrin absorption and retention, the factory-treated MCCUUs treated at 0.140-0.170 mg/cm2 initially still retained approximately 0.040 mg/cm2 permethrin after 50 launderings, the expected uniform lifetime. In addition to chemical examination of permethrin retention, the biological efficacy of the uniforms is determined. This is accomplished using a laboratory assay that compares the mosquitoes that bite though a treated uniform and is corrected against an untreated control in a 15 minute trial. Using this assay, it was determined that after 50 launderings, the MCCUU still prevented > 95% of mosquitoes from biting volunteers in laboratory bioassays. In 2008, the U.S. Army Combat Uniform (ACU) was examined after treatment by Individual Dynamic Absorption (IDA) kits. This uniform performed as well as the MCCUU with respect to biological efficacy, yet retained only 0.008 mg/cm2 permethrin after 50 launderings. More recent uniforms contain fire-resistant materials in the uniform, e.g. the Fire-Resistant Army Combat Uniform (FRACU). These uniforms retain permethrin less efficiently and were determined to provide lower levels of bite protection from mosquito bites. It was also noted that these FR uniforms were also more permeable to provide comfort to the wearer. When the air permeability of the uniforms studies were compared to the bite protection levels, a strong correlation between air permeability and bite protection was observed. This talk will focus on the relation between air permeability of uniforms and the overall bite protection afforded by the fabric.