Bio Monitoring

Insect Shield Repellent Apparel Study
Summary of Evaluation of Potential Exposures and Health Risks Associated with Insect Shield Repellent Apparel
(BOIS Bio-Monitoring Study)
Sponsor: Insect Shield, LLC, Greensboro, NC                                                                                  
Performing Laboratory: Info Scientific Inc., Manassass, VA

In 2005, Insect Shield commissioned one of the most detailed studies ever conducted on the subject of dermal exposure to wearers of permethrin-treated clothing. The clothing tested was treated using the Insect Shield proprietary treatment process and the Insect Shield proprietary permethrin formula. Therefore, the resulting conclusions only apply to wearers of Insect Shield clothing, and are not representative of other permethrin treatment processes and formulas.   

Three analytical methods were used to determine transfer of permethrin from clothing onto the skin of the wearer: gauze wipe, whole body dosimeter, and hand wash. In addition, a urinary bio-monitoring study was performed to ascertain the level of permethrin absorbed into the body of the test subjects. This bio-monitoring evaluation is the “gold-standard” of assessment and created direct measures of exposure specific to the use of Insect Shield apparel. The data obtained from the four test methodologies are very well behaved. Each data set correlates with and corroborates the other data sets, strengthening the validity and soundness of the overall study.
  • Sixteen individuals between the ages of 39 and 66 were studied to conduct the analysis. Of the sixteen, 7 were females and 9 were males. 
  • The evaluation took place between the months of May and August, and was conducted in 3 locations: Saskatchewan, Canada, Creedmoor, North Carolina, and Durham, North Carolina.
  • All of the subjects wore complete sets of Insect Shield apparel for 7 to 10.5 hours per day. They participated in non-choreographed activities, mainly in the outdoors, which offered a high level of activity.
  • The clothing consisted of long-sleeve shirts and long pants made from various blends and weights of fabric. 
  • All diets were managed and monitored throughout the evaluation to prevent any of the results from being skewed.
  • The results were then extrapolated to determine the impact of long-term, prolonged use.
The study concluded that all measured levels of exposure were well below the U.S. Environmental Protection Agency’s (EPA) level of concern. The EPA concern level is considered to be a very conservative standard.
The study results also showed that garments treated using the proprietary Insect Shield formula and process yield permethrin exposure levels 182 times lower than exposure levels measured on garments treated with permethrin via a standard spray method. It is important to note that exposure levels associated with the standard spray method are well within the EPA’s acceptable limits. Furthermore, the standard spray method has been utilized since the late 1970s with an excellent safety record. 

In summary, these impressive results confirm that Insect Shield binds permethrin so tightly to fabric fibers that it remains in place—and does not transfer onto the skin or into the environment.