CBART: When Skin Is in the Game

Courtesy Photo | CBART test fixture and its 10 identical test cells. (Image courtesy of Dr. Bruce D. McVeety, Battelle)  

FORT BELVOIR, VIRGINIA, UNITED STATES

11.01.2019

Courtesy Story

Defense Threat Reduction Agency's Chemical and Biological Technologies Department

Skin is the largest organ in the body and often the first to absorb environmental toxins. In the setting of a military conflict, exposure to toxins in the form of chemical warfare agents (CWAs) could not only injure skin but also cause paralysis or other neurological harm or death. Protective gear can safeguard the warfighter from exposure to CWAs; however, current garments are bulky, poorly ventilated, and hot to wear.

Since skin protection and unhampered movements are critical to warfighter safety, the Defense Threat Reduction Agency’s Chemical and Biological Technologies Department (DTRA CB), and the Joint Program Executive Office for Chemical and Biological Defense, are improving protective garments that are part of the Uniform Integrated Protective Ensemble Family of Systems.

Future protective garments will be lighter and less bulky, and they will also reduce the heat-related burden that warfighters experience from wearing such gear. Before this next generation of protection is ready for use, it must undergo rigorous testing. Therein lies another challenge: the testing method itself needs to improve. To address this need, DTRA CB funded the development of the Chemical/Biological Agent Resistance Test (CBART). Because it produces accurate and reproducible data, CBART offers researchers a promising new technology to evaluate the effectiveness of future protective materials in safeguarding the skin from CWAs.

CBART was designed with hardware and software to address current testing limitations in evaluating how well a swatch of protective material safeguards the skin from CWAs. Currently, permeability evaluations are time-consuming, do not pinpoint the exact moment when a CWA penetrates the material, are costly, do not generate data that can be reproduced from one type of material to another, and do not properly simulate natural wind flows experienced on the battlefield. Also, materials with different air porosities, such as the three listed below, require their own unique testing conditions to accurately evaluate how well they keep CWAs from reaching the skin:

• Carbon-based protective materials, such as TEX-SHIELD, are air-permeable.
• GORE-TEX, a selectively permeable membrane, is air-impermeable.
• Butyl rubber, used in boots and gloves, is impermeable.

CBART offers researchers many benefits. It is material-agnostic, which means that it enables the use of the same testing conditions for materials regardless of their differing porosities, thereby allowing for data comparability. Through its precisely controlled airflows, CBART measures the amount of CWA that penetrates a swatch of material. CBART has 10 identical, self-contained areas (or cells) to perform tests. In each cell, researchers can expose a swatch of material to a CWA in a liquid or gas state. CBART then analyzes the identity and quantity of the CWA in the air that permeates each material. The lower the CWA breakthrough, the more effective the material as a barrier.

CBART yields data on the material’s permeability every three minutes, allowing researchers to note the time a CWA penetrates the swatch of material — i.e., when the barrier fails — and compare how different materials perform in preventing CWAs from reaching the skin. Additionally, CBART’s multiple cells allow researchers to simultaneously reproduce a test, which in turn increases confidence in the data collected and reduces the required number (and cost) of tests needed to evaluate a material. Lastly, the new equipment generates environmentally relevant airflow conditions by precisely controlling temperature, humidity, wind speed, and atmospheric pressure — allowing the testing conditions to match those expected on the battlefield.

CBART also enables researchers to evaluate novel materials, such as those that impede CWAs from reaching the skin and also destroy them. To do this, researchers analyze the air leaving the cell to assess if the product used to destroy the agent, does not, in turn, harm the warfighter.

CBART successfully completed its final validation testing confirming that it performs as designed. DTRA CB’s work with Battelle Memorial Institute and Creare LLC in developing CBART resulted in a better test environment that gives researchers stronger data that will ultimately provide better protective garments for warfighters.

• Date Taken: 11.01.2019
• Date Posted: 11.01.2019 17:36
• Story ID: 350218
• Location: FORT BELVOIR, VIRGINIA, US