Integrated Logistics Support Services: SIN 871-5
RTI is a recognized leader in aerosol challenge tests of protective garments, having developed the systems and swatch test methodologies now specified by the Department of Defense for aerosol challenge tests. Since 1985, RTI has provided ergonomic/human performance analysis, testing, and method development for the U.S. and Canadian military and for first responders such as fire departments. Over 430 full-scale human subject tests, over 200 manikin tests, and over 150 swatch tests have been performed.
Recently, RTI performed an ergonomic/human performance analysis of the level of aerosol protection afforded by chemical protective garments and equipment worn by the U.S. military. System-level, human-use, aerosol challenge tests were performed in RTI's full-scale aerosol exposure chamber/wind tunnel. The wind tunnel room contains a 3.1-m diameter, 40-hp vane-axial fan centrally located in a 9.3- X 15-m sealed room. Wind speeds up to 30 mph may be achieved within the 2-m diameter test section. The facility provided controlled temperature, humidity, wind speed, and aerosol conditions.
During this analysis, military personnel or other test subjects wore the equipment and performed a standard series of exercises. The challenge aerosol was a safe, fluorescently tagged, and aerosolized powder. The fluorescent tracer in the aerosol allowed the amount of aerosol deposited on skin to be directly measured after each test was performed. RTI also has a swatch test apparatus for the aerosol challenge of fabric samples that operates at controlled temperature and humidity conditions (typically, 90°F and 60% RH), constant 0.1-inch H2O pressure drop, and constant face-velocity modes. Microbiological aerosol test facilities at RTI can be used for the generation and measurement of biological aerosols, if required for testing.
The chemical engineering expertise that RTI used in this work included preparation, handling, and measurement of chemical and biological aerosol challenges and evaluation of results. In addition, the means of tagging the solid-phase silica powder with the fluorescent tracer was developed by RTI under prior contract with the U.S. Navy. When testing requires, we can also test with liquid-phase challenge aerosols.