Advancement in the Man-In-Simulant-Test Methodology and Development of Next Generation Manikin for Chemical and Biological Protection Research

The Man-In-Simulant-Test (MIST) has been the primary method used to evaluate full ensembles with regards to their chemical protective performance since it was developed by the U.S. Army during the early 1990s. MIST evaluations involve exposing human test subjects wearing full protective ensembles to a low toxicity simulant for chemical warfare agents. The target property that is assessed by the MIST is the ensemble's ability to prohibit or minimize inward leakage of the simulant through the closures and interfaces such as seams, seals, or zippers.;The first area that was addressed by this research was the advancement of the current MIST methodology. A detailed extraction and analysis method was developed to remove the simulant, methyl salicylate (MeS), from the Passive Adsorbent Dosimeters (PADs) that are used to measure the leakage inside the ensemble. The removal of MeS from the adsorbent was shown to have an extraction efficiency greater than 98% across the entire expected range of MeS amounts. The liquid chromatography method was shown to be capable of detecting MeS in the expected ranges, provided an overall limit of quantitation of 30 ng/PAD, and only required 4.5 minutes to analyze a single sample.;A bench-scale MIST chamber was developed to quickly expose multiple PADs or materials at various MeS concentrations. The chamber was shown to be capable of maintaining a desired concentration for an extended period of time and could also be repeatedly filled to the same conditions across multiple days.;An extensive investigation was conducted to characterize the PADs based on the consistency of their physical properties and the effect of varying the exposure conditions on the measured uptake rate. Within a single lot, the PADs were shown to be relatively consistent in surface area and responded linearly to a range of exposure dosages. A significant variability between PAD lots was observed and should be further investigated. The PAD handling procedures were also investigated, and it is recommended to either extract the PADs within an hour of being exposed or store them at extremely cold temperatures to prohibit any mass transfer from occurring during storage.;Various fabrics were investigated to determine their MeS uptake rates in both the bench-scale and full-scale MIST chambers. Fabrics comprised of 100% polyester or cotton were shown to adsorb very little MeS, but incorporating only 5% spandex greatly increased both the capacity and uptake rate of the fabrics. A 95/5 polyester/spandex jersey fabric was found to have a thirty minute uptake rate very similar to the values reported for human skin, and therefore could potentially serve as a skin simulant in MIST protocols utilizing manikins.;The second main area that was addressed by this research was the development of a next generation manikin for use in MIST evaluations. An articulated thermal manikin was attached to an elliptical walker to increase the range of motion. A baseline for the observed variability in MIST results with human subjects was determined by conducting three separate trials with eight human subjects in the MIST Facility at NC State University. These results were compared to three manikin evaluations in the same NFPA 1994 Class 3 Ensemble. It was found that manikins and human subjects can produce consistent MIST results. It was also confirmed that three manikin evaluations produce the just as much variability as three human subjects, and therefore should not be used to replace a standard eight human subject test.