Change in permeation parameters and the decontamination efficacy of three chemical protective gloves after repeated exposures to solvents and thermal decontaminations.

BACKGROUND: Chemical protective clothing (CPC) and gloves, which provide adequate protection, are usually too expensive to be considered disposable. Repeated use of CPC without effective decontamination may result in secondary exposure and injury. However, decontamination may change the physical and/or chemical properties of the barrier material, causing variations in breakthrough time (BT) and steady-state permeation rate (SSPR).
METHODS: Glove materials including neoprene, Guardian butyl rubber, and nitrile synthetic rubber were selected for this study. Toluene and acetone were chosen as the challenge chemicals. Permeation was measured in a closed loop system using a 2.5 cm permeation cell and a MIRAN infrared analyzer (Foxboro, MA). Following the permeation test, the samples were thermally decontaminated. After each exposure/decontamination cycle, BT and SSPR were measured. A total of 260 permeation tests were conducted. Permeation test results were collected on each material/chemical combination for up to 10 exposure/decontamination cycles.
RESULTS: On average, changes in BT and SSPR in comparison with respect to new swatches were 11.5% and 13.7% after seven exposure/decontamination cycles. The percentages increased to 26.6% and 15.9% after 10 exposure/decontamination cycles, respectively. For at least seven cycles, the BT mean for four out of five material/chemical combinations tested (neoprene/acetone, neoprene/toluene, nitrile/acetone, and nitrile/toluene) was not significantly different from the original value of the BT for each corresponding swatch. Similarly, the SSPR mean for each of the five material/chemical combinations after at least five cycles was not significantly different from those for new swatches. The BT mean for the butyl/toluene combination, however, was significantly different from the new swatches even after the first exposure/decontamination. The SSPR mean was significantly different after five cycles compared to the new swatches.
CONCLUSIONS: Except for the butyl/toluene combination, thermal decontamination was an effective method in removing the solvents from the matrix of selected glove materials. Multiple reuses of some chemical protective gloves could be safe if effective decontamination methods are used and the glove materials do not have significant degradation.