Comparison of fluorescence and rinsing methods for assessing dermal exposure

Efficacy of Different Hair and Skin Decontamination Strategies with Identification of Associated Hazards to First Responders

Background: Established procedures for mass casualty decontamination involve the deployment of equipment for showering with water (such as the ladder pipe system [LPS] and technical decontamination [TD]). This necessarily introduces a short, but critical delay. The incorporation of dry decontamination to the incident response process offers the potential to establish a more rapid and timely intervention. Objectives: To investigate the effectiveness of various dry (DD) and wet decontamination strategies for removing a chemical warfare simulant (methyl salicylate; MS) from the hair and skin of human volunteers. Methods: The simulant was applied to volunteers via whole body exposure to an aerosol. Three decontamination protocols (dry, LPS and technical decontamination) were applied, singly and in various combinations. The efficacy of the protocols was evaluated by fluorescent photography and analysis of residual MS from skin/hair swabs, decontamination materials and air samples. Results: Dry decontamination was effective, with the greatest reduction in skin and hair contamination arising from the "Triple Protocol" (DD+LPS+TD). Secondary hazards associated with contaminated individuals and equipment decreased as the number of decontamination procedures increased. In particular, dry decontamination reduced the potential contact and inhalation hazard arising from used washcloths, towels and vapor within the TD units. Discussion: The introduction of dry decontamination prior to wet forms of decontamination offers a simple strategy to initiate treatment at a much earlier opportunity, with a corresponding improvement in clinical outcomes and substantial reduction of secondary hazards associated with operational processes.

Comparison of Measurement Methods for Dermal Exposure to Hazardous Chemicals at the Workplace: The SysDEA Project

There is a principal need for more precise methodology with regard to the determination of occupational dermal exposure. The goal of the Systematic analysis of Dermal Exposure to hazardous chemical Agents at the workplace project was therefore to generate scientific knowledge to improve and standardize measurement methods for dermal exposure to chemicals at the workplace. In addition, the comparability of different measurement methods was investigated. Different methods (body sampling by means of coveralls and patches, hand sampling by means of gloves and washing, and head sampling by means of headbands and wiping) were compared. Volunteers repeatedly performed a selection of tasks under standardized conditions in test chambers to increase the reproducibility and decrease variability. The selected tasks were pouring, rolling, spraying, and handling of objects immersed in liquid formulations, as well as dumping and handling objects contaminated with powder. For the chemical analysis, the surrogate test substance Tinopal SWN was analyzed by means of a high-performance liquid chromatographic method using a fluorescence detector. Tinopal SWN was either applied as a solid product in its pure form, or as a low and high viscosity liquid containing Tinopal SWN in dissolved form. To compare the sampling methods with patches and coveralls, the exposure values as measured on the patches were extrapolated to the surface areas of the respective parts of the coverall. Based on this extrapolation approach, using the patch method resulted in somewhat higher exposure values compared to using a coverall for all exposure situations, but the differences were only statistically significant in case of the liquid exposure situations. Using gloves resulted in significantly higher exposure values compared to hand wash for handling immersed objects, rolling, and handling contaminated objects, and slightly higher (not significant) exposure values during pouring and spraying. In the same context, applying wipe sampling resulted in higher exposure values than using a headband, which was at least partly due to extrapolation of the wipe results to the surface area of the headband. No ‘golden standard’ with regard to a preferred measurement method for dermal exposure could be identified from the methods as investigated in the current study.