Evaluation of neutralized Chemical Agent Identification Sets (CAIS) for skin injury with an overview of the vesicant potential of agent degradation products

Vesication and skin irritation studies were conducted in hairless guinea‐pigs to determine the vesicant and skin irritation potential of chemically‐neutralized Chemical Agent Identification Sets (CAIS). The CAIS are training items that contain chemical warfare‐related material—sulfur mustard (HD), nitrogen mustard (HN) or lewisite (L)—and were declared obsolete in 1971. Animals were dosed topically with ‘test article’—neat HD, 10% agent/chloroform solutions or product solutions (waste‐streams) from neutralized CAIS—and evaluated for skin‐damaging effects (gross and microscopic). Product solutions from the chemical neutralization of neat sulfur mustard resulted in microvesicle formation. All agent‐dosed (HD or agent/chloroform solutions) sites manifested microblisters as well as other histopathological lesions of the skin. Waste‐streams from the neutralization of agent (agent/chloroform or agent/charcoal) were devoid of vesicant activity. Cutaneous effects (erythema and edema) were consistent with the skin‐injurious activity associated with the neutralizing reagent 1,3‐dichloro‐5,5‐dimethylhydantoin (DCDMH). Chemical neutralization of CAIS was effective in eliminating/reducing the vesicant property of CAIS containing agent in chloroform or agent on charcoal but was inefficient in reducing the vesicant potential of CAIS containing neat sulfur mustard.Copyright © 1998 John Wiley & Sons, Ltd.