Toxicology of Riot Control Chemicals - CS, CN and DM

Abstract

The volunteers in thece tests are enlisted US Army personnel. These tests are governed by the principles, policies, and rules for medical volunteers as established in AR 70-25. DIGESTThis report summarizes information on the physiological and toxicological effects of three riot control agents: CS, o-chlorobenzalmalononitrile; CN, chloroacetophenone; and DM, dimethyl aminochloroarsine. Included in the report is a review of the toxicity tests conducted on the old compounds CN and DM by various organizations from 1918 to the present, and on CS from 1958 to the present. Detailed results of experiments conducted by the Toxicology Department, Medical Research Laboratory, by various methods on animals of several species are given. Based on the animal experiments, estimates are given for lethal doses in man. Incapacitating doses P.e determined and reported on the basis of tolerance times of volunteers exposed to aerosols of th[e three compounds. Safety fac..ors, dern ed from ratios of estir, ated lethal doses to bncapacitatipg dimes, are reported for the three compour•ds, P CONTENTS

Riot control agents: pharmacology, toxicology, biochemistry and chemistry

“…6,60 Local application of DM to rabbit eyes resulted in conjunctivitis, blepharitis and corneal opacity. 61 Ballantyne 29 described the ocular effects of human inhalation exposure to DM, consisting of lacrimation, blepharospasm and eye pain. Additionally, DM has been noted to produce necrosis of the corneal epithelium in humans.…”

“…The additives prevent agglomeration and produce a free-flowing powder that can be dispersed from powder formulation devices. 61 Chlorobenzylidene malononitrile, a peripheral sensory irritant, is highly irritating to mucous membranes that cover or line tissues of the eyes, nose, throat and stomach. Ocular effects of CS include intense irritation, excessive tearing, conjunctivitis, discomfort and pain and uncontrolled blinking (blepharospasm).…”

“…The terms LCt 50 and ICt 50 describe the airborne dosages that are lethal (L) or incapacitating (I) to 50% of the exposed population. A number of animal studies on CS have been reviewed and summarized in a report by McNamara et al 61 Various animal species were exposed for 5-90 min to CS aerosols that were generated using various dissemination techniques. Toxic signs observed in mice, rats, guinea-pigs, rabbits, dogs and monkeys on acute exposure to CS were immediate and included hyperactivity followed by copious lacrimation and salivation within 30 s in nearly all species.…”

“…The toxicology of CN has been reviewed and summarized by McNamara et al, 61 National Academy of Sciences in a report 6 and by Hu et al 249 Early toxicity studies on CN were highly variable, and studies subsequently conducted in the mid-1960s in various animal species were designed to provide more quantitative data. In these studies, CN was dispersed in acetone or from commercially available thermal grenades.…”

“…Exposure to high concentrations of this material can result in serious illness as a result of pulmonary damage and edema or death. 250 A number of investigations on the physiological effects of DM in various species of animals, including primates, have been conducted and the findings are summarized in reviews by McNamara et al 61 and Owens et al, 251 as well as in a National Academy of Sciences report. 6 Acute exposure to DM results in hyperactivity, ocular and nasal irritation, salivation, labored breathing, ataxia and convulsions.…”