Medical Aspects of Chemical Warfare (2008) - The Black Vault

Riot Control Agentsrespiration (RD 50). 122 PS exposure in mice at the RD 50dose (8 ppm) for 5 days, 6 hours per day, results innasal lesions of the respiratory epithelium consistingof moderate exfoliation, erosion, ulceration, and necrosiscoupled with minor squamous metaplasia andinflammation. 116 Moderate ulceration and necrosis ofthe olfactory epithelium, coupled with serous exudatesand moderate lung pathology, were also observed. Collectively,the PS pathology was similar to that observedfollowing an RD 50exposure to chlorine and displayeda distinct anterior–posterior severity gradient. Thesignificant toxicity in the posterior nasal cavity followinginhalation of PS or chlorine was likely the resultof the agents’ low water solubilities, which preventedsignificant absorption in the anterior nasal cavity.The human toxicity of PS following inhalation isprimarily restricted to the small to medium bronchi,and death may result from pulmonary edema,bronchopneumonia, or bronchiolitis obliterans. 123 Aslittle as 1.3 ppm may cause respiratory irritation inhumans. 109 The NIOSH, OSHA, and ACGIH exposurelimit for PS is 0.1 ppm (time-weighted averageof 0.7 mg/m 3 ). 69 The NIOSH IDLH level of 2.0 ppm isbased partly on studies conducted in the early 1930sthat determined that a few-second exposure to 4 ppmrenders a man unfit for action. 69,112,124 Symptoms inhumans resulting from environmental or occupationalexposures to PS include pain (burning) and tightnessin the chest, shortness of breath, sore throat, dyspnea,irritation, asthma exacerbation, and cough. 111,112,125 Thelowest published toxic concentration in humans is 2mg/m 3 (unknown exposure time), which producedlacrimation and conjunctiva irritation, and the lowestreported human lethal dose is 2,000 mg/m 3 for a 10-minute exposure. 69Dermatological effects. Direct exposure of skin toPS leads to irritation, itching, rash, and blisters. 108,111,112The minimal dose required to cause these effects isunknown.Ophthalmologic effects. PS causes eye irritationbeginning at 0.3 to 0.4 ppm, which appears to be belowthe threshold of odor (approximately 1 ppm). 109,124,126Clinical symptoms of PS-induced ocular irritationinclude immediate lacrimation, pain, and burning. In1995 three dockworkers were exposed to PS that hadleaked from a shipping container. 111 All three victimscomplained of burning and stinging in the eyes. Additionally,in the 2003 Kern, California, exposures, ofthe 165 persons complaining of PS-induced reactions,99% (164) of them reported eye irritation (82% reportedlacrimation, and 54% reported pain or burning of theeyes). 112Gastrointestinal disturbances. Following ingestionof PS, a corrosive effect on the forestomach tissueis the principal lesion. 114 Rats exposed to PS (10–80mg/kg) for 10 days demonstrated corrosion of theforestomach with histopathological findings includinginflammation, necrosis, acantholysis, hyperkeratosis,and epithelial hyperplasia. In humans, acute exposureto PS in the atmosphere from environmental sourcesand occupational accidents has been associated withan unusual taste, stomach and abdominal cramping,abdominal tenderness, diarrhea, vomiting, nausea,difficulty swallowing, and in rare cases, bloodystools. 111,112Other physiological responses. Additional clinicaland toxicological observations associated with acute PSexposure in humans include neurological manifestations(headache, dizziness, and fatigue); cyanosis; generalneuromuscular tenderness; peripheral numbness;painful urination; chest wall pain; elevations in creatinephosphokinase; and low-grade rhabdomyolysis. 111,112Long-term effects and severe medical complications.Long-term or repeated exposures to PS areassociated with damage to the kidneys and heart,and may result in hypersensitivity to subsequent PSexposures. No adequate data is available to assess themutagenic, carcinogenic, teratogenic, or reproductivetoxicity of PS in humans. 60CN (1-Chloroacetophenone)CN is also known as Mace from its chemical name,methyl chloroacetephenone. The first chemical Maceproduct is widely regarded as the original tear gas. 127,128Although it is the trademarked name for CN, the term“mace” is commonly used generically to refer to anyRCA. After the United States entered the First WorldWar, American and British chemists investigated CNand found it to be one of the most effective lacrimatorsknown. Its lacrimatory effects and persistence wereequal to or slightly greater than bromobenzyl cyanide,and its chlorine was less expensive than bromine. CN isvery stable under normal conditions and does not corrodesteel. It is a crystalline solid that can be dissolvedin a solvent or delivered in thermal grenades.Physical Characteristics and DeploymentCN (CAS 532-27-4, also known as w-chloroacetophenone,a-chloroacetophenone, phenacyl chloride,2-chloro-1-phenylethanone, and phenyl chloromethylketone) is a gray solid with an apple blossom odor. Ithas a molar mass of 154.5, corresponding to a molecularformula of C 8H 7ClO (Figure 13-9). Its molar solubilityat 20ºC is 4.4 × 10 -3 mol/L (68 mg/100 mL) in water.Hydrolysis of CN is very slow in water even whenalkali is added. 71 Melting and boiling points are 54ºC457