Urticants

Urticants produce instant, almost intolerable pain. They cause local tissue destruction immediately on contact with skin and mucous membranes. Sensations range from mild prickling to almost intolerable pain resembling a severe bee sting. Direct contact of the agent with the skin produces a corrosive type lesion. Skin lesions may not fully heal for over 2 months. Inhalation of Urticant vapor can cause lung membranes to swell and become filled with liquid (pulmonary edema). Death may result from lack of oxygen. 

Urticants are hazardous through inhalation, skin and eye exposure, and ingestion. 

Skin impacts from Urticant vapor occur at concentrations as low as 0.04 ppm (10 minute exposure). Effects may become unbearable at a concentration of 0.6 ppm (one minute exposure). 

Eye impacts from Urticant vapor occur at very low concentrations. LC50S for inhalation of Urticants are as low as 69 ppm (10 minute 

Urticants produce immediate effects on skin and eyes. Pulmonary edema caused by inhalation of the agent vapor may be delayed for several hours. 

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Application of topical corticosteroids under occlusion, or UV therapy (PUVA, UVAl) has been reported to lead to dermatologic improvement in patients with CM [9]. Both are effective in reducing pruritus and urtication, but relapse typically occurs... 

The agents in this class are halogenated oximes. This class of agents is not specifically covered by the Chemical Weapons Convention. Because of the toxicity of the agents and lack of commercial application outside of limited scientific research, urticants would be prohibited based on the Guidelines for Schedules of Chemicals. 

Eyes are especially susceptible to urticants. In addition to immediate pain, urticants produce lesions and inflammation to the cornea (keratitis), which may progress to blindness. 

Inhalation of urticants can cause lung membranes to swell and become filled with liquid (pulmonary edema). Death may result from lack of oxygen. 

Urticants are also systemic agents and rapidly pass through the skin to affect susceptible tissue. Percutaneous absorption of liquids or solids can also produce pulmonary edema and blood clots in the lungs. 

Urticants are hazardous through any route of exposure including inhalation, skin and eye exposure, ingestion, and broken, abraded, or lacerated skin (e.g., penetration of skin by debris). 

Urticants have a penetrating and disagreeable odor detectable at very low concentrations. Even minimal exposure causes immediate irritation and pain of the eyes, nose, mucous membranes, respiratory system, and skin. Urticants pose a significant percutaneous hazard and are absorbed through the skin within seconds. 

Urticants produce immediate irritation and pain of the eyes, respiratory tract, and skin. Blanching, reddening of the skin (erythema), and hives develop within minutes of exposure. Blisters, localized tissue death (necrosis), and formation of scabs may be delayed for 24 hours or more. Systemic effects, including pulmonary edema, from either inhalation or percutaneous absorption of the agent, do not occur until after a substantial latency period. 

Urticants are relatively unstable and tend to decompose spontaneously unless stored at low temperatures. Below —4°F, they can be kept for extended periods. Solvents including 1, 2-dimethoxybenzene, ether, dioxane, nitromethane, and glycine act as stabilizers and may be added to help prevent decomposition of agents during storage. Agents can be stored in glass or enamel-lined containers. Urticants rapidly attack rubber and metals, especially iron. 

For military purposes, unmodified urticants are classified as nonpersistent. They decompose rapidly in soil, and after a short delay on most other surfaces and in water. 

Urticants, even solids, have relatively high vapor pressure and evaporation or sublimation rates are nearly the same as water. 

The rapid skin damage caused by urticants renders the skin more susceptible to subsequent exposure of any other toxic material or agent. 

Meat, milk, and animal products from animals exposed to or killed by urticants should be destroyed or quarantined until it has been tested and determined to be safe to consume. 

Unprotected feedstock (e.g., hay or grain) should be destroyed. Although leaves of forage vegetation could still retain sufficient urticants to produce effects for a limited time, urticants are relatively nonpersistent on surfaces and should rapidly decompose depending on the level of contamination and the weather conditions. 

Urticants rapidly react with metals, especially iron. Iron chloride, even in trace amounts, can cause explosive decomposition. These agents decompose slowly when dissolved in water. Dilute acids will retard the rate of decomposition. 

Urticants react violently with strong bases. Reaction with household bleach may produce toxic gases. 

Urticants produce hydrogen chloride (HC1), hydrogen bromide (HBr), or hydrogen iodide (HI), and hydroxlamines when hydrolyzed. 

Urticants can penetrate garments and rubber much faster than other chemical warfare agents. Structural firefighters protective clothing is recommended for fire situations only it is not effective in spill situations or release events and should never be used as the primary chemical protective garment to enter an area contaminated with urticants. 

Immediately dangerous to life or health (IDLH) levels are the ceiling limit for respirators other than SCBAs. However, IDLH levels have not been established for urticants. Therefore, any potential exposure to these agents should be regarded with extreme caution and the use of SCBAs for respiratory protection should be considered. 

Currently, there is no information on performance testing of chemical protective clothing against urticants. 

Because of the extreme dermal hazard posed by urticants, responders should wear a Level A protective ensemble whenever there is a potential for exposure to any solid or liquid agent, or to an elevated or unknown concentration of agent vapor. 

Urticants are very soluble in water and can be removed from most surfaces by washing with soap and water. 

Because of the vigorous reaction of urticants with caustics, household bleach is not an effective decontamination agent for large quantities of these materials. Reaction with hypochlorites, including household bleach, may produce toxic gases such as chlorine. 

Casualties/personnel Speed in decontamination is absolutely essential. Because of the rapid onset of effects and the speed with which urticants are absorbed through the skin, decontamination will not be entirely effective by the time the casualty experiences pain and blanching occurs. However, decontamination must still be done as rapidly as possible postexposure. Remove all clothing as it may continue to emit "trapped" agent vapor after contact with the vapor cloud has ceased. Shower using copious amounts of soap and water. Ensure that the hair has been washed and rinsed to remove potentially trapped vapor. To be effective, decontamination must be completed within 2 minutes of exposure. If there is a potential that the eyes have been exposed to urticants, irrigate with water or 0.9% saline solution for a minimum of 15 minutes. 

Small areas Ventilate to remove the vapors. If condensation is present, decontaminate the area with copious amounts of soap and water. Collect the agent and rinseate and place into containers lined with high-density polyethylene. Although urticants rapidly break down on most surfaces, removal of porous material, including painted surfaces, may be required to prevent agents that have been absorbed into these materials from migrating back to the surface and posing an extended hazard. 

Casualties/personnel Speed in decontamination is absolutely essential. Because of the rapid onset of effects and the speed with which urticants are absorbed through the skin,... 

The CDC has not published a specific case definition for intoxication by urticants. However, the general case definition for vesicants states "A case in which a vesicant is detected in biologic samples. The case can be confirmed if laboratory testing is not performed because either a predominant amount of clinical and nonspecific laboratory evidence is present or an absolute certainty of the etiology of the agent is known."... 

Urticant vapors are violently irritating to the eyes, nose, and respiratory tract and cause immediate pain. Very low concentrations can cause inflammation, lacrimation, and temporary blindness higher concentrations can cause corneal corrosion and dimming of vision. Inhalation causes runny nose, hoarseness, and sinus pain. 

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