Vapor Lewisite

Caution Contact with Lewisite vapor or liquid can be fatal. Do not breathe the fumes Skin contact must be avoided at all times. If inhalation is a possibility, hold breath until respiratory mask is donned. Firefighters should wear full protective clothing and respiratory protection during both fire-fighting and rescue (positive pressure, full face, NIOSH-approved self-contained breathing apparatus/SCBA shall be worn). 

Liquid lewisite applied by eye-dropper to the forearms of men caused blanching and discoloration of the skin followed by extensive erythema within 15 to 30 minutes and vesication within 12 hours or less (Wardell, 1941, as cited in Goldman and Dacre, 1989). The pain associated with these dermal exposures reportedly occurred within two minutes and considerable discomfort persisted for about one week. Other tests with human subjects and clinical reports also indicate a similar temporal sequence of events. Exposure to lewisite vapor (0.06 to 0.33 mg/L) caused discoloration and blistering with the maximum effect occurring by 36 to 48 hours after exposure (Wardell, 1941). At a concentration of 0.01 mg/L, lewisite vapor caused inflammation of the eyes and swelling of the eyelids after 15 minutes of exposure, and inhalation of 0.5 mg/L for five minutes is considered to be potentially lethal. 

Short-term exposure (10 to 30 minutes) of dogs to lewisite vapor (0.05 to 0.12 mg/L) produced vomiting, urination, defecation, and severe respiratory distress that resulted in the death of 80% of the dogs within 3 to 48 hours (Goldman and Dacre, 1989). It was not reported whether the exposures were whole body or head only. 

Eldridge (1923) conducted tests on human volunteers to assess the effects of dermal exposure to lewisite vapor. The arms of men (one to seven men with previously determined average sensitivity to lewisite) were exposed to varying concentrations of lewisite vapor for periods ranging from... 

Lewisite is readily absorbed from the skin, eyes, and respiratory tract, as well as after ingestion and through wounds. It causes blistering on the skin and mucous membranes on contact. After absorption, it causes an increase in capillary permeability, which produces hypovolemia, shock, and organ damage. Unlike the mustard agents, lewisite vapor or liquid causes immediate pain or irritation although lesions require up to 12 h to become full-blown cases. 

The toxicity of Lewisite vapor is very similar to that of mustard vapor (Houck et al., 1947 Trammel, 1992). Blister fluid from a Lewisite-caused blister is nonirritating however, it does contain 0.8-1.3 mg/mL of arsenic and in some instances intact Lewisite or equally damaging breakdown products have been found in blister fluid (Buscher and Conway, 1944 Trammel, 1992). 

A person is less likely to receive severe eye injury from Lewisite vapor than from mustard vapor because the immediate irritation and pain caused by Lewisite will produce blepharospasm, effectively preventing further exposure. A small droplet of Lewisite (0.001 mL) can cause perforation and loss of an eye (Mann et al., 1946). 

Lewisite vapor is extremely irritating to the nose and lower airways, causing individuals exposed to it to seek immediate protection, thus limiting further exposure. The airway lesion of Lewisite is very similar to the lesion caused by mustard exposure except that the Lewisite vapor is extremely irritating to the mucous membranes. In large amounts. Lewisite causes pulmonary edema. 

The toxicity of Lewisite vapor is very similar to that of mustard vapor the LCt50 (the concentration time that is lethal to 50% of the exposed... 

If you breathe Lewisite or Mustard-Lewisite vapors, your airways will immediately become irritated. You could experience burning pain in the nose and sinuses, laryngitis, cough, shortness of breath, nausea, and vomiting. You could also experience airway tissue damage and accumulation of fluid in your lungs, which could result in death. 

Contact of the skin with Lewisite or Mustard-Lewisite vapors or liquid will result in local pain, swelling, and rash, followed by blistering that might be delayed for hours. If Lewisite or Mustard-Lewisite vapors or liquid contact your eyes, you will suffer immediate pain and rapid svvelling. as well as seriou.s damage to the cornea and other parts of the eye. 

Lewisite vapor is heavier than air, so it will settle in low-lying areas. 

The toxicity of lewisite to a variety of phytoplankton and aquatic plants (water milfoil, parrot s feather, and water crowfoot) was tested in static 30-d tests at concentrations of 5 and 50 mg/L (Buswell et al. 1944). At 5 mg/L, lewisite inhibited the growth of the phytoplankton, and the water milfoil and water crowfoot died at 50 mg/L, all plants died. Lewisite vapor is extremely phytotoxic and has been implicated in the death of vegetation in lewisite shell target areas (Armstrong et al. 1928). 

While the toxicity of Lewisite is roughly the same as mustard, the action of Lewisite on the skin causes an immediate burning sensation, and its odor is readily apparent. Severe damage to the eyes occurs almost immediately after exposure, while Lewisite vapors irritate the mucosa of the nasal and upper respiratory system. Lewisite is subsequently absorbed into the body, and distributed as a systemic poison to various organs. 

Eldridge (1923) conducted tests on human volunteers to assess the effects of dermal exposure to lewisite vapor. 

Mouret et al. (2013) reported that for the SKH-1 hairless mouse model, topical application of dimercapto-chelating agents such as BAL and meso-2,3-dimercaptosuccinic acid (DMSA) were more effective than subcutaneous administration in the attenuation of lewisite vapor-induced injury. Although both agents reduced neutrophil infiltration, wound size, and necrosis of the skin barrier, BAL was found to be more effective than DMSA. 

Rapid for vapor and dissolved Lewisite-1. Low solubility in water limits the hydrolysis. 

Rapid hydrolysis aids in lowering the duration of effectiveness of toxic chemical agents. For example, in the presence of water or water vapor, lewisite (L) rapidly hydrolyzes. Therefore, it has a shorter duration of effectiveness than distilled mustard (HD). 

Agent vapors of both series cause eye irritation. However, there is no significant difference in the concentration that will irritate the eyes and the one that will produce eye injury. Although impacts from exposure to vesicants occur almost at once, contact with vapors or the liquid agent neither irritates the skin nor produces visible dermal injuries until after a substantial latency period. In contrast, HL (C03-A010), sulfur mustard mixed with lewisite, produces immediate pain due to the arsenic mustard component. 

Laboratory grade agents are typically colorless oily liquids or solids. They have little or no odor. Salts of nitrogen vesicants are typically white odorless solids. High concentrations of vesicants can cause eye irritation. Because of the lewisite (C04-A002) component, HL (C03-A010) vapors cause immediate irritation to the eyes, nose, throat, and skin. 

Blister agents such as distilled mustard (HD) and nitrogen mustard (HN) have a slow rate of action and might be persistence for three days to one week in warm weather and for some weeks in cold weather, while lewisite (L) and mustard/lewisite (HL) have a quick rate of action and would be persistent for one to three days during summer and for weeks during winter. Route of entry for these blister agents would be nearly the same eyes, lungs, and skin for vapor or aerosol, but for liquid, the points of entry would be the eyes and skin for HD and HN and eyes, skin, and mouth for L and HL. 

The hazard of a mixture of mustard and Lewisite (HL) on the eyes and skin, or vapor in the eyes or respiratory tract, is immediate. Within an hour, edema of the conjunctivae and lids begin and soon results in eye closure. Any casualty experiences serious pain seconds after contact with HL liquid, but such extreme pain makes the injured person decontaminate at once. Rapid decontamination is the sole manner to avoid severe burns since after a few minutes of contact with a mixture of mustard and Lewisite, the upper layer of skin will die and appear gray, painful erythema will be apparent shortly thereafter, and... 

Thioether. Mustard agent received its name because of garlic, horseradish, or mustard odor that can be detected by smell. The human nose can detect mustard (H, HD) in concentrations of 0.6 to 1.0 mg/m3. It must be understood that until recently, the U.S. military had no automatic vapor/liquid detection capability. Therefore, alert soldiers would most likely smell the agent vapor before encountering the liquid (after release, H or HD appears as a thick, colorless or pale yellow liquid HL, or mustard/lewisite mixture, appears as a dark oily cloud that can be detected visually). 

---