Decontamination 

Personnel

Once the skin has become contaminated with chemical warfare agent, it is critical to remove that agent as quickly as possible. The first step one should take is to flush the eyes with copious amounts of clean water. The next step is decontaminate the skin. The US military has two types of technology for this purpose.

The M258A1 kits contain two sets of wipes. DECON-1 wipes, wetted with 72
percent ethanol, 10 percent phenol, 5 percent sodium hydroxide, 0.2 percent ammonia, and 12.8 percent water are used first, followed by the DECON-2 wipes. Each DECON-2 packet contains a wipe impregnated with chloramine B and sealed glass ampoules filled with 45 percent ethanol, 5 percent zinc chloride and the 50 percent water. The ampoule is crushed into the wipe, which is then used to clean the affected area.

The more recently developed M291 kit contains six packets, each of which contains an applicator bag filled with Ambergard J XE-555 decontaminant resin. The dry resin is rubbed over the contaminated area and the resin absorbs any agent.

Equipment

In addition to personnel, equipment must be decontaminated. For some of the most volatile chemical agents, only aeration and ventilation are required for decontamination. For liquid agents with lower vapor pressures, however, treatment with some decontamination solution is required. By World War II, bleaches were commonly used as decontamination solutions:

• 2-6 percent aqueous sodium hypochlorite solution (household bleach)
• 7 percent aqueous slurry or solid calcium hypochlorite (HTH)
• 7 to 70 percent aqueous slurries of calcium hypochlorite and calcium oxide (supertropical bleach, STB)
• solid mixture of calcium hypochlorite and magnesium oxide (Dutch powder)
• 0.5 percent aqueous calcium hypochlorite buffered with sodium dihydrogen phosphate and detergent (ASH)
• 0.5 percent aqueous calcium hypochlorite buffered with sodium citrate/citric acid and detergent (SLASH)
  Other decontamination solutions include:
• caustic sodium hydroxide
• dilute alkali solutions
• steam and ammonia or hot, soapy water (for confined areas)
  Fire or extreme heat can be used to decontaminate heat resistant solid surfaces.
  Some of the systems currently used by the US Army for decontamination include:
• The M280 kit for use on personal equipment uses the same materials as the M258A1 personal decontamination kit: a set of towelettes wetted with 72 percent ethanol, 10 percent phenol, 5 percent sodium hydroxide, 0.2 percent ammonia, and 12.8 percent water are used first, followed by a second set of towelettes impregnated with chloramine B and wetted with 45 percent ethanol, 5 percent zinc chloride and the 50 percent water.
• The M13 portable decontamination apparatus, for use on vehicles and equipment, uses decontamination solutions number 2 (DS2): 70 percent diethylenetriamine, 28 percent ethylene glycol, monomethyl ether, and 2 percent sodium hydroxide. DS2 is less corrosive to metals than are the bleach-based decontamination solutions, but it can damage painted surfaces and plastics.
• The M295 Individual Equipment Decontamination Kit, uses the Ambergard J XE-555 decontaminant sorptive resin as the M291 kit for personal use.
  
  

• The M17 transportable decontamination system for equipment, vehicles, and personnel is capable of delivering water at temperatures up to 120 C and pressures up to 689 kPa.

Reference

Yang, Y.-C.; Baker, J. A.; Ward, J. R., Decontamination of chemical warfare agents, Chem. Rev., 1992, 92, 1729-1743.