Twelve dead. Nine hundred and eighty injured with about 500 victims requiring hospital admission. Those were the direct casualties of unprotected Tokyo civilians during the sarin subway attacks in 1995. First responders and hospital staff were still injured by secondary exposure even though they were better prepared and forewarned that some type of poisoning attack had occurred. The continued presence of agent on the surfaces of subway equipment at the attack site, whether contacted by touch or from off-gassing from those surfaces, caused injury to 135 of nearly 1,400 first responders. One hundred and ten (about 50%) of the hospital staff treating the injured also reported symptoms (e.g., vision impairment, headaches) of chemical weapons poisoning. Undoubtedly contributing to the injuries of the medical care providers was secondary contact with contaminated items (clothes, bags, phones, etc.) that traveled with the victims.
All the issues faced in this real-world attack are faced by warfighters at the site of an attack, as well as decontamination response teams, and medical staff treating injured soldiers. As seen by the numbers above, most casualties are injuries, not fatalities. Any improvement in the speed that such chemical warfare agents are decontaminated will not just save lives, but reduce the severity and number of injuries, which will allow field operations to continue at greater effectiveness. To achieve this goal, Reactive Surfaces has developed a line of coatings – WMDtox – containing enzymatic additives that immediately begin decontamination of organophosphorus chemical weapons agents on surfaces. Designed as a thin clear coat, WMDtox is capable being applied to the variety of surfaces common to a warfighter’s environment, and its decontamination capability has been demonstrated on objects typically touched by soldiers, decontamination personnel, or medical staff.
The four objects selected for demonstrations of the coating capabilities included a vehicle door handle, a small arms pistol, a section of a uniform and an iPad to represent handheld electronic equipment. These items were coated with WMDtox or an identical coating lacking the enzymatic additive, and then contaminated with the chemical warfare agent E605-0 variant. After allowing the items to self-decontaminate for one hour, they were placed in separate enclosed glass containers having hundreds of living fruit flies. Fruit flies, like humans, are susceptible to poisoning by organophosphorus compounds and served as a living model for the effectiveness of the coating’s decontamination capability. The flies were allowed to crawl and fly freely within the confines of the glass chamber for three hours in each case (only one hour in the case of the iPad) to give them ample opportunity to contact all the different areas of each object, and thus any chemical agent remaining on the objects’ surfaces. At the end of the contact period, the percentages of the fruit flies that survived were tallied.
The greatly enhanced survivability of fruit flies benefiting from contacting the self-decontaminating WMDtox door handle versus the control coating is shown in the photo.
The beige painted door handle on the left is over coated with a control clear coat lacking the enzymatic additive, while the door handle on the right is over coated with the WMDtox coating. After three hours, contact with the chemical warfare agent E605-0 variant remaining on the inactive control coating has killed virtually all the flies, while the WMDtox coating on the right has destroyed the E605-0 toxin effectively enough to result in near full survival of the flies.
These results are consistent with earlier studies conducted by NATO using live chemical agents (soman, and VX) that demonstrated self-decontamination activity in time frames as little as less than an hour. However, depending upon the coating system used, the current forms of WMDtox are several-fold to more than ten-fold more active than the coating systems used in these previous third-party studies. Though the coating formulation and details regarding the enzymatic additive are proprietary, they can be varied to best suit different organophosphorus chemical agents, substrates and operational environments. WMDtox typically is provided as a three-component polyurethane with a wet cream-colored liquid and dries to a clear matt gloss coating. The coating is rapidly applied by HVLP spray equipment, and has a surface coverage of over 1900 square feet per gallon. Substrates suitable for the current clear coat formulation include textiles, exterior and interior architectural surfaces, exterior and interior vehicle and aircraft surfaces, electronic equipment including those controlled by touchscreens, and military equipment currently coated with standard CARC by addition of WMDtox as a CARC-compatible topcoat. Though the military has the most pressing need to self-decontaminate equipment in service, WMDtox is also available for use to other branches of the government as well as first responders.