Reactive Skin Decontamination Lotion (RSDL) Maintains Its Effectiveness against Cutaneous Applications of VX Nerve Agent for at Least 5 Years Past Its Expiration Date

Reactive Skin Decontamination Lotion (RSDL) is the primary product the US military has fielded to decontaminate cutaneous exposures to chemical warfare agents. RSDL is extremely effective at protecting guinea pigs against cutaneous applications of the nerve agent VX. The 24‐hour cutaneous LD 50 of VX in un‐anesthetized haired clipped guinea pigs is 140 µg/kg. When RSDL is used to remove VX two minutes after application the LD 50 is 7,310 µg/kg. But RSDL is expensive to field and has a limited operational life. In the summer of 2017 we addressed the question of reducing costs by comparing the effectiveness of two expired (2012, 2014) lots of RSDL, to a lot that expires in April 2020. We applied the LD 30 dose of 5,500 µg/kg to groups of n=12 and used the different batches of RSDL to remove the VX. There was no statistical difference in survival (n=10, 8 and 9) between the groups. The RSDL packets did change color as they aged, with the non‐expired RSDL having a bright yellow color, the RSDL that expired in January 2014 having a gray color and the RSDL that expired in April 2012 having a black color. Analysis of the various RSDL packets by proton, carbon and phosphorus NMR spectroscopy indicated that the difference in the component composition was not greater than 1%. To determine if protection was due to physical removal of VX we exposed two groups of n=4 to 5,500 µg/kg and 2,250 µg/kg of VX and used RSDL trainers to remove the VX. In the 5,500 µg/kg group all 4 animals died, and in the 2,250 µg/kg group 2 animals died. These results argue that RSDL can be effective past its expiration date and that the protection provided is not due entirely to physical removal. The views expressed in this abstract are those of the author(s) and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government. The experimental protocol was approved by the Animal Care and Use Committee at the United States Army Medical Research Institute of Chemical Defense and all procedures were conducted in accordance with the principles stated in the Guide for the Care and Use of Laboratory Animals and the Animal Welfare Act of 1966 (P.L. 89‐544), as amended. Support or Funding Information This research was supported by the Defense Threat Reduction Agency – Joint Science and Technology Office, Medical S&T Division. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .