Development of a Next Generation Military Skin Decontaminant: Initial Efficacy Studies of Zirconium Hydroxide

The potential use of chemical warfare agents on the battlefield is a continual threat for the warfighter. Therefore, ensuring they are deployed with the most effective countermeasures is important to preserve life and limit adverse health effects. This is an initial proof-of-concept study evaluating zirconium hydroxide as a potential skin decontaminant. Zirconium hydroxide is a metal oxide with proven ability to rapidly neutralise a range of chemical warfare agents. However, there are a paucity of studies assessing the potential for zirconium hydroxide to be used as a skin decontaminant. Initially, several formulations of zirconium hydroxide (Zr(OH)4) were evaluated using Strat-M™ membrane contaminated with a 2 μL droplet of neat sulphur mustard (HD), soman (GD) or VX. Zirconium hydroxide formulations were then applied to the contaminated substrate 5 min postexposure and remained in situ for 10 min. The optimal formulation was then evaluated using excised porcine skin and compared to the currently deployed decontaminant-Reactive Skin Decontamination Lotion (RSDL). Generally, the absorption of chemical warfare agents tended to be greater through Strat-M™ membrane than porcine skin. The administration of powders alone outperformed formulations containing carrier solvents (except for VX). The removal of HD, GD or VX from pig skin using Zr(OH)4 was just as effective as RSDL across all the chemical agents evaluated. This study has tentatively identified zirconium hydroxide as a potential skin decontaminant. However, significant further work using OECD 428 compliant systems is required to ensure efficacy over a range of exposure scenarios. Additionally, studies evaluating the biocompatibility of Zr(OH)4 are required to ensure that there are no adverse reactions as a result from application to the skin.