Mustard gas has been used in chemical warfare for more than 100 years, yet scientists are still seeking the ideal antidote to counter its blistering—and potentially lethal—effects. Now, researchers from the US Army show that a dry, powdered form of hydrogen peroxide decomposes this hazardous agent and renders it nontoxic (ACS Appl. Polym. Mater. 2020, DOI: 10.1021/acsapm.0c00651). The powder could be incorporated into protective gear like face masks and gloves and degrade mustard gas on contact, safeguarding soldiers in situations where liquid treatments could cause problems, study author Christopher J. Karwacki says. Early efforts to detoxify mustard gas, bis(2-chloroethyl) sulfide, relied on corrosive, bleach-containing solutions. More recent tactics use lightweight, dry decontaminants that require solvents or buffers that can damage skin, clothing, and electronics. Peroxydone, an H2O2-based powder concentrate found in some toothpastes, is a promising alternative. This powder is made by anchoring H2O2 to poly(N-vinylpyrrolidone) (PVP), a stabilizing support polymer. H2O2-PVP oxidizes the toxic sulfide in mustard gas to benign sulfoxide. Previous efforts required water to release the peroxide and a salt to accelerate the reaction. In this study, the researchers added a dry molybdate salt to activate the peroxide without water. The dry reagent degraded 42% of a mustard gas sample in just 1 h and remained stable at temperatures exceeding 100 °C.