A protective agent suitable to protect the human skin against lesions caused by vesicants or other percutaneous chemical agents, particularly against sulfur mustard gas injury and VX intoxication, which comprises a protective-effective amount of a hydrophilic water-based cream, alone or together with one or more additives selected from among the group consisting essentially of polyols, mono-, oligo- or polysaccharides, and salts of organic or inorganic acids. The additive polyol may be glycol, propylene glycol, polyglycerol, glycerin, sorbitol, dulcitol, tritol, sorbitol or mannitol. The additive monosaccharide may be ribose, xylose, glucose, fructose, galactose or mannose. The additive oligosaccharide may be sucrose, maltose, lactose, raffinose or cellobiose.