Ion exchange addition product of the montmorillonite clay, bentonite, q.v., and quaternium-18, a dimethyl, ditallow quaternary ammonium salt containing predominantly C18 alkyl chains. Acts as a barrier to block urushiol, q.v., from the skin. Prepn of aliphatic ammonium bentonites: E. A. Hauser, US 2531427 (1950); and organophilic properties: J. W. Jordan, J. Phys. Colloid Chem. 53, 294 (1949); idem et al., ibid. 54, 1196 (1950). Use as stationary phase in GSC and HPLC: D. W. Grant et al., J. Chromatogr. 99, 721 (1974). Description of properties, toxicology and use in cosmetics: J. Am. Coll. Toxicol. 1, 71-83 (1982). Clinical trial in poison ivy/oak dermatitis: J. G. Marks, Jr. et al., J. Am. Acad. Dermatol. 33, 212 (1995).
Barrier for the prevention of allergic contact dermatitis.