The possible cause and prevention of yellowing of stored garments has been determined, according to Du Pont textile chemist Kennith C. Smeltz. He told the American Institute of Chemical Engineers, meeting in Atlanta, that nitrogen oxides may react with butylated hydroxytoluene (BHT) antioxidant that has sublimed from polyethylene wrappings onto garments to form yellow 2, 6-di-tert-butyl-l, 4-quinone methide. He suggest that mills, warehouses, and stores reduce nitrogen oxide levels in air, that garments be wrapped in films that do not contain BHT, and that textile finishers use such nonvolatile acids as citric or glycolic to finish fabrics on the acid side. Alkaline textile finishes neutralize nitrous acid formed in the reaction, Smeltz says, thus shifting equilibrium toward production of the quinone methide.