The environmental effects on the fading behavior of monochlorotriazinyl reactive dyes on dry cotton fabrics when exposed to an atmosphere of nitrogen, oxygen, and air were studied, Most dyes showed a two step fading behavior, i.e. an initial and then smaller subsequent fading. Many of the dyes examined underwent the largest fading in oxygen, but a phthalocyanine dye showed it in a nitrogen environment. With an increase in the concentration of oxygen, the initial fading of almost all of the dyes increased, On exposure in air, some dyes showed an initial oxidative fading followed by a reductive fading, while the fading for a phthalocyanine dye and for CI Reactive Blue 2 decreased in nitrogen, i.e. a suppressive effect of oxygen on reductive fading. (C) 1998 Elsevier Science Ltd.