Chlorinated organic matter is formed during chlorine bleaching of carbohydrate. After chlorine bleaching of various cellulosic materials, organochlorine is found in the cellulose substrate (e.g., about 490 μg Cl/g substrate for cotton cellulose) as well as in the spent bleaching liquor. Some organochlorine is mineralized by alkali treatment of the cellulose and some is dissolved. Some organochlorine is not removed by exhaustive extraction with organic solvents, i.e., is inextractable. The carbohydrate-originated organochlorine accounts for part of the inextractable organochlorine in fully-bleached chemical pulp (previously ascribed entirely to a lignin origin). Chlorination of unmodified simple sugars results in some organochlorine (17 to 83 μg Cl/g sugar), while chlorination of “kraft-cooked” glucose precipitate results in 6150 μg organochlorine as Cl/g substrate. Household hypochlorite bleaching of cotton fabric also results in formation of inextractable organochlorine.