ON THE ECOTOXICITY OF PAPER DYES

There are special regulations and legislation governing the manufactur e and application of paper dyes and the use of coloured paper. The deb ate on these substances focuses primarily on azo dyestuffs, which are a particularly important class of products for the paper industry. Inc reasingly stringent legislation has led to a number of developments ge ared to ensuring that even the chemical intermediates used in the prod uction of paper dyes meet current ecotox standards. There are already many products with proven technical properties and there is a sound sc ientific basis for the development of many others. One potential point of conflict that we see is achieving the economic basis required for successful marketing of products that meet today's ecotox requirements . Under current chemicals legislation, developing and obtaining approv al for new products is very expensive. However, the use of suspect che micals is out of the question, at any rate tor traditional suppliers. Azo dyestuffs are produced by diazotisation of aromatic amines followe d by conversion of the resulting diazonium compounds with coupling com ponents. Reductive splitting of these products, e.g. in the human orga nism, can generate aromatic amines. Consequently, ecotoxicological eva luation of these products is based on the aromatic amines they could r elease in reductive conditions. These days, it is generally recognised the sulphonated amines are not carcinogenic, Our paper dyes do not re lease any of the aromatic amines that are classified as carcinogenic i n the 1994 MAK list, even in reductive conditions. This paper aims to heighten awareness of recent developments.