Aquatic toxicity of selected chemicals as a basic criterion for environmental classification.

In order to protect public health and the environment, the EU legislation has proposed a classification of dangerous substances. Chemicals are classified according to physico-chemical as well as toxicological and ecotoxicological properties. Environmental classification is based on inherent harmful potential of a substance to organisms and on its environmental fate, that is, degradation and bioaccumulation potential. In this study, experimental data on acute and chronic toxicity to aquatic organisms and biodegradability and bioaccumulation data obtained from literature were used to classify arsenic (applied as As2O3), copper (applied as CuCl2), phenol and 1,4-butynediol. For this purpose, the "base set data" obtained from standardised test methods served as a convenient indicator of the inherent toxicity of tested chemicals. Additional data about environmentally relevant properties of arsenic and 1,4-butynediol could lead to a revision of present chemical classification and labelling.