Testing of chemicals by evaluation of their distribution and degradation patterns in an environmental standard system.

Due to the EC directive 79/831 of September 18, 1979, and the German law on hazardous substances, the submission of test data on physical--chemical properties of new substances is mandatory for their registration. These data are supposed to predict in which compartments (air, water, soil, vegetation) the substance will primarily accumulate if it enters the environment. To calculate the distribution of a substance in the environment compartments, different mathematical models have been developed by several working groups, but have not yet been verified in practical experiments. During a prolonged period, the distribution of substances in the environment compartments has been investigated by experiments in an environmental standard system; design and function are explained. Distribution and degradation patterns of 12 reference substances will systematically be investigated, covering a wide spectrum in regard to their physical--chemical properties. Up to now 7 substances have been investigated under standard conditions. The distribution patterns established in these experiments are presented and compared with those obtained mathematically by use of the presently discussed stationary distribution models and values for the physical--chemical properties of the tested substances. The time alterations observed in the distribution patterns are interpreted by a kinetic model which will be part of the calculation method which is presently being developed on the basis of the obtained test values. The good consistency of distribution patterns established by experiments with those established mathematically justifies the assumption that a reliable calculation method of distribution patterns can be submitted as soon as our current work will be finished.