Biodegradering

Tests for biodegradability:

OECD 306: Biodegradability in Seawater: Closed Bottle Method.

The test substance is added to nutrient enriched natural seawater in a closed bottle. The consumption of oxygen (BOD) is followed for a period of 28 days, and the result is calculated as a percentage of degradation relative to the theoretical oxygen demand.  Although the test is basically designed for water soluble substances, it can in principle also be applied for poorly water soluble compounds. The test period can be prolonged to 60 or 90 days.

Alternatively, a test that is specifically designed for poorly soluble substances may be run: the Marine BODIS-test (BOD-Test for Insoluble Substances).

The principle of this test method is also known as the “Two Phase Closed Bottle Test”, in that the closed bottle is only partly filled with the aqueous test mixture.  The content of oxygen in the gas (air) phase greatly increases the oxygen capacity of the test bottle. The test is adapted to seawater conditions in accordance with the OECD 306 method. The test period can be prolonged to 60 or 90 days.

OECD 301D: Biodegradability in freshwater: Closed Bottle Method.

The test substance is added to nutrient enriched freshwater and inoculated with micro-organisms collected from a domestic sewage. The consumption of oxygen (BOD) is followed for a period of 28 days, and the result is calculated as a percentage of degradation relative to the theoretical oxygen demand.  Although the test is basically designed for water soluble substances, it can in principle also be applied for poorly water soluble compounds. The test period can be prolonged to 60 or 90 days.The OECD 301D test is not yet covered by the GLP.