Anaerobic biodegradation test under sludge digester conditions (AnBUSDiC)

Summary

A simple, reliable test system for anaerobic biodegradation of surfactants has been established, that spurs innovation within the industry by facilitating the screening of new as well as of existing molecular structures. Two publications in peer-reviewed journals have proven to be key in gaining acceptance by national competent authorities (e.g. in France and Denmark) on a case by case basis.

Background

Within the European Ecolabel scheme anaerobic biodegradation plays a pivotal role with respect to the assessment of surfactants (e.g. as a pass/fail criteria). However, the standard OECD test method (OECD Test No. 311 – Anaerobic Biodegradability of Organic Compounds in Digested Sludge by Measurement of Gas Production) has severe limitations, specifically that it is time consuming, difficult to handle, and – most importantly – prone to false negative results. ERASM made the EU Commission aware of the limitations of the standard test. Against this background, ERASM initiated the development of a new anaerobic test procedure, that is easier to operate and acceptable to the regulators.

Outcome

The current standard test for anaerobic biodegradation (OECD 311) has severe shortcomings for the industry. With the AnBUSDiC test, a simple but efficient test system was developed as an alternative to standard tests. The reliability of the test procedure was confirmed in a ring test involving seven international laboratories. The AnBUSDiC test is used by member companies for testing the anaerobic biodegradability of surfactants. The resulting data have been successfully used for regulatory purpose, i.e. to demonstrate anaerobic biodegradability in the context of EU- and Nordic Swan Ecolabel applications.