On October 8th 2005 the Regulation (EC) Leitet Herunterladen der Datei einNo. 648/2004 on detergentes (consolidated version) came into force. The purpose is to harmonise the rules for the commercialization of detergents in the European internal market regarding biodegradability and labelling.

Hydrotox GmbH has analysed far more than 200 surfactants in the past years for customers of the chemical industry and has gained substantial experience and routine. The test capacity particularly of the standard and reference methods (CO2-evolution assay and CO2-headspace -assay) were adapted to customers’ needs, which are well-known producers from all over Europe (e.g. Germany, UK, Greece, Italy, The Netherlands, Spain).


One important modification of the regulation on detergents concerns requirements for the ultimate aerobic biodegradability of surfactants. Previously, the loss of surface-active properties has been a measure for the primary biodegradation of surfactants, according to the German “Tensidverordnung” (from 1977, 1986). Now, detergents have to comply with the criteria for ultimate aerobic biodegradation according to Annex III of the above new EU regulation, in order to be brought on the market without further limitation.

Several suitable methods for determining ultimate biodegradation are described in Annex V of the EU Directive 67/548/EWG, and in the OECD 301 test guidelines, respectively. Particularly the „CO2-evolution test, the so-called “modified Sturm test”), the „Closed bottle test” or the „Manometric respirometry test” determine the ultimate mineralisation of the test items. As a reference method for testing surfactants, the CO2-headspace-test has been chosen according to EN ISO 14593 (1999) or OECD 310 (2006).

Surfactants are considered as ultimately biodegradable if the measured level of biodegradability (mineralisation) is at least 60% in 28 days. Thereby, the “ten days window” principle for determining “readily biodegradation” is not applied.

If a detergent contains surfactants for which the level of ultimate biodegradation is lower than 60%, a derogation can be requested. One requirement for doing so is that the level of primary biodegradability is at least 80% according to Annex II of the regulation. The reference method used is based on the Confirmatory test (the laboratory activated sludge simulation test). Based on a risk assessment of persistent metabolites, done by comparing exposure and effects data, the application of surfactants may be acceptable for special industrial or institutional areas (see Annex IV of Regulation No. 648/2004). The principles of the procedure for performing a risk assessment have been described by the Commission in a Öffnet externen Link in neuem Fenster„Tiered Approach Guidance Document“ (Commission Recommendation C/2005/5677 of 23. December 2005).

Future Development

To adopt the EC regulation on detergents into national laws, central aspects of the German law for washing and cleaning agents have been changed in 2007. More updated information on the further implementation of the regulation on detergents on the European level can be found on the website of the Öffnet externen Link in neuem Fenster European Commission. The question, whether requirements on anaerobic biodegradability should be considered in the Regulation, is currently discusssed.

Hydrotox GmbH offers substantial laboratory and expert services for producers of detergents and surfactants, including the determination of the ultimate biodegradability, anaerobic biodegradation, and the studies and assessments needed for requesting derogation.