To protect water, requires that installations for handling substances constituting a hazard to water must be built and operated in such a manner that no contamination of waters, or any other detrimental change in their properties is to be feared. To ensure this, substances used in such installations must be tested and classified for their water-hazardous properties. Classification is carried out on the basis of the Administrative Regulation on the Classification of Substances hazardous to waters into Water Hazard Classes (Verwaltungssvorschrift wassergefährdende Stoffe (VwVwS) ) of 17 May 1999. The amendment to the VwVwS of 27 July 2005 entered into force on 1 August 2005.
There are three water hazard classes (WGK):
1: low hazard to waters
2: hazard to waters
3: severe hazard to waters
Classification of a substance into Water Hazard Classes can result
- listing of the substance in annex 1 or 2 in the VwVwS,
- documented WGK-Documentation
according to annex 3 of the VwVwS.
The Office of Documentation and Information on Substances Hazardous to Waters at the Federal Environmental Agency receives the self-classifications of substances according to Annex 3 of the VwVwS. Originators are asked to fill in a form to document their self-classifications.
The WGK of a mixture should be determined according to Annex 4 of the VwVwS either by using a calculating rule and the WGK of each component of the mixture or on the basis of experimental test data generated with the mixture.
For classifications using the calculation rule it needs to be ascertained if the mixture contains carcinogenic components.
WGK-classifications of mixtures are not centrally collected and published.