The approval according to DVGW W270 refers to the growth of microbial organisms on organic materials. The focus here is primarily on materials that come into contact with drinking water. Products that are to be used in drinking water systems in Germany must be approved in accordance with DVGW W270.
The German Technical and Scientific Association for Gas and Water (Deutscher Verein des Gas- und Wasserfaches e.V.) is the publisher of the requirements.
As with the elastomer guideline, the aim is to ensure that the system components do not have a negative impact on drinking water during the production, distribution or storage stages.