Drinking water is water intended for human consumption. It must comply with national legislation. The national legislation for EU member states is based on the EU Directive 98/83/EC. Raw materials used for conditioning products must be in accordance with DIN EN standards and included in national positive lists if existing. DIN EN standards especially for 'chemicals used for treatment of water intended for human consumption' contain general description and purity criteria. The limits for conditioning products differ from country to country.

The purity of Siliphos and Siliphos II for the treatment of drinking water is in accordance with the EC-Standard (DIN EN 1208) as well as the requirements of the FAO/WHO Expert Committee on Food Additives (7th and 19th Report).

Further there are some approvals from various countries for using Siliphos in drinking water treatment.

• Siliphos II is NSF-listed since 1991 as 'Drinking Water Treatment Chemical'