US Regulations

Water Purification Tablets must comply to the following US regulations:

Environmental Protection Agency (EPA):
Visit the website of the EPA

NSF/ANSI:
Visit the website of The American National Standards Institute (ANSI)

Food and Agriculture Organization:
Visit the website of The American National Standards Institute (ANSI)

European Regulations

Water treatment chemicals and filter media used for the preparation of drinking water by water suppliers in the UK must be show to comply with the European Standards published as the BS:EN series. This is a requirement of the Drinking Water Inspectorate (Regulation 25 Letter 11/2000).
European standard EN12931:2000