If you are new to fluoride in water, look here for an introduction

Fluoride compounds used in the UK for fluoridation of public water supplies

European and UK water regulations

Very strict European and UK regulations govern what can be added to public water supplies.

All substances added to public water supplies must be on a list of approved substances issued by the Drinking Water Inspectorate under Regulation 31 of the Water Supply (Water Quality) Regulations 2000, and approved by the Secretary of State, who is ultimately responsible. (1)  Under these regulations, the Drinking Water Inspectorate actively enforces the required standards by undertaking regular checks. (2)

Compounds in Drinking Water Inspectorate list of approved substances for water fluoridation

Two compounds of fluoride are permitted for artificial fluoridation in the UK:

  • Hexafluorosilicic acid (H2SiF6) – also known as fluorosilicic acid

  • Disodium hexafluorosilicate (Na2SiF6) – also known as sodium fluorosilicate

Both these compounds are included in the Drinking Water Inspectorate’s list of approved substances.  They achieve the desired concentration of fluoride (1 part per million) reliably and safely, are specifically manufactured to exacting quality standards, and must meet Department of Environment purity specifications.

In Europe the permitted upper limit for fluoride in drinking water is 1.5 ppm (based on WHO guidelines).  The target level for water fluoridation schemes in the UK is 1 ppm.

  1. Her Majesty’s Government (2000): The Water Supply (Water Quality) Regulations 2000. Statutory Instruments 2000 No 3184. London: HMSO.

  2. Drinking Water Inspectorate (2005): Code of Practice on Technical Aspects of Fluoridation of Water Supplies 2005. London. HMSO.


Two compounds, one in liquid form and another in powder form, are approved under UK legislation for use in water fluoridation schemes.


The compounds, which are manufactured to exacting quality standards, achieve the target concentration of fluoride in water (one part per million) safely and reliably.