2% impure Chief Medical Officer admits

I'm sure you all know but a reminder of what they would put into our water - it isn't very pure.

The UK's Water (Fluoridation) Act 1985, since incorporated into the 1991 Water Industry Act, allows hexafluorosilicic acid (H2SiF6) and disodium hexafluorosilicate (Na2SiF6) to be used to increase the fluoride content of water. The published Code of Practice on Technical Aspects of Fluoridation of Water Supplies (Department of the Environment, 1987) gives specifications for these substances and states that 'the product. ..must not contain any mineral or organic substances capable of impairing the health of those drinking water correctly treated with the product'. For H2SiF6, limits are given for a number of possible impurities, including for iron, heavy metals, sulphate, phosphate, and chloride. The specification for Na2SiF6 powder requires a minimum of 98% m/m of the pure chemical, and gives maximum limits for impurities, including heavy metals (as lead) and iron. No other substances are allowed to be used in the fluoridation process, other than an anti-caking agent (the identity of which must be disclosed) in the case of Na2SiF6. Synthetic detergents are not permitted.