4. For regulation 6(1) (treatments and additions for natural mineral water) there is substituted—
“(1) A person shall not subject natural mineral water in its state at source to—
(a)any treatment other than—
(i)an authorised ozone-enriched air oxidation technique;
(ii)the separation of its unstable elements, such as iron and sulphur compounds, by filtration or decanting, whether or not preceded by oxygenation, in so far as the treatment does not alter the composition of the water as regards the essential constituents which give it its properties;
(iii)the total or partial elimination of free carbon dioxide by exclusively physical methods; or
(iv)an authorised activated alumina treatment; or
(b)any addition other than the introduction or the re-introduction of carbon dioxide to produce effervescent natural mineral water.”.