This part of BS 6920 describes methods designed to assess the ability of a non-metallic product to affect hot and boiling water intended for human consumption by imparting a discernible odour or flavour, or any noticeable colour or turbidity. It is also applicable in assessing the leachability in hot or boiling water of metals from non-metallic products and the extraction from such products of substances that may be of concern to public health. It is not applicable to the test for growth of aquatic microorganisms (see BS 692-2.4). Products used exclusively in industrial or steam services are excluded.