Overview of the Standard
Product testing to AS/NZS 4020
The Standard requires that products do not affect the taste or appearance of water; do not support the growth of microorganisms; and do not release cytotoxic or mutagenic compounds or metals. The tests required are specific to the type of product submitted.
Appendix C - Taste of Water Extract
A trained panel tastes water extracts to determine whether products release any compounds that impart discernible taste.
Appendix D - Appearance of Water Extract
Water that has been in contact with a product is examined for any increase in colour or turbidity.
Appendix E - Growth of Aquatic Microorganisms
In a test that takes 8 weeks, products are examined for the ability to support bacterial growth by monitoring dissolved oxygen levels.
Appendix F - Cytotoxic Activity of Water Extract
Water extracts are tested for cytotoxicity using mammalian cell lines maintained in a laboratory culture. Any adverse effect on the health of the cells is recorded as a cytotoxic effect.
Appendix G - Mutagenic Activity of Water Extract
An AMES test is used to determine whether products release mutagenic compounds. Water extracts are mixed with specific bacteria. Any measured change in genetic nature of the bacteria is regarded as evidence of mutagenic activity.
Appendix H - Extraction of Metals
Water extracts are examined for the release of Arsenic, Antimony Barium, Cadmium, Chromium, Copper, Lead, Mercury, Molybdenum, Nickel, Selenium and Silver. The limits are in line with NHMRC guidelines. The extraction procedure is either by end-of-line test or in-line test.
Appendix J - High Temperature Tests
Products in contact with hot water are tested at higher temperatures. This applies to hot water systems, boiling water dispensers (including their outlet taps, fittings and tubes).