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).