AS/NZS 4020 Testing of products for use in contact with drinking water
– this is the main standard any rainwater tank product should comply with and be certified for. It ensures the requirements have been met for the suitability of rainwater tanks for use with potable water. This standard also applies to items such as pipes and fittings that will come into contact with your drinking water.
AS/NZS 4766 Polyethylene storage tanks for water and chemicals
– this standard specifies requirements for the design and manufacture of polyethylene storage tanks to reliably store water and chemical solutions under normal atmospheric conditions. You should only purchase polyethylene tanks from manufacturers independently certified to this standard.
AS 2070 Plastics materials for food contact use
– this standard is relevant, but really secondary to AS/NSZ 4020 since it doesn’t apply to the final tank product, but only any plastic materials (resins, granules and powders) used for manufacturing. It describes procedures to be followed during the various stages of processing by manufacturers of plastics items for food contact.