Recently the issue of in-house laboratory testing vs independent laboratory testing has been in the media. IANZ is the external body that assesses laboratories to ensure their testing meets the standard ISO 17025 for good laboratory practice. They ensure that equipment is calibrated and traceable to international standards and that tests are completed to the test methods accurately. They ensure inter-laboratory tests (round robin) are completed and any outlying results are followed up on. Company laboratories should be able to create reliable, accurate results, and IANZ accreditation gives customers assurance that these tests can be relied on. The equivalent body to IANZ in Australia is called NATA.
With paint, internal laboratories test each batch of product before it is released into the market, however, the specifications are set by the company. Premium brands will have higher and tighter specifications than house brands. Paint needs to meet the requirements of the relevant consumer protection laws and any warranty / guarantees promised.
In addition, an external body called APAS (Australasian Paint Accreditation Scheme) creates minimum standards for paint and coatings. If products meet these standards, they can be given APAS approval. Some products in NZ meet and are approved to APAS standards.
The subject of laboratory testing and accreditations can be dry, but recent media attention has highlighted how important the quality of the materials in the construction industry are and the risks with lower quality products and testing regimes.