Certification standards are widely used to measure the conformance of chemical products. Rather than creating yet another standard, we decided to leverage the existing ones. We do this by measuring how well a standard can indicate a chemical product's conformance to the ZDHC MRSL. Certified standards can be accepted by ZDHC to certify a product's performance at one of ZDHC's three conformance levels. You can find more information on ZDHC Conformance Guidance here.