Chennai (Tamil Nadu) [India], May 3 (ANI/PRNewswire): SGS is pleased to announce that its laboratory in Chennai is recognized by the Zero Discharge of Hazardous Chemicals (ZDHC) Foundation to operate as ZDHC approved MRSL certification body to assess conformance to Levels 1, 2 and 3 of the Manufacturing Restricted Substances List (MRSL) v3.1