I am keen to know whether Enviro Seal Packing from Fisher which usually complies to Fugitive Emission Class BM (100 ppmv) or Class AM(50 ppmv) achieved with bellows seal around the stem is also compliant with Class BH/AH as per table-1 of ISO 15848-1? Class BH/AH has no correlation with Class BM/AM which is mentioned in ISO 15848-1 and also in Fisher's Control Valve Handbook. I could not find anything in Fisher's documentation on packing which suggests that its environmental service packings (Enviro Seal/ISO seal) can comply with Class BH/AH.