This standard specifies the quality control requirements for phthalic anhydride, including its safety information, sampling, test methods, inspection rules, marking, labeling, Encasement, transportation and storage. The molecular formula of phthalic anhydride is C < unk > H < unk > O < unk >, the relative molecular mass is 148.12 (according to the 2009 International Relative Atomic Mass), and the CAS number is 85-44-9. This standard is applicable to ensure the mass stability and safety of phthalic anhydride during production, storage and transportation. The normative documents involved in the standard include preparation and chroma determination methods for chemical reagents, general rules for sampling chemical products, and specifications and test methods for analytical laboratory water to ensure compliance with relevant safety and mass requirements.