This standard provides a fundamental method for determining the mass of inorganic residues in plastic materials after high-temperature incineration, used to assess the purity of the material and the content of inorganic additives (such as fillers, flame retardants, etc.)-2. The general procedure typically involves weighing an appropriate sample, placing it in a suitable crucible, carefully carbonizing it on an electric furnace to avoid combustion, and then transferring it to a high-temperature furnace (muffle furnace). The sample is incinerated at a specified temperature (such as the recommended temperature for specific plastics or a general temperature range of 500°C to 1000°C) until complete ashing and constant weight are achieved-6. The core testing instruments primarily include a muffle furnace or a dedicated ash tester capable of precise temperature control-1, and must be paired with an analytical balance with an accuracy of one ten-thousandth and a desiccator for weighing and cooling-7. Additionally, some automated thermogravimetric analyzers or fully automated industrial analyzers can also efficiently perform this test-2.