Based on the previously mentioned 7-level classification and labeling rules for plastics, the safety of plastic products can be determined from the following core dimensions:
Check Compliance Labels: Legitimate products must be printed with the words "Food Contact Use Only," material abbreviations, a triangular recycling symbol, and complete information on the manufacturer and applicable standards. "Three-no" products (products without any labeling) should never be purchased.
Identify Material Grades: Look for the numbers in the triangular label on the bottom of the bottle: 5 (PP), 7 (Tritan), and PPSU are recognized as high-safety materials; avoid 3 (PVC) and ordinary PC; 1 (PET) should not be reused in hot water; and 6 (PS) should not come into contact with high-temperature oils.
Check Appearance and Texture: Prioritize colorless, transparent products without printing. Products with black spots or impurities on the surface, that crack easily when folded, or that have a pungent odor are likely made from recycled waste and may contain excessive levels of heavy metals and plasticizers.
Check the compatibility with the usage scenario. Confirm the temperature resistance range of the material. For example, only PP material labeled "microwave safe" can be used in a microwave oven. Ordinary plastics should not be used to store high-temperature or high-oil foods for extended periods to avoid the release of harmful substances.
