When purchasing plastic cups, follow the "look, smell, and squeeze" rule: a compliant cup should be free of black specks or impurities, and its labeling-including the product name, material, applicable standards, production date, manufacturer name, and address-should be clear and complete; it should have no unpleasant odor; and it should not deform easily when squeezed. Consumers are advised to purchase products made by reputable manufacturers through legitimate channels. Pay attention to the material specifications and avoid buying PC (polycarbonate) cups for infants or young children; also, check that gaskets and straws are made of silicone rather than PVC. Be cautious with cups marketed as "biodegradable," as some manufacturers mix non-biodegradable PP (polypropylene) plastic into starch-based or other biodegradable materials to cut costs, meaning the product cannot fully biodegrade. You can also refer to the number code on the bottom of the cup: for example, No. 5 (PP) offers good heat resistance, whereas No. 1 (PET) is heat-resistant only up to 65°C and is suitable only for cold drinks.
