Such plastic boxes cannot be used for food. There is no triangle mark on the bottom of the plastic cup. If there is a material mark or description on the certificate label, it can be used. If there are none, it means that the material of the product cannot directly contact food. This type of container can only be used as a vase, flowerpot, storage container, etc. The triangular logo on the bottom of the plastic cup has the numbers 1-7 inside. Different numbers represent different materials.

1. The number "1" represents polyethylene terephthalate, or PET. Usage: Mainly used in mineral water bottles, carbonated bottles, juice drink bottles, soy sauce and vinegar bottles, etc. 2. The number "2" represents high-density polyethylene, or HDPE. Usage: HDPE is made into composite films with other plastics and is also used in aquatic products.

3. The number "3" represents polyvinyl chloride, or PVC. Usage: Used to manufacture intravenous infusion bags and disposable sterile infusion equipment. 4. The number "4" is low density polyethylene, 5. The number "5" is polypropylene, that is, PP. Usage: First, it is used as a container, which can be used as a microwave lunch box; second, it is used as a packaging film, which is often used for packaging snacks, bread, fruits, etc. 6. The number "6" is polystyrene, that is, PS. Usage: PS is mainly processed into films and foam plastics for packaging.

Films are used for packaging fruits and vegetables, and foam plastics are mostly used for bowls of instant noodle boxes and fast food boxes. 7. The number "7" is polycarbonate, that is, PC or other plastics. Purpose: Plastic containers made of PC material. Do not heat or expose them to direct sunlight during use, otherwise toxic bisphenol A may be released. The higher the temperature, the more and faster the release of bisphenol A will be.