compostable cutleries supplier Look at the numbers in the bottom triangle: No. 1 PET: Heat to 65 ° C, cold resistance to -20 ° C. No. 2 HDPE: Do not recycle. No. 3 PVC: Best not to buy. No. 4 LDPE: Heat resistance is not strong. No. 5 PP: Microwave lunch box, fresh-keeping box, high temperature resistance 120℃. No. 6 PS: Heat and cold resistant, can not be put in the microwave. No....