As additives or recycled materials are added into plastic products, the odor of ethylene, hydrogen sulfide, sulfur dioxide, amine, ammonia or other odor are carried in the plastic products. Some of the odors are released after the products are stored for a period of time; sometimes they are hidden in the plastic products, and these harmful gases are released during the secondary processing, forming the peculiar smell of plastics. Typical solutions to odors include adding gas sorbents and antibacterial agents to plastics to prevent the formation of unpleasant odors caused by bacteria and fungi. Residual odor can also be reduced by solvent extraction and exhaust.