Resin identification coding system
Resin identification coding system is introduced as a means of helping consumers and recyclers to identify the type of plastic resin from which a bottle or a container is produced from. Manufacturers follow the coding system by placing a number or SPI code on each plastic product and the code are usually molded into the base of the products. For example, plastics marked with an SPI Code of 1 are made with polyethylene terephthalate (PET).