Types of Plastics

Manufacturers follow a coding system and place a number, or SPI code, on each plastic product, usually molded into the bottom. This guide provides a basic outline of the different plastic types associated with each code number.

Plastic marked with an SPI code of 1 is made with polyethylene terephthalate, which is also known as PETE or PET. PETE-based containers sometimes absorb odors and flavors from foods and drinks that are stored inside of them. Items made from this plastic are commonly recycled.

The SPI code of 2 identifies plastic made with high-density polyethylene, or HDPE. HDPE products are very safe and are not known to leach any chemicals into foods or drinks. HDPE products are commonly recycled.

Plastic labeled with an SPI code of 3 is made with polyvinyl chloride, or PVC. PVC is not often recycled and can be harmful if ingested. PVC is used for all kinds of pipes and tiles, but it's most commonly found in plumbing pipes.

Plastic marked with an SPI code of 4 is made with low-

density polyethylene, or LDPE. LDPE is not commonly recycled, but it is recyclable in certain areas. It tends to be both durable and flexible. It isn't known to release harmful chemicals into objects in contact with it, making it a safe choice for food storage.

Consumers will find the SPI code of 5 on plastic items made with polypropylene, or PP. PP can be recycled, but is not accepted for recycling as commonly as PETE or HDPE. This type of plastic is strong and can usually withstand higher temperatures. Plastic marked with an SPI code of 6 is made with polystyrene, also known as PS and most commonly known as Styrofoam. PS can be recycled, but not efficiently; recycling it takes a lot of energy, which means that few places accept it.

The SPI code of 7 is used to designate miscellaneous types of plastic that are not defined by the other six codes. Polycarbonate and polylactide are included in this category and are difficult to recycle.