Since the late 1980s, the plastics industry has included symbols on container packaging to aid in recycling resins. The seven symbols denote different resin types that cannot be mixed together when the packaging is recycled, which is why people whose municipalities or trash collection firms offer recycling may be asked to separate the different kinds of plastics.

 

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Choosing products in recyclable packaging is an important component of the green cleaning process. All of the plastic containers in the list below are made of hydrocarbons. As more plastic is recycled, manufacturers consume fewer petrochemicals, derived from crude oil, in making these packages.

The first three resins listed below — polyethylene terephthalate, high-density polyethylene, and polyvinyl chlorine — currently are the most widely recycled plastics in the United States.

The symbols are usually embossed on the bottoms or lower sides of containers. Images of each symbol and where these resins appear in packaging follows.

 

	PETE – Polyethylene terephthalate, found in soda and vegetable oil bottles and peanut-butter jars.
	HDPE – High-density polyethylene, bottles used to package milk, water, juices, and bleach.
	PVC – Polyvinyl chloride, used to manufacture plumbing pipes and detergent and cleaner containers.
	LDPE – Low-density polyethylene, used in six-pack rings and bread and sandwich bags.
	PP – Polypropylene, found in straws, screw-on lids, and margarine tubs.
	PS – Polystyrene, widely known by the trade name Styrofoam, used in foam cups, egg cartons, packing peanuts and building insulation.
	Other – Multi-layered plastics, such as ketchup and syrup bottles.

 

 

 

References:

Atomic Physics group, Princeton University Physics Department

Symbol images courtesy Packaging Graphics, St. Louis, MO