Profiles in Garbage: Polyethylene Terephthalate

Polyethylene terephthalate (PET) is a plastic resin used to make bottles for soft drinks, salad dressings, fruit juices, peanut butter and other household and consumer products. PET also is used for film, sheeting for cups and food trays, oven trays and other uses.

PET is a relatively new packaging resin, first commercialized in the early 1970s. As an "engineered" resin, it is more expensive than commodity resins such as high-density polyethylene (HDPE) and usually is the highest valued plastic recyclable.

Half of PET bottles collected for recycling come from curbside programs, with most of the remainder collected by bottle deposits.

This profile explores PET packaging.

PET Municipal Solid Waste (MSW) Facts: Generated: * 1.36 million tons or 0.63% by weight.*

* 750,000 tons of soft drink bottles.*

* 480,000 tons of custom bottles.*

* 130,000 tons of non-bottle packaging.*

* 9.1 pounds of PET bottles per person.*

* 10.1 pounds of all PET packaging per person.*

* 9 2-liter soft drink bottles in a pound of PET.

* 80% of bottles are generated in homes and 20% are generated in businesses.*

Recycled: * 372,000 tons for a 24.8% recycling rate in 1998 (industry data).

* 330,000 tons for a 26.8% bottle recycling rate.*

* The PET recycling rate has steadily declined for the last four years.

* 294,000 tons for a 19.6% bottle utilization rate in 1998 (Industry data based on clean flake used for final product and export only).

* Other PET packages and products only are recycled minimally.

Recycled Content: * Rare in bottles, although its use has been approved by the FDA.

Composted: * PET does not compost.

Burned or Landfilled: * 1.03 million tons or 0.66% of discarded MSW by weight.*

* PET is highly combustible, with a per-pound Btu value of 10,933 (compared to 4,500 to 5,000 Btus for a pound of MSW).

Landfill Volume: * 2.76 million cubic yards or 0.7% of landfilled MSW were soft drink bottles in 1997.*

Density: * Landfilled soft drink bottles weigh 355 pounds per cubic yard.*

* Whole PET bottles have a density of 30 to 40 pounds per cubic yard.

* Baled PET bottles have a density of 400 to 500 pounds per cubic yard.

* Granulated PET bottles have a density of 700 to 750 pounds.

Source Reduction: * PET soft drink bottles are 28% lighter than they were 20 years ago.

Recycling Markets: Recycled PET's primary market is the fiber market, which uses recycled PET bottles for carpet, clothing and more. Recycled PET's also can be used for food and beverage containers. Export markets are becoming increasingly important.

Some processors will not take custom bottles because of difficulties in removing food oils from the bottles.

End-Market Specifications: PET bottles fall under Institute of Scrap Recycling Industries (ISRI) Scrap Specifications, Circular '98: Plastic Standard P-100 series. These include specifications for soft drink bottles separated by color or mixed together; mixed soft drink and custom bottles; and mixed bottles with jars, tubs, trays, etc. Contamination is limited to 2%, and PET cannot be stored outdoors for more than six months unless protected.

Polyvinyl chloride (PVC), which has almost the same specific gravity as PET, is a major contaminant. PVC bottles are mixed inadvertently with PET bottles because they look alike or are included in bottle caps with PVC liners. Mechanical or manual systems can be used to separate out PVC.

Recycling Cost and Value: * Bottle collection costs range from $987 per ton to $1,401 per ton.

* Bottle processing costs average $183.84 and range from $64.43 - $295.35.

* No data exists for other PET packages.

American Plastics Council, Washington D.C. Website: www.plastics

"Characterization of Municipal Solid Waste in the United States: 1998 Update," U.S. Environmental Protection Agency (EPA), Office of Solid Waste, Website:

Measurement Standards and Reporting Guidelines, National Recycling Coalition, Alexandria, Va., Website:

National Association of Plastic Container Recyclers, Charlotte, N.C. Website:

National Solid Wastes Management Association,Washington, D.C. Website:

Processing and Collection Cost, Recycling Times, Washington, D.C., Website:

Studies, Waste Recyclers Council, Scrap Specifications Circular 1998, Institute of Scrap Recycling Industries, Washington, D.C., Website: www.isri. org

* 1997 U.S. EPA estimates.