Profiles in Garbage: High-Density Polyethylene

Generated: * 1.48 million tons or 0.68% of total MSW by weight.*

* Milk bottles provide 670,000 tons or 45% of HDPE packaging by weight.*

* 10.96 pounds per person in 1997.

Recycled: * 360,000 tons for a 24.3% recycling rate.*

* 210,000 tons of milk bottles for a 31.3% recycling rate.

* 392,500 tons for a 27.8% bottle recycling rate in 1999.

Recycled Content: * Some nonfood HDPE containers include limited amounts of recycled HDPE.

Composted: * HDPE does not compost.

Incinerated or Landfilled: * 1.12 million tons or 0.71% of discarded MSW by weight.*

* HDPE is highly combustible. There are 18,690 Btus in a pound of HDPE compared to 4,500 Btus to 5,000 Btus for a pound of MSW. This high Btu rate causes problems for boilers with low per-pound Btu ratings.

* HDPE is not landfill biodegradable.

Landfill Volume: * 6.3 million cubic yards or 1.5% of landfilled MSW.*

Density: * Landfilled milk jugs have a density of 355 pounds per cubic yard.*

* Loose milk jugs have a density of 24 pounds per cubic yard.

* Flattened milk jugs have a density of 65 pounds per cubic yard.

* Loose, colored HDPE bottles have a density of 45 pounds per cubic yard.

* Bales of HDPE generally weigh 500 to 800 pounds.

Source Reduction: * In the early '70s, an empty one-gallon milk jug decreased in weight from 95 grams to less than 60 grams.

* One thousand gallons of fruit juice can be packaged in 213 pounds of HDPE containers. This is less weight than that of competing package types (including other plastics).

Recycling Markets: The packaging industry, which uses post-consumer recycled HDPE for bottles, is the largest HDPE recycling market. Drainage pipe, film, pallets and plastic lumber are other uses. HDPE also is exported, usually in bales with other plastics, to Pacific Rim processors. Markets for clear (translucent) HDPE milk bottles are the highest priced markets for HDPE bottles.

End-Market Specifications: HDPE bottles fall under Institute of Scrap Recycling Industries (ISRI) Baled Recycled Plastic Standard P-200 (HDPE Mixed), P-201 (HDPE Natural) or P-202 (HDPE Pigmented). These specifications allow for 2 percent total contamination, no free flowing liquid and less than one month outdoor storage unless covered with UV protective materials.

However, HDPE containers are not covered by any ISRI specifications. These injection-molded containers can be incompatible with blow-molded bottles in reprocessing operations because the two packaging types have different melt flow indexes.

Plastic processors take baled HDPE and separate the bottle components, i.e., caps, labels and their adhesives. Then, they are washed, dried and ground into HDPE flakes. Some processors produce pellets from the flakes.

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

* Processing costs range from $121.58 to $256.15 per ton.

American Plastics Council, Washington, D.C., Website: www. ameriplas. org or

"Characterization of Municipal Solid Waste in the United States: 1998 Update," U.S. Environmental Protection Agency (EPA), Office of Solid Waste, 1999, Washington, D.C. Website:

"Design for Recycling, A Plastic Bottle Recyclers Perspective," Society of Plastics Industries, February 1992. Modern Plastics, New York, February 2000, Website: National Recycling Coalition, Measurement Standards and Reporting Guidelines, Website: www.

"Scrap Specifications Circular 1998, "Institute of Scrap Recycling Industries, Washington, D.C., Website:

Waste Recyclers Council of the National Solid Wastes Management Association, Washington, D.C. Website: /nswma

*1997 U.S. EPA estimates.