What Is This Garbage?

From "About Plastics," a New York City Department of Sanitation brochure designed to explain the city's recycling program:

Currently, the City recycles PET (Polyethylene Terephalate) and HDPE (High Density Polyethylene) plastics in the form of plastic bottles and jugs ONLY.

Residents are instructed to place all other plastics in the regular trash. PET and HDPE plastics, and all other types of plastic, are usually labeled with a code--recycling arrows with a number inside--on the bottom. This voluntary code, developed by the Society of the Plastics Industry (SPI) and referred to as an SPI code, specifies the type of plastic according to the resin from which it is made.

The City asks residents to separate items for plastic recycling by container type (bottles and jugs) and not by SPI code [1] and [2] because:

  • All HDPE [2] plastics are not the same. Bottles and jugs (containers with the neck smaller than the body) are formed by blow-molding--a bubble of air is blown into the plastic to form its shape. All plastic containers other than bottles and jugs (the neck is larger than the body) are formed by injection-molding--plastic is squirted into a closed mold that is then broken open. Melted injection-molded resin is thin (like water) and melted blow-molded resin is thick (like molasses). If mixed together, the resulting resin is not ideal for either process. Currently, the City does not separate and recycle resin from injection-molded HDPE.
  • Current technology does not enable processors to sort plastics according to SPI codes. Workers would not know which plastics are [1]s and [2]s without picking them up and looking for a code. Inspecting each container as it moves along the conveyor belt would be inefficient and extremely costly.
  • Almost all plastic bottles and jugs are PET [1] or HDPE [2]. However, other kinds of containers are made of various resins; e.g., some ice-cream and yogurt containers may be made of HDPE [2] and some may be made of PP [5].
  • 99% of PET and 86% of HDPE containers are produced in the form of bottles and jugs. Therefore, collecting bottles and jugs yields the vast majority of PET and HDPE containers. Even if processors could sort out and recycle all other PET and HDPE containers, asking residents to set out all [1]s and [2]s would not result in the collection of significantly more material.
  • The SPI coding system is voluntary; not all PET and HDPE is labeled.
  • Significant quantities of non-container HDPE plastic is sold in the U.S. in the form of film plastic (e.g., grocery bags). Bags labeled as HDPE or coded [2] would mistakenly end up in recycling containers; they are not recycled and would be a contaminant.
  • It is easier to understand and follow instructions to recycle plastic bottles and jugs than it would be to inspect every type of plastic to find the code.

All [1]s and [2]s that are not bottles and jugs are considered residue and end up in the landfill. THE DEPARTMENT OF SANITATION COLLECTS ONLY PLASTIC BOTTLES AND JUGS FOR RECYCLING.

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