The Significance of Numbers on Plastic Recycling

If your community has a plastics recycling program, usually only certain types of plastics are accepted. How do you know which plastics qualify? The answer can be as simple as turning a bottle upside down.

Look Out for Number 1 (or 2 or 3)

• In 1988, The Society of the Plastics Industries, Inc. (SPI) introduced a method of categorizing plastics called a resin identification coding system. Simply put, the number you see on the bottom of a plastic container indicates the type of plastic.

SPI Resin Identification Codes

• These nationally recognized codes help facilitate the recycling process:

  1 = PET (Polyethylene terephthalate)
  2 = HDPE (High-density polyethylene)
  3 = Vinyl
  4 = LDPE (Low-density polyethylene)
  5 = PP (Polypropylene)
  6 = PS (Polystyrene)
  7 = Other

Know Your Numbers

• Type 2 plastics are easy to identify.

  It should not take you long to remember that a milk jug always goes into the "Type 2" recycling bin, and that most soda bottles are stamped with a "1."

Ask First

• Just because that plastic take-out container has a number stamp does not necessarily mean you can throw it in the recycling bin. Ask your local recycling center or organization for a list of plastic types they will collect.

Missing Numbers

• Not all plastics have numbers stamped on them. According to The Society of the Plastics Industry, as of January 2010 only 39 states have laws stipulating the use of SPI codes on "bottles and rigid containers."