Have you ever seen numbers on plastics and wondered what they mean?  There are hundreds of different types of plastics, with different properties, making them more flexible or ridged.

The numbers 1-7 on plastics indicate what type of plastic is used in your bottle, container, or shopping bag. Here’s a quick guide to knowing what these numbers really mean.

  1. Plastics labeled with a 1 are  PETE and are typically found in food or beverage bottles and are easily recyclable. PETE is most common for single-use items.
  2. Number 2 plastic is HDPE, which is used in clean product bottles. It is considered a safe plastic, because it doesn’t break down easily and is easily recycled.
  3. Number 3 is for PVC, which is commonly used in piping and other building materials. When burned, PVC releases toxic gases into the environment and is harder to recycle because of this toxicity.
  4. Plastic bags are commonly made from LDPE, number 4, and can be recycled in bulk. You can return shopping bags to your grocery store to recycle them, but never put individual plastic shopping bags into the recycling bin.
  5. Number 5 plastic is found in straws and squeeze bottles. Some of these products can be recycled, but straws are not recyclable.
  6. Styrofoam is made from PS plastic with the number 6. Evidence has shown that these plastics leak toxins into their environment relatively easily and take millennia to degrade naturally. Number 6 plastics can be recycled if collected properly. At Tufts, the Science and Technology Center collects styrofoam in bulk for specialty recycling.
  7. The last category, number 7, is miscellaneous plastics. The attributes and recyclability of the plastics are variable.

To learn more about how recycling works watch this great video from Sci Show:

Be sure to check the numbers on the bottom of your plastics and refer to this guide to recycle your plastics correctly. Recycling is a great way to reduce our environmental footprint and a big step toward making our world more sustainable, but remember that reducing use and reusing items should always come before recycling.