Have you ever looked at a plastic container and wondered, what does the number on the bottom of the packaging mean?

Our neighborhood waste disposal company provides a curbside recycling program. Until recently, the company restricted the numbers of the plastics that could be recycled.

This got us wondering, does everyone actually know what those numbers mean?

The short answer is that the number indicates the type of plastic used in producing the container.

The long answer is that this number is the “resin identification code.” It was developed by The Society of the Plastics Industry (SPI) in 1988 to assist recyclers around the country. This code provides a mechanism for recycling companies to sort the materials that they receive. The numbers in the code are defined as follows:

1 – Polyethylene Terephthalate (PET or PETE). This is a clear plastic that is commonly used in drink bottles. Recycled PET can be found in tote bags, clothing, carpet, etc.

2 – High Density Polyethylene (HDPE). This is a more durable plastic that is typically found in milk jugs, juice bottles, and chemical containers. Recycled HDPE can be found in similar containers as its original use as well as other products. For example: furniture, recycle bins, and trash cans).

3 – Vinyl (Polyvinyl Chloride or PVC). This material offers excellent chemical resistant properties. PVC is used for piping among other household and industrial products.

4 – Low Density Polyethylene (LDPE). This material is very strong and flexible. Squeezable bottles for consumer products are usually made of LDPE. Recycled material can be used to create compost bins, floor tiles, furniture, and many others.

5 – Polypropylene (PP). Found in consumer product containers (i.e. yogurt and butter containers) and automotive parts, polypropylene can be rigid or flexible. This material is usually recycled into medium to large molded parts.

6 – Polystyrene (PS). This material is typically found in egg cartons, cups, plates, and packaging equipment. Polystyrene comes in a few forms, including rigid, foamed, and brittle textures.

7 – Other. Plastics bearing the “Other” code may be produced from a material not listed under the other codes or may have a mixture of materials. Depending on the types of plastics involved in the production process, the final product may be categorized as 7, or “Other.” Recycled number 7 type plastics are typically found in recycled plastic or composite lumber products.

In future postings we will look at companies and products that use these recycled materials to make great new products!