Have you ever noticed the number inside the recycling symbol on bottles or other plastic recyclables? Do you know what these recycling numbers mean? At the bottom of almost any plastic container, inside the recycling symbol is a small number between 1 and 7. Each number refers to the type of plastic the container is made of, and therefore what kinds of plastic materials the container can be recycled with.
Plastics are all composed of different molecules or molecular structures. Just as glass, paper, and plastic cannot be recycled together, different molecular structures cannot be recycled together which means each type of plastic must be recycled with similar types of plastics. The numbers added to plastic containers are a way of classifying the different types of plastics in order to help sorting efforts at a recycling plant. In addition to having a number, some plastics also have letters next to the recycling symbol. These letters generally refer to the material the plastic is composed of, like: PETE – Polyethylene terephthalate, HDPE – High-density Polyethylene, V – Polyvinyl chloride, LDPE – Low-density Polyethylene, PP – Polypropylene, and PS – Polystyrene.
The most common recycling code numbers are 1 and 2, and most plastics fall into one of these categories. A number 1 is generally found on soda bottles, disposable water bottles, and cooking oil. Number 2 can be found on milk cartons, shampoo bottles, and laundry and dish soap. Recycling number 3 is seen on medical tubing, seat covers, shower curtains, and vinyl dashboards. Number 4 consists of sandwich bags, wrapping films, and grocery bags, though it should be noted many cities will not accept grocery bags as they clog machines. Recycling number 5 consists of stronger plastics like tupperware, yogurt and sour cream tubs, and plastic soda bottle caps. Number 6 is found on plastic cups, disposable silverware, and some packing peanuts and styrofoam, though like plastic bags, many cities will not accept these. Lastly, recycling number 7 is plastics made from combinations of 1-6, or less common plastics.
Recycling numbers, often referred to as recycling codes, were developed in 1988 by the Society of the Plastics Industry, who along with the Federal Trade Commission, developed the following guidelines in regards to recycling codes:
- Identifies the type of plastic only
- Should not influence consumer decision making, must be as inconspicuous as possible
- Cannot be modified in any way
- To be used on bottles and rigid containers
- Must appear on the bottom of a container as close to the center as is possible
- Imprinted on all containers, 8oz to 5 gal that can accept the minimum size symbol
- Make no claims of recyclability
Need testing for recycled products or other plastics testing?
We can help! Visit our website to submit a request, or call us 1-855-377-6821 for assistance with your plastic or recylables testing! Some of the test requests we have helped other organizations find laboratories for include:
- Materials laboratory needed for classification testing of recycled in order to determine who can buy it from us.
- physical laboratory needed for plastic cable testing such as Load rating for pedestrian and vehicle (H-20, 40) for cable made of recycled plastic.
- Large corporation needs microbiology laboratory to determine presence/absence of bloodborne pathogens on recycled paper towels
- Manufacturer a counter top material with recycled window glass and an epoxy resin binder needs physical laboratory for testing such as: NSF / ANSI / ASTM Physical Properties Testing Food Safety:NSF/ANSI 51 compressive strength, tested to ASTM C39 Absorption, tested to ASTM c-97-02 Sctratch Resistance/Mohs Hardness Modulus of Rupture, tested to ASTM c-99 Radon Emissions, compared to EPA-402-r-92-004 PH Miscibility(in water) Density Bending Stress Coefficient of thermal expansion Autoignition Temperature Fire point
- Laboratory needed for anion testing for determination of anions in recycled NMP, N-Methyl-2-Pyrrolidone,
- and many more!
To learn more about how we can help with your plastics testing, click here.