What Do the Numbers Inside Recycling Symbols on Plastic Items Mean?

bottom of pill bottle
The bottom of this pill bottle shows that it is made of No. 5 plastic, which means it is made of polypropylene and usually can be recycled. Marilyn Root/Getty Images

Plastics aren't so great for the environment or our health. Unfortunately, a lot of consumer goods are enclosed in the stuff. On the plus side, many plastics are recyclable, which is helpful because plastics can take up to 1,000 years to decompose in a landfill.

To help you figure out whether or not you've got a recyclable item, most plastics contain a recycling symbol, often placed at the bottom of the item. The symbol is a triangle formed from arrows. And, as there are seven categories of plastics, a number from one to seven is set inside the triangle to tell you which kind of plastic you've got. Here are the seven categories [source: Seaman]:


  • 1 - Polyethylene terephthalate (PETE)
  • 2 - High-density polyethylene (HDPE)
  • 3 - Polyvinyl chloride (PVC)
  • 4 - Low-density polyethylene (LDPE)
  • 5 - Polypropylene (PP)
  • 6 - Polystyrene (PS)
  • 7 - Other

No. 1 plastics (PETE) are used for items such as plastic soda bottles and cooking oil containers. It's the most common type of plastic and meant for single use, rather than reuse. No. 2 plastics (HDPE) typically contain liquids such as milk, cleaning fluids, laundry detergent and shampoo. PVC, or No. 3, is the base for any form of vinyl, from siding to seat covers. It's also used to make trays that hold fruit and sweets, and is found in food foils.

Plastic shopping bags and cling wraps are made from low-density polythene (LDPE) or No. 4. Polypropylene (PP or No. 5) is used in furniture, luggage, pill bottles, toys and plastic linings for diapers, cereal and yogurt cups. Polystyrene (PS, No. 6) is also used in toys, as well as in Styrofoam cups, takeout containers and hard packing. No. 7 is a catch-all category for all other plastics, such as acrylic, nylon, baby bottles and fiberglass.

There are several key things to know about recycling and these categories. First, No. 7 plastics -- the ones in the "Other" category -- are a mix of recyclable and nonrecyclable products. Unless you're a plastics expert, you won't be able to tell the difference, so it's best to avoid recycling these products [source: Anderson].

Second, you can only recycle clean plastic, meaning you must wash items before tossing them in your recycling bin. Third, even if you have an item that is clean and recyclable, it won't necessarily be recycled. Municipalities often set local recycling regulations, so check your city website to see which plastics are accepted. Some plastics that are not accepted for curbside pickup may be accepted at special recycling sites.

Finally, if a product doesn't have a recycling symbol, toss it in the trash. It's better to keep a potential contaminant out of the recycling stream than take a chance.


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More Great Links

  • Barrett, Mike. "The Numbers on Plastic Bottles: What do Plastic Recycling Symbols Mean?" Natural Society. Feb. 6, 2013. (Jan. 30, 2019) http://naturalsociety.com/recycling-symbols-numbers-plastic-bottles-meaning/
  • LeBlanc, Rick. "The Decomposition of Waste in Landfills: A Story of Time and Materials." The Balance Small Business. Dec. 16, 2018. (Jan. 30, 2019) https://www.thebalancesmb.com/how-long-does-it-take-garbage-to-decompose-2878033
  • Ryan, Sheryl. "Which Plastics Can or Cannot Go In The Recycle Bin? Here's Your Quick List." Greenopedia. (Jan. 30, 2019) https://greenopedia.com/plastic-recycling-codes/
  • Seaman, Greg. "Plastics by the Numbers." EarthEasy. May 2, 2012. (Jan. 30, 2019) https://learn.eartheasy.com/articles/plastics-by-the-numbers/
  • Sedaghat, Lillygol. "7 Things You Didn't Know About Plastic (and Recycling). National Geographic. April 4, 2018. (Jan. 30, 2019) https://blog.nationalgeographic.org/2018/04/04/7-things-you-didnt-know-about-plastic-and-recycling/