Curt Harler


Beyond the numbers


New nomenclature seeks to clear up consumer confusion surrounding plastics recycling.

October 1, 2014

A rose is a rose is a rose. But a bale of Nos. 3 through 7 plastics is probably not a bale of Nos. 3 through 7 plastics, and encouraging residents to include Nos. 1 through 7 plastics in their recycling bins doesn’t translate to many participating residents. This is a problem for those at every level of the recycling industry.

Buyers are unclear about exactly what they are buying. Consumers, the first line in the recycling chain, are vexed by the multiplicity of numbers and the definitions.

However, help is on the way. New nomenclature aims to clear up the confusion, making it easier for consumers to understand which plastics they should put in their recycling carts and for MRFs (material recovery facilities) and PRFs (plastics recovery facilities) to give their customers a clean, segregated product at the other end of the supply chain.

At the heart of the proposal is a new series of outreach terms (a glossary or lexicon) and royalty-free images to help communities communicate more effectively to residents which plastics to recycle, making it easier for residents to participate and to recycle more of these desired materials. In addition, a set of standard plastic commodity terms has been developed for the whole recycling value chain to communicate what is being diverted through recycling programs and to facilitate better data tracking at the organization, local, state and national level.

The proposal embodies the KISS rule: Keep It Simple, Sir! It has the support of the Association of Postconsumer Plastic Recyclers and many other groups.

Problems all around

The plastics recycling rate is stuck around 30 percent, and many in the industry maintain that, unlike glass or even paper, people simply will not or cannot sort out the different kinds of plastics.

“People are so confused on the terminology,” says Patty Moore, principal of Moore Recycling Associates Inc., Sonoma, California. “Plastics are the most common recyclable material people ask about.”

Moore studies the plastics recycling sector, including the place PRFs have in the processing chain. Her research shows that most ordinary people, and also some in the industry, do not understand the numbers commonly used on plastic packaging.

Plastic #1 – #7

Plastics Bottles & Containers

Use more description terms your residents can relate to:

Plastic Bottles & Containers

  • Plastic Soda, Water and Other Drink Bottles
  • Plastic Food and Household Bottles/Jars
  • Plastic Tubs & Lids
  • Plastic Produce, Deli & Bakery Containers, Cups, Trays
  • Plastic Non-food Containers & Packaging

Plastic Buckets

*Empty, flatten and put caps back on bottles/jars

*Rinse or wipe clean all food or other residue from bottles

No Containers that held Hazardous Products

She prefers the generic term “nonbottle rigid plastics” rather than referring to this category as Nos. 3 through 7, since she maintains the numbering system is confusing to consumers and mostly meaningless.

She says she also hopes the industry will adopt the bale category “prepicked rigid plastic,” saying, “I have yet to see a No. 3 through No. 7 bale that has only No. 3 through No. 7 in it. They all have PET (polyethylene terephthalate) and HDPE (high-density polyethylene) in them.”

One of the challenges to getting a segregated mix of Nos. 3 through 7 plastics is that many yards do a negative sort on plastic beyond PET and HDPE bottles. Foreign materials—whether chunks of wood or pieces of metal—get into the load.

Moore worked with the American Chemistry Council and the Association of Postconsumer Plastic Recyclers on a series of studies aimed at developing standards for recovered plastics. The hope is that new bale standards and terms, coupled with the new standardized terms for public education and outreach, will improve the amount and quality of plastic recycled. The new system also is designed to make it easier on the back end to track which plastic materials are actually being recycled.

“If we all use the same terms, we can do business,” Moore says.

Collecting nonbottle rigid plastic

For the most part, the project provides simple descriptive terms (See the table on the right), while visual cues are provided through the use of royalty-free images. All the terminology and images can be found at

“To have success in recycling nonbottle rigid plastics, you need a clear definition of recycling guidelines,” Moore says.

The new lexicon is already in place on ReTRAC Connect waste diversion software. This terminology matches the new outreach terms for plastic recyclables.

Resin codes will not change; they simply will not be so prominent, especially at the consumer level.

A touch of history

The original curbside collection programs that blossomed in the 1990s focused on PET and HDPE. The numbering system worked well for the typical MRF; however, for ordinary people, it was a pain.

“People got tired of reading the bottom of their bottles,” says Arthur Boone, owner of the Center for Recycling Research, Berkeley, California. Eventually, municipalities told citizens to include anything with a screw top. The idea was to collect more No. 1 and No. 2 plastics and throw away the containers numbered 3 through 7.

Market basics have not changed. No. 1 (PET) and No. 2 (HDPE) bottles are most commonly recycled. The situation is different for Nos. 3 through 7 plastics. PVC (polyvinyl chloride, No. 3) is commonly used in liquid food bottles and cable covers and considered the most problematic of plastics to recycle because of its chlorine content. LDPE (low-density polyethylene, No. 4) is used in case wrap, bread bags and pallet wrap; it typically is collected at retail drop-off locations and at the back end of businesses and recycled into garbage bags and other products. Polypropylene (PP, No. 5) is the fastest growing recycled resin. Polystyrene (PS, No. 6) is found in cups and takeout containers. And No. 7 is the catch-all “other” class that includes multilayer plastics.

As more of this wider range of plastics was collected, buyers for Asian companies saw the chance to buy these mixed plastics relatively cheaply; the cost of shipping a container from the U.S. to China is relatively low. China also had a cheaper source of labor to perform sorting and the need for raw material. It was a win-win.

That is, it was a win-win until the Chinese government cracked down on contaminated mixed loads of recyclables coming into the country. China initiated Operation Green Fence, inspecting loads for quality and proper segregation of materials. The country’s officials had no problem with recycled plastics, they simply wanted well-segregated, cleaner loads of recyclables.

Using the plastics

In the meantime, the nonbottle rigid plastic supply has been growing, and more communities are collecting the material.

Demand for PET bottles far outpaces supply, Moore says. Little chemical reason exists as to why recycled PET thermoforms cannot be used to augment recovered PET in most applications. The optical signature for PET thermoforms and for water bottles is similar, so they are a simple matter for sorters to deal with. Although other issues, specifically problems with labels and glues (some inks bleed, and some glues come off and redeposit on the material) cause significant problems in the reclamation process.

APR’s Design for Recyclability guidelines aim to minimize these and other design problems.

For areas of the country where sufficient supply or an established market are not available to use all of the recycled nonbottle rigid plastic materials collected, a plastics-to-oil operation could make a good addition to a PRF, Moore says.

“My research has shown that plastics-to-oil will not work (economically) as a stand-alone,” Moore says. “As an addition to a mechanical sort line, it has a chance. It is cheaper than landfilling and has a good use,” she adds.

Moving ahead

“People are excited about this concept,” Moore says of the change in nomenclature, noting that citizen groups, state recycling coordinators, operators of MRFs and PRFs and purchasers of recycled plastic all stand to benefit.

Again, it is important to note that the resin identification codes will not change or disappear. This is important for several reasons, not the least of which is the simple fact that some 39 states require the Nos. 1 through 7 resin codes to be imprinted on all plastic containers.

However, Average Joe can quickly distinguish between a water bottle and a deli container rather than between a No. 1 and a No. 5 plastic.


The author is a contributing editor to Recycling Today based in the Cleveland area. He can be contacted at


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