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  • Writer's pictureThe Pink Elephant Lady

Landfilled! Part II: Clamshells, Blister Packs, and Other Thermoforms

You may recall that last year, we wrote about how clamshells used to package berries, salad greens, and grab-and-go wrap sandwiches, are often landfilled even though they have the 'chasing arrows' symbol with a 1 inside, and even when they're clean, dry, and put in curbside bins. We have updated information to share with you about this type of packaging and what's happening to it. Read on! (For more background on why thermoforms like clamshells are different from blow molded plastic like water bottles and what that means for recyclability, find our first article here:

There's actually some good news about thermoform recycling: According to a 2020 report from NAPCOR (National Association for PET Container Resources), 2019 saw a 50% increase in recycling of thermoforms compared to 2017. And that's an increase in ACTUAL recycling by processing facilities ('reclaimers'), not just an increase in the amount of thermoforms put in bins. Not ALL thermoforms are landfilled. According to that same report, most reclaimers that buy plastic from curbside bins will allow at least some percentage of thermoforms in what they purchase, usually ranging from 2% to 10%. However, thermoform content in excess of 10% may be landfilled or burned.


Thermoforms are theoretically recyclable, but that doesn't mean they actually WILL be recycled. And with more and more massive multinational companies making public commitments to improve recycling and recycled content, the demand for R-PET (recycled PET, or Recycled Polyethylene Tetrapthalate), is only going to go up. So what can consumers, retailers, product manufacturers, drop-off centers, waste management companies, municipalities, and reclaimers do to ensure that thermoforms get recycled? To answer that question, let's first identify the recycling challenges that thermoforms present.


Reason 1: Look-Alikes

Not all thermoforms are made of PET - and clear PET is the most valuable, highly desired plastic in curbside bins. It's impossible to tell with the naked eye that a clamshell is actually made of compostable bioplastic like PLA (polylactic acid, which is in the catchall 'other' category #7), oriented polystyrene (#6), polypropylene (#5), or some other material and not #1 PET.

All of these containers are thermoformed, but they're #6 polystyrene, not #1 PET. Confusing!

When MRFs (materials recovery facilities) and drop off centers don't have advanced optical sorting equipment but are instead sorting materials manually, it can be near impossible to sort out look-alikes. According to the NAPCOR report, recycling loads sorted with advanced optical sorting machines result in less than 1% contamination. Buyers of reclaimed plastic don't want contaminated loads. They want loads that are composed of the material they want to buy. And what they want to buy most is #1 PET.

We've been saying all along that both access to curbside recycling and the likelihood what's put in those curbside bins actually gets recycled is, like so many things, largely a factor of how wealthy a city is. A wealthy city might have access to advanced optical sorting equipment. A poor city probably doesn't.

If you'd like a short primer on various types of plastics used in the consumer products and retail food industries, go HERE.

Reason 2: Labels

Labels and the adhesives used to attach them can be the bane of the recycling industry. Labels, however, are absolutely mandatory because they indicate the product's ingredients, allergen information, nutrition facts, and the name and address of the company that made the product. This information is REQUIRED by law to be on the container (see FDA requirements for food labels and for cosmetics/personal care labels). Unfortunately, certain types of labeling can be nearly impossible to remove and can send a clean, dry, otherwise highly recyclable container to the landfill.

Supplements, food, drugs, cosmetics, and other products are required by law to have labels. It's not optional.

The Association of Plastic Recyclers has developed Design for Recyclability Guidelines to help packaging designers and product companies ensure that both containers AND their labeling are suitable for wide-scale recycling. I won't go into too much detail here about labels, but the guidelines do get very granular about what makes a label or adhesive acceptable for recycling, questionable for recycling, and 100% unrecyclable. For example, adhesives that easily wash-away remove cleanly during the recycling process and allow for collection of the newly separated label material. The PET sinks to the bottom of the float tank as the label materials float to the top to be easily skimmed off and potentially recycled themselves.

Reason 3: Other Technical Stuff

Other technical concerns that can pose a challenge to recycling thermoforms are the great variety of sizes and shapes of thermoforms, and two other factors you may have never heard of: intrinsic viscosity (IV) and fines.

Recycling was originally designed to handle materials of a predictable size and shape: water bottles, metal cans, sheets of cardboard. However, product manufacturers have come up with all sorts of new materials, sizes, and shapes that are not designed with recycling as a priority. These lighter, oddly shaped materials are difficult to sort out in materials recovery facilities, as older sorting equipment isn't designed to handle it. Newer, better, expensive robotic optical sorting equipment can do the job, but many if not most facilities don't have that type of equipment.

IV is a characteristic of plastic flake. Plastic 'flake' is the final product of the plastics recycling process, and this is what plastic reclaimers sell to manufacturers that make bottles, clamshells, jars, etc. out of recovered plastic. The waste hauler collects the bottles curbside, they get dropped off at the city's MRF (materials recovery facility), the MRF bales the bottles and sells them to a plastics reclaimer, the plastic reclaimer turns the baled bottles into flakes, and finally, the manufacturer buys the flake and makes new containers, textiles, or some other end product.

This is recycled plastic flake, which gets turned into new products.

Intrinsic Viscosity is a measurement that tells plastics manufacturers something about the strength of plastic flake. The IV that a plastics manufacturer requires depends on what they're trying to make with the plastic. Thermoforms make a plastic flake with a lower IV than plastic flake from blow molded bottles.

'Fines' are pieces of material that are of a significantly smaller size than the rest of the sample. The presence of excessive fines can complicate the recycling process. The recycling of thermoforms results in a higher incidence of these fines than recycling blow molded bottles.


As you can see from this article, there are many factors and many parties involved in the purchasing, recycling, and production of plastics in general, and thermoforms in particular. Who gets the blame when they get thrown out instead of recycled?

Is it the plastics manufacturer that created the thermoformed clamshell? The deli that purchased the clamshells for their sandwiches? The drop-off center that tells you they take plastics #1-#7, but doesn't know that 90% of the thermoforms dropped off or collected curbside are getting landfilled? The company that made the label but had no idea that some labels make otherwise recyclable containers go to landfill? The grocery store shopper that buys strawberries and washed arugula in clamshells? Waste Management and Advanced Recycling that pick up your curbside recycling but then landfill the thermoforms set aside by the MRF because there's too many of them in the load and the buyer doesn't want them?

To throw our hands in the air and say "Everyone is lying" isn't entirely accurate. The truth is complicated, and every party to this entire process deserves a certain amount of blame. The waste hauler and the municipality aren't necessarily deliberately trying to deceive anyone. When it comes to 'the truth' about recycling and why some things get landfilled, is it realistic to think that the average resident really wants to hear about the differences between blow-molded versus thermoformed plastics?


  • Every company that makes stuff, from Unilever and PepsiCo to the new raw juice shop in your neighborhood, should follow the APR 'Design for Recyclability Guidelines' when deciding what to package their product in and how to label it.

  • Every federal, state, and local government should be working towards creating facilities with advanced optical sorting equipment to improve the amount of curbside bin materials that actually get recycled.

  • Every brand owner, from the body butter/body oil people that pop up at farmer's markets and vendor shows to the cupcake and popcorn brand owners should learn about what affects the recyclability of their product's container BEFORE they start selling it.

  • Companies that profit off selling products in unrecyclable containers, regardless of the reason the container is unrecyclable, should be funding recycling infrastructure for poorer cities that can't afford it.

  • Every consumer should be holding brands accountable for their commitments to recycling and extended producer responsibility.

  • Everyone who cares about recycling and reducing and reusing should realize that a tiny percentage of people doing extreme zero waste while the rest of the country doesn't do much at all is NOT SUSTAINABLE. We should focus on making achievable, measurable changes, not making ourselves feel better by engaging in virtue-signaling, purism, holier-than-thou-ism, and alienating others.

  • Let's change how we approach people around us. You're vegan? Great! Most people aren't and will never be. Let's show people how to go meatless one day a week or how to reduce meat consumption to only one meal a day.

'Eeeww' across social media, except on zero waste blogs. How much 'change' does this really inspire?

Your waste fit into a single jar from an entire year? That's awesome! But that seems so inaccessible and unapproachable that it turns most people off. People that aren't like you and never will be make waste, eat, go shopping, and wash clothes WITHOUT homemade laundry soap and a clothesline outside. Let's try to focus on those millions of people and pounds of trash by improving access to curbside recycling and composting infrastructure and education. That will create change for far more people in far more places than obsessing about the stickers on bananas.

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