What Plastics Cannot Be Recycled? (Full Guide)

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Jean Richardson

Jean Richardson is a lover of knowledge, in all forms. He has spent over 15 years as a high school teacher, instructing students in history, geography, mathematics, and more.

Nowadays, we all want to do our part to make this world a better place than we found it, and to leave it as such. From saving the ocean to recycling, everyone wants to make sure they do things that might seem easy but can also have a profound impact on the environment.

Therefore, continue reading to learn how we can do this by properly recycling and disposing of the trash we create! 

What Plastics Cannot Be Recycled?

As much as we’d like to recycle as much plastic as possible, the fact is not every plastic can be recycled?. Even those with certain recycling triangles will have restrictions on if they can be recycled or not. Typically, the lower the number on the triangles are safe bets that you can put in your regular recycling bin.

Now that there are stipulations on plastics and what can and can’t be recycled, you’re probably wondering how to decide what goes in which bin, if something has to be taken to a special facility, or if it simply has to go in the trash. Continue reading to find out these answers!

Why Can’t You Recycle All Plastics?

Growing up, we all got used to seeing the arrows that formed the recycling triangle to let us know to throw that item in the recycling bin. 

The problem now is, even when a bottle or certain plastic has that triangle, that doesn’t necessarily mean it can be recycled, and sometimes it actually shouldn’t be recycled.

It’s great that people want to do their part and recycle because they think it’s helping, but they need to know what to recycle, and what to throw in the garbage.

Although we tend to think plastic is plastic, not all plastics are created equal.

Ins And Outs Of Plastics And Proper Recycling

It’s important to note where the market and your local government stand on recycling because they are both strong variables on if your recycling efforts are actually productive or not. 

The Market

The market determines many of our actions because money is the loudest speaker and most heard by many decision-makers.

Therefore, if the recyclables are too worn or dirty, or there’s simply no money to be made, then they’re going back to the landfill. 

Furthermore, it has to make sense and be in line with what the market is saying for those in charge to want to spend the time and money on recycling.

Local Government

Your local government also needs incentives to ensure they purchase the proper equipment to break things down, but that’s going to come out of the budget and taxpayer dollars.

If there are mandates or if they see issues without recycling and see a solution with it, then it is much more likely that your local government will be more in tune with the need for recycling.

In essence, some of the stipulations behind recycling and what is and is not possible are unfortunately not in the hands of the citizens, 

This makes their efforts to dispose of waste properly just a little bit harder.

The 7 Types Of Plastics

Back to our recycling triangles. We look at those and automatically think, “Oh perfect, this can go in the recycling bin.” 

However, that’s not always the case. Those are referred to as the plastic resin codes, and there are 7 different types:

  1. Polyethylene Terephthalate (PET) – this often refers to drinking bottles and cups.
  2. High-Density Polyethylene (HDPE) – HDPE includes bottles, cups, and milk jugs.
  3. Polyvinyl Chloride (PVC) – this commonly contains rigid plastics like pipes and tubes.
  4. Low-Density Polyethylene (LDPE) – these are different types of plastic-like 6-pack fasteners and plastic bags.
  5. Polypropylene (PP) – is used in food containers and even some plastic car parts.
  6. Polystyrene (PS) – is also used to hold food, drink cups, and plastic utensils.
  7. ‘Other’ – a more general category for acrylic, nylon, and other obscure plastics

An easy, and mostly correct, rule of thumb to follow is that the lower the number, the more likely it is ok going into the recycling bin. 

The RIC codes for 1, 2, and 3 are the most common that we see regularly, making them easy to dispose of when they’re taken to the recycling facility. 

Once you get to 4 and beyond, though, those plastics are not as easy to break down and you will have to do a little research on how to dispose of them properly.

Therefore, recycling triangles are a great resource for people to identify what type of plastic it is and how easily it can be disposed of. 

Unfortunately, they don’t all mean the same thing and can’t all go into your everyday recycling bin.

However, they are a good guide to help you figure out what to do with the more difficult plastics.

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Breaking Down Plastics Even Further

Within those 7 types of resin codes, plastics can also be separated into 2 categories: thermoplastics and thermoset plastics.


For the majority of the discussion, we have referred to plastics that can be heated, melted, and broken down completely to be used again in other plastic materials. 

Furthermore, these plastics are known as thermoplastics. 

Thermoplastics are made of materials that have a certain chemical composition that allows things to be converted into new substances to be used at a later date. 

These are the plastics that you will see being recycled more commonly than the higher coded resin plastics. 

Thermoset Plastics

On the other hand, thermoset plastics cannot be heated and broken down due to their chemical makeup, and thus are unable to be recycled in any form no matter how much they are heated.

For example, coffee cups and snack bar wrappers are considered thermoset plastics. 

Ironically, coffee shops will have a trash and recycle bin for you to throw your cup when you are done, but it’s not quite that simple. 

Coffee cups tend to be made up of multiple materials, and one of them has plastic on the inside lining.

So unless someone found a way to separate the two types of chemicals, throwing the coffee cup in the recycling bin is counterproductive.

It might even cause the whole batch of recyclables that the facility receives from that store to be contaminated. 

As you can imagine, making products like this, especially when bought in bulk, can be extremely cost-effective for any business. 

Furthermore, chances are that the products used to make that coffee cup were at the end of their life cycle in terms of being reused, aiding in the lower price of the cups. 

Can I Mix Different Plastics In Recycling?

In general, it’s a good idea to try to separate your plastics the best you can, but this is also where some research on your recycling facility may be warranted. 

As it’s important to know whether they can separate all the plastics that come in, otherwise they might send the entire load to a landfill. 

Furthermore, what could get confusing is when two different types of recyclables end up having the same type of resin (that type of chemical) code. 

For example, if you have a tub or plastic container of some kind, then a glass bottle each with the same triangle and code, one would think to put those in the same recycling bin. 

Unfortunately, glass and plastic tubs shouldn’t be mixed together. 

Since they are two different chemicals, they will break down differently and should not be broken down together in the same machinery.

It would be nice if we could just mix all the recycling triangles, but with a little extra research, it’s understandable why not all plastics should be mixed and broken down together. I

Does The Plastic Have To be Clean?

Does The Plastic Have To be Clean?

Leftover containers have a little residue on them? But it doesn’t matter if there are a few residuals left because it can still be recycled, right?

You actually cannot recycle dirty plastic. For plastics to be broken down and transformed into recycled goods properly, they must be clean. 

If not, they will be rendered “useless” and thus have to be sent to the landfill.

Therefore, the best way to go about your plastics is to give them a good rinse after you are done with them.

Your recycled materials are going to be paired with materials that haven’t been used before, and therefore must meet certain standards in order to be broken down and reused. 

It sounds silly cleaning plastic, but if they’re going to be converted into other materials for use again later, they must be as close to pure as possible. 

The Beauty Of Metal And Glass

There are a few materials that have a lot fewer restrictions than plastic, especially when it comes to reducing, reusing, and recycling them. 

In this case, metal and glass make for the easiest and safest conversions back into safely recycled materials.

The great part about metal and glass is that they can each be recycled constantly and not have the dangers associated with them like those of plastic. 

With metal and glass, they can be lumped together, broken down, or reused, and their integrity will not be compromised.

It is still a good idea to rinse out your metal and glass containers and bottles after you are done with them, but you can rest assured that they have the best chance of being recycled properly.

Why Not Switch To All Metal And Glass?

Plastics have certain stipulations on how to recycle, yes, but we’ve also seen a lot of research and science to show how plastic can even get into our food and therefore into our bodies.

So why don’t we make the switch from plastic to metal and glass? The short answer – is money.

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Metal and glass are both much heavier materials than plastic, making them more expensive to transport. 

There is also the risk of items breaking while being transported. 

With plastic, they’re more durable, less likely to smash and get that particular contents everywhere, and are lighter which makes it a real money saver to companies shipping them.

If you are extra concerned about the environment and want to make sure your recyclable items get to a recycling facility, then it is recommended to buy things packaged in metal or glass. 

It might cost a little more, but this slight inconvenience can help ensure proper recycling from start to finish.

Non-Recyclable Items

Below is an outlined list of non-recyclable items that will undoubtedly have to be sent to a landfill if you try to put them in your traditional recycling bin. 

That also might mean your entire recycling bin becomes trash.

  • Paper: dirty napkins, pet food bags, dryer sheets, wax paper
      • If you do have shredded paper, that should be placed in a separate bag within the rest of your recyclables. 
  • Styrofoam (cups, coolers, packaging): Most styrofoam is labeled with the #6 resin code inside the recycling triangle, but styrofoam actually should not be recycled because there isn’t enough of it left after being broken down to make it into something useful. 
  • Cardboard (storage and serving containers, pizza boxes, dirtied cardboard): For cardboard, the biggest thing is if it’s dirty or not. For example, a pizza box is likely going to be too greasy and covered with too many scraps to be recycled properly. If too much food and grease (anything that could contaminate the container) make it into the recycling container, then it will all be labeled ‘contaminated’ and sent to the landfill. 
  • Plastic (Ziploc bags, bubble wrap, cling wrap, candy wrappers, plastic bags, 6 pack fasteners): Outside of the plastics already outlined in this article, anything that does NOT have the plastic triangle with a resin code should never be put in your recycling bin. 
  • Glass: The only types of glass that cannot be recycled is tempered or windowpane glass, as well as mirror due to the coating and treatment of the glass. As mentioned above, glass is one of the few recyclable materials that can be recycled infinitely.
  • Aluminum: The only issue with aluminum is if it is dirty or not. So, things like aluminum foil and tin cans are fine to recycle, so long as they are cleaned. Foil will be tougher to clean so that’s probably easiest to just throw in the trash from the start.
  • Clothes Hangers: Wire hangers aren’t typically 100% metal, and the plastic ones aren’t always 100% pure plastic, causing both to not be recyclable. Aside from that, the curved nature of the hangers can also pose a problem when facilities are trying to sort through their load of recycled goods.
  • Scrap Wood: Depending on your city and recycling program, untreated scrap wood may be recyclable. However, if the wood is treated in any fashion at all, then it cannot be recycled due to the chemicals inside it.
  • Caps and Lids: Bottle caps and lids need to go in the trash because they are made from a different material than the rest of the glass or plastic container it was sealing.

It seems like a lot to understand what can be recycled and what can’t when we used to think it was so simple. 

Hopefully, this list helps inform you on what to look for when deciding if something can go in the recycling bin or not. 

However, after understanding the differences in recyclable materials, it gets easier to learn how to separate them accordingly. 

Consequences Of Recycling Dangerous Plastics

Even though plastic is more cost-effective, durable, and can be used for many everyday things, there are still disadvantages to using and recycling the varying types of plastics.

Health Problems

When plastics are melted down to be converted into other materials, there are unavoidable fumes that are produced that can be harmful to not just the environment but humans as well. 

There is a component of plastic known as “plastic resin” which is a part of the manufacturing process, and also comes from petroleum.

It is possible that this chemical can find its way into foods stored in plastic containers. 

Additionally, the USDA’s stance on plastic containers is that they can be made safely and approved for food storage, and for some, even heating foods up in the microwave. 

Even though the USDA doesn’t directly say there are harmful variants in plastic containers, there is still a chance that those fumes and chemicals can get into your food. I

If you want to use plastic storage containers for the sake of cost efficiency and ease of storage, then it is recommended that you try to find 100% approved (virgin if possible) plastic containers. 

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This will be your safest bet on reducing the chance of getting harsh chemicals in your containers and food as much as possible.

Furthermore, even with the proper storage containers, it is still advised to heat up your leftovers in a more microwave-safe dish like a traditional plate or glass container. 

Also, many health experts will advise trying to stay away from resin codes #3 (usually found in pipes) and #6 (most styrofoam products). 

Environmental Issues

Those same fumes that can be harmful to your food and overall health are the same fumes that can also be one of the drivers of environmental issues. 

When the plastics are heated and melted down, those same gases and fumes can get into the atmosphere and cause some issues with global warming. 

We’ve all heard the saying, “Too much of anything can be a bad thing.” 

This is a prime example that even with the global effort to improve our environmental situation, certain dangers are just a little unavoidable in the grand scheme of things. 

Therefore, the best we can do is continuously look at how to improve the processes and emit as few carbon emissions as possible.

Recycling Decreases The Quality Of The Plastic

Plastics are made out of long chains of atoms that are longer than those found in nature, and the length of these chains is a direct correlation to how flexible, strong, and lightweight the plastic is.

Unfortunately, the more plastic is recycled (i.e. broken down), the shorter those long chains of atoms get. 

This can greatly reduce the quality and purity of the plastic, and they will eventually be broken down too many times to be used for anything useful.

Therefore, the recycling facility will dispose of the unusable plastics at the landfill.

When plastic is recycled, there are virgin materials added to it to help upgrade its overall value, so recycled plastic items have been mixed with new materials to increase their quality.

On average, the same piece of plastic can only be broken down and recycled 2-3 times before it loses all integrity and can’t be used for anything else. 

Items That Can Be Recycled

Although we’ve been working towards identifying plastics that cannot be recycled, it might be helpful to know the easy wins when you come across them:

  • Paper: 
      • Brown paper bags
      • Newspaper
      • Office paper 
      • Phone books
  • Plastics: 
      • Soda and beer bottles
      • Water bottles
      • Oven ready meal trays
      • Sports drink bottles
      • Binders
      • Plastic pipes
      • Produce bags
      • Squeezable bottles
      • Medicine bottles (empty of course)
      • Drinking straws
      • Ketchup bottles (cleaned out)
      • Butter tubs and tubs similar (cleaned out)
      • Plastic tableware
      • Some Tupperware
  • Aluminum: 
      • Aluminum foil (as long as it does not have food residue)
      • Tin can (cleaned out)
      • Pie tins (cleaned out)
      • Steel cans (cleaned out)
  • Cardboard:
      • Flattened cardboard
      • Cereal boxes
      • Snack boxes
      • Dairy and juice containers
      • Toilet paper and paper towel rolls
  • Glass:
    • Any color of glass bottle and jar (cleaned out)

It might seem as though we have found more products that actually can’t be recycled when we thought we were doing the right thing by recycling them. 

This just shows there is a lot that goes into the recycling process and how much it is a revolving circle.

Therefore, whether it starts or ends with the consumer or recycling facility, each party must do their part in ensuring the other can do theirs.

On the side of the recycling facility, they must provide a safe product for consumers to enjoy without concern for negative health side effects. 

However, consumers must be able to identify the plastics that can easily go into our curbside recycling bins.

Additionally, we must be able to identify the materials that need a special degree of care, or if they’re better off going in the trash.

To learn more, you can also read our posts on whether you can recycle number 5 plastics, whether you can recycle Tupperware, and whether you can recycle toothpaste tubes, boxes, and toothbrushes.


This article should act as a guide as to what to watch out for, how to dispose of certain recyclable materials, and if certain everyday items can even be recycled or if they need to go straight to the trash.

There’s no doubt that plastics have their place in terms of storage, cost, and especially for those in the business of transporting materials. However, it is the hope that these companies know the dangers still associated with plastics and look for ways to reuse and repurpose them.


  • Jean Richardson

    Jean Richardson is a lover of knowledge, in all forms. He has spent over 15 years as a high school teacher, instructing students in history, geography, mathematics, and more.

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