Recycling has become one of the most important acts of humanity as the environment we live in is impacted by the plastic wastes we make. Although the numbers of recycling efforts increase, the plastic materials we dispose of do not.

The most difficult plastic to recycle includes polycarbonates, multi-resin and mixed plastic materials. The plastic, as mentioned above, is categorized under resin identification number 7, which indicates that the material can only be recycled and processed by only a few recycling facilities.

In order to know what plastic materials are easily recyclable or not, it is important to know the primary materials that some products are made out of, as well as what type of materials can be recycled.

Recycling Plastic

There are numerous types of plastics being used by people globally. Because disposable plastics can seriously harm the environment, it is a good habit to begin recycling them, whether in your household or as a community.

Why Recycling Plastics Is Difficult

Although plastics are beginning to be recycled in increasing numbers throughout the world, plastics out there prove to be more difficult to recycle than others. 

Plastics are categorized into seven numbers, and the higher the numbers are, the more difficult they get to be recycled. Every town and city will have different policies regarding the accepted materials being processed in their respective recycling programs.

So, despite that you are keeping up the habit of putting every plastic-made object you have into your recycling bin, some of the numbered plastic items do not necessarily mean that they will be processed in the local recycling program. 

Before putting all the hard work into recycling every single one of them, see and check the recycling program of your respective area and confirm if the plastic materials you are collecting, whether they are numbered 1 to 7, can be recycled.

Numbered Plastic Objects and Their Meaning

Many people have the misconception that the numbers that are found on many plastic products indicate that the plastic product is recyclable. Well, true, to an extent. 

The numbers found on plastic products are actually a resin identification code. This resin identification code provides you with what kind of plastic the plastic product is made out of. From there, you can find out from the resin identification number if the material can be recycled in your area or not. 

Commonly Recycled Plastics

When you find a plastic object, you will commonly find a number somewhere on its surface. The numbers are between 1 to 7. 

Below are the first two resin identification numbers, meaning that it is the most commonly recycled plastic, which are:

  • One: Polyethylene Terephthalate (PETE)
  • Two: High-Density Polyethylene (HDPE)

Now, let’s move on to the plastics which are less commonly recycled and harder to process.

Less Common Recycled Plastics

Plastics with a resin identification number of 3 to 7 are within the category of tougher plastic products to recycle. The plastic products with these resin identification numbers 3 to 7 are also not commonly collected in local recycling programs, especially recycling programs in small towns or cities. 

Below is the description of the resin number identification 3 to 7:

  • Three: Polyvinyl Chloride (PVC)
  • Four: Low-Density Polyethylene (LDPE)
  • Five: Polypropylene (PP)
  • Six: Polystyrene (PS)
  • Seven: Other Plastics 

So next time when you purchase a plastic-made product, and so it happens that it has a resin identification number on its surface, then you’ll know what it’s made out of. It would help that if your goal were to limit plastic waste, then stay away from any product with a resin identification number from 3 all the way to 6.

What Is the Hardest Plastic Material To Recycle?

As mentioned before, the resin identification number indicates the recyclability of the plastic-made product. Resin identification numbers 1 and 2 are considered more widely recycled by recycling programs, while usually 3 to 7 is more difficult as only a few recycling programs are able to process them.

Plastic products marked with the resin identification number 7 are considered the most difficult to recycle. These plastic-made products with resin ID code 7 are commonly made out of polycarbonate (PC) material, which is the most difficult plastic to recycle in any recycling program. 

This type of plastic can be found in products such as:

  • Water cooler bottles
  • Large plastic containers
  • Mixed plastic products

Polycarbonates (PC) is a tricky and not-so-cheap material to process. One of the methods that some recycling plants do is to recycle polycarbonate by using chemical recycling. 

Using Recycled PolyCarbonates

When you use recycled Polycarbonates, the product may show lesser durability. Furthermore, the recycled PC also has reduced impact resistance compared to a newly manufactured and more resilient PC. 

Recycled PC is widely used for:

  • Bottles
  • Plastic containers
  • Plastic lumber uses

Other plastic-products that fall under resin identification number 7 may also include products made out of multi-resin and mixed plastic materials. 

Anything under resin identification number 7 will prove to be the most difficult and resource-taxing to recycle. This is also primarily why most recycling plants do not choose to recycle plastic products under resin identification number 7.

Other Plastics That Are Difficult To Recycle

Although plastic materials with the resin ID code of 7 are the most difficult to process, there are other plastic materials out there as well that prove to be almost or as difficult to recycle. Below are other types of plastic materials that are incredibly difficult to recycle.

Resin ID Code Six: Polystyrene

Polystyrene (PS) comes in second place in becoming the most difficult plastic to recycle.

Just like the materials under resin identification number 7, the PS is a difficult and expensive material to recycle. This is primarily because of the material’s low density, which is 98 percent air.  

PS can usually be found in products including: 

  • Single-use coffee cups 
  • Takeout food containers
  • Styrofoam

Now, let’s take a look at how PS is recycled.

How Polystyrene Is Recycled

To recycle PS, you must locate or ship the product to a recycling facility that is capable of doing so. A recycling facility capable of processing PS does so by compressing the material to recycle and reuse them. 

Once the recycling process is complete, recycled PS can be used in several other products, which may include:

  • Thermal insulation
  • Desk trays
  • License plate frames
  • Plastic moldings 
  • Protective packaging
  • Thermometers
  • Light switch
  • Eggshell cartons
  • Camera or video cassette casings

Below polystyrene in the recycling-difficulty rank will be polypropylene, another plastic material difficult to process in recycling facilities.

Resin ID Code Five: Polypropylene

Polypropylene (PP) is considered the least recycled post-consumer plastic, with only less than 1 percent recycled. PP can be commonly found in products including:

  • Caps
  • Snack containers (Pudding, yogurt, etc.) 
  • medicine bottles
  • straws

Now, let’s take a look at how PP is recycled.

How Polypropylene Is Recycled

One of the reasons that PP has the lowest recycling rate is due to the production rate as well as the recycling process, which involves 5 steps, including: 

  • Collection
  • Sorting
  • Cleaning
  • Reprocessing by melting
  • Producing new products from recycled PP 

There are several things to note about the melting process. The melting process for PP involves two steps. The first step is to melt PP approximately around 250° Celsius in temperature. 

The first step will ensure that any contaminant molecules and residual molecules are eliminated. In the second step, the PP will be placed under vacuum and solidification at a temperature of approximately 140° Celsius. 

What Can Recycled Polypropylene Make?

After this process is complete, the product goes through the final step to produce a new product mixed with recycled PP. The mixed ratio of recycled PP and virgin PP is up to 50 percent. Once complete, the new PP product can be used in plastic products such as:

  • Car battery cases
  • Shipping sheeting and trays
  • Lights
  • Battery cables
  • Brooms 
  • Oil funnels
  • Ice scrapers
  • Garden rakes
  • Storage bins

Below polypropylene is low-density polyethylene, a plastic material that is difficult to process but still accepted in some recycling facilities.

Resin ID Code Four: Low-Density Polyethylene

Low-Density Polyethylene (LDPE) is a soft and highly flexible plastic material that is often used to produce products such as: 

  • Bakery and bread bags 
  • Frozen food bags
  • Plastic shopping bags

Now, let’s move on to how LDPE is recycled.

How Low-Density Polyethylene Is Recycled

In order to recycle LDPE effectively, you must first separate the plastic film. Once you have separated them, this will split into two films: LDPE and high-density polyethylene (HPDE). 

On top of separating the two films, the clear films should also be separated from the colored or printed films. This will help better maintain their specific properties during the recycling process.

Once a recycling plant is done processing LDPE, the recycled final product can be used in a variety of other items, including:

  • Floor tiles 
  • Garbage can liners
  • Compost bins
  • Trash cans
  • Shipping envelopes
  • Furniture
  • Landscape timber
  • Outdoor lumber

Aside from low-density polyethylene, polyvinyl chloride is another material that is equally as difficult to process and equally accepted as polyethylene throughout recycling facilities.

Resin ID Code Three: Polyvinyl Chloride

Polyvinyl Chloride (PVC) can usually be found in a variety of products such as:

  • Drainage pipes
  • Window frames
  • Vinyl
  • Blood storage bags
  • Paneling
  • Fences
  • Some types of bottles

They are one of the most commonly produced and used plastic materials, which also makes them one of the most disposed of. Therefore, recycling PVC is crucial, and it is not difficult either.

Why You Should Recycle Polyvinyl Chloride

When someone disposes of a PVC-based product, it will usually last in the environment it was disposed of for at least 30 years. Furthermore, some PVC-based products even reach up to more than 50 years.

One of the things to note when recycling PVC is its high chlorine, especially in its raw form, which can reach up to 56 percent of the product’s weight. In addition to the high level of chlorine, PVC also has a high level of other hazardous chemicals added to attain the material quality.

What Can Recycled Polyvinyl Chloride Make?

Once PVC has been recycled properly in a recycling facility, it can be used in various products. Below are what PVCs normally go into after being recycled:

  • Piping
  • Mats
  • Fencing
  • Gutters
  • Electrical boxes and cables
  • Garden hoses
  • Traffic cones
  • Mobile home skirting
  • Packaging sheets 
  • Film 

Now that the difficult plastic materials to recycle have been covered, surely covering the easiest plastics is a must. There are two plastic materials that will be covered below.

What Type of Plastics Are Easy To Recycle?

There are essentially two types of plastic material that can be easily recycled in all recycling facilities. Below are the following plastic materials.

Resin ID Code One: Polyethylene Terephthalate

Polyethylene Terephthalate (PET) is considered as one of the two easiest plastic materials to recycle. PET is essentially a clear and durable plastic that is often used in single-use containers, including:

  • Supermarket snacks containers 
  • Beverage bottles
  • Vegetable and olive oil containers
  • Some frozen food containers

Now, let’s take a look at what PET can make when recycled.

What Can Recycled Polyethylene Terephthalate Make?

All recycling facilities accept PET. Once it is processed, it will be called recycled polyethylene terephthalate, or RPET. Additionally, RPET is also the most widely used recycled plastic in the world. Once a recycling facility has completed its process to produce RPET, it will go into products such as:

  • Fiber for carpet
  • Fleece jackets, comforter fill, tote bags
  • Containers for food and beverages
  • Film and sheeting
  • Strapping

Now, let’s move on to the next plastic material that is easy to recycle.

Resin ID Code Two: High-Density Polyethylene

High-density polyethylene (HDPE) is essentially a hard plastic, which is similar to PET. The difference is that HDPE is not as transparent as PET and are often used on products such as: 

  • Household cleaners
  • Shampoo bottles 
  • Small containers (Pudding, yogurt, etc.)

Again, similar to PET, HDPE is accepted in all recycling facilities throughout the world as it is considered as one of the easiest plastic materials to recycle. Recycling companies often collect HDPE materials, along with PET, and take them to recycling facilities to be processed.

What Can Recycled High-Density Polyethylene Make?

Once HDPE is processed in the recycling facility, it can be used on the following products:

  • Containers for cleaning-related items (shampoo, soaps, cleaners, etc.)
  • Plastic lumber
  • Recycling bins
  • Floor tiles
  • Buckets
  • Flowerpots 
  • Garden edging
  • Film

Many people throughout the world have now been more environmentally aware and have been collecting and recycling the two plastic materials mentioned above. This is primarily because of how easy it can be used and turned into another usable product.


Polycarbonates, multi-resin, and mixed plastic materials, which are false under resin ID code 7, are extremely difficult to recycle. Recycling facilities require time as well as resources in order to break down and process these materials. Furthermore, there are only a few recycling plants that do so. For the sake of mother nature, let’s hope that will change in the near future.


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