Polystyrene is a versatile plastic that is made from liquid monomer styrene. It is identified by resin identification number 6. It can be made into hard plastic or foam. It’s an extremely versatile plastic, its uses range from single-use food containers to children’s toys to wall insulation in buildings.
In this article, I will discuss whether polystyrene is recycled. Additionally, I will list the various uses of polystyrene and how over-use of this plastic is harming our environment.
Can polystyrene be recycled?
Yes, Polystyrene is 100% recyclable. However, several obstacles keep the recycling rate of polystyrene abysmal at only 12% globally.
The monomer used to make Polystyrene is a liquid hydrocarbon which like all other plastic monomers is sourced from fossil fuels. This monomer, styrene, is also naturally occurring in nature, found in certain tree saps, coffee, beef, cinnamon, and strawberries.
Polystyrene (PS) is mainly of two types, foam and hard plastic. PS can be mixed with air to make plastic foam which is usually around 98% air with only 2% PS.
PS foam has two main types, expanded polystyrene (EPS) and extruded polystyrene (XPS).
EPS is generally more lightweight and soft, which makes it an excellent material for single-use food packaging.
XPS on the other hand is more dense foam, it’s brand name is Styrofoam which is made by the Dow Chemical Company.
Styrofoam is used for roof, floor, and wall insulation in homes and offices.
Polystyrene has a wide range of uses. It’s used to make materials such as insulation, medical devices, home appliances, laboratory equipment, electronics, and automotive parts.
Polystyrene can also be used as a hard plastic. Many everyday items are made from PS such as many children’s toys, yogurt cuts, food packaging, plastic silverware are a few examples.
High-quality material made for home appliances, the automotive industry, and lab equipment is made from hard polystyrene.
Even though polystyrene is 100% recyclable, several obstacles keep most polystyrene from reaching the recycling centers. Recycling PS is discussed in detail in the next section.
How is polystyrene recycled?
For hard PS, the process is rather straightforward. The plastic is sorted, cleaned, and shredded into smaller pieces. Then heat and pressure are applied to melt the plastic to combine all these parts into large chunks. These chunks are then ground to form pellets.
These pellets are then sold to plastic manufacturers to make a host of products like clothing hangers, outdoor furniture, window, and door frames, roofing tiles, etc.
However, for polystyrene foam, the recycling process is made more complex due to presence of air in the plastic.
For EPS and XPS, there are several techniques to recycle them. These are grinding, compacting, and densifying.
- Granulation- lighter density polystyrene like EPS is fed into a machine that separates the foam down to its basic granules. These granules are then mixed with newly-made EPS granules to make new material.
- Compacting- usually denser polystyrene foam like XPS or some EPS are fed into a machine which presses them extremely hard until the air escapes all pockets of the foam. The remaining material is hard polystyrene which is then granulated or pelletized to make an array of materials.
- Densifying- in this method polystyrene foam, mostly EPS, is first shredded. Then heat and pressure are applied to create hard polystyrene which is then pelletized to make plastic objects.
In most countries, polystyrene is not recycled in the general recycling center where materials like paper, aluminium, or PET is recycled. It is recycled in specialized centers.
Different cities have different policies and it’s very important to know how your city recycles PS, there is a chance they do not recycle it at all. You can find this information online on your local government’s website.
Some cities have PS drop-off points where you can drop your PS waste. There are collection programs arranged by private companies that often collect PS foam from designated areas like college campuses.
They usually advertise these collection programs online and in person so you can keep your eyes and ears open for that.
The rate of PS recycling is abysmal in most parts of the world, particularly in the US, most EPS-based single used plastics are not recycled.
PS foam or EPS is mostly used to make food containers and single-use cutlery, which means these are often stained by grease from food, which makes it very hard to recycle.
It takes extra effort by recycling plant workers to separate the foods from each container, which is a serious set-back.
After China stopped importing plastic waste from most of the developed world, the flawed, inadequate, and inefficient recycling systems of the US came in full view.
Most Americans throw all their recyclables into a single-stream recycling system, in the past, this was less of an issue as these materials were sorted overseas.
This isn’t an option any longer, and since workers in American plants are overwhelmed by the amount of waste coming in, the process has become slow.
The good news is, there are recycling companies, although rare, who take all EPS products. Many of them have mail-in services for which you carry the cost. Some companies may have drop-off sites or pick-up services for a price as well.
One such company in Mexico, Renneuva, collects EPS waste from the locals. They, unlike most other recycling programs, do not say no to EPS used as food containers. They have collection sites and drop-off programs with local companies and households from whom they collect the polystyrene foam.
After cleaning and sorting, the material is ground to a manageable size. Then by the process of densification small pellets of PS are made, which are then sold to a local frame-making company, where these pellets are turned into window and door frames.
Companies like Rennueva are beginning to rise in other big cities as well, which is excellent news.
Polystyrene foam in landfills take up an incredible amount of space due to its bulky nature, moreover, due improper waste disposal systems in certain countries, PS foam ends up in the world’s oceans and rivers.
The level of pollution PS foam causes is immense, and requires serious attention.
Impacts of PS pollution on human health and the environment:
The biggest offender to the environment out of all PS material is EPS. This is because this material is extremely cheap and easy to make, its insulation, and cushioning properties make it perfect for carrying food items, and for packaging.
Packing peanuts, polystyrene blocks used to pack electronics, and other fragile materials into boxes are just some examples of using EPS as a cushion. Most of these foams are not reused and end up in landfills.
Companies like UPS do accept packing peanuts that were already used, only 30% or so is kept in circulation. The rest inevitably end up in landfills.
Depending on where these landfills are, it can cause damage to life around it. Small animals very often consume small pieces of plastic from landfills. This blocks their digestive tracts or sometimes results in them choking.
Scientists estimate that polystyrene takes a minimum of 500 years to decompose. This essentially means that EPS products sit in our landfills forever without decomposing.
One other horrifying fact is that millions of tons of EPS are made each year globally. Most of these end up in landfills without proper recycling systems. EPS takes up around 30% of the landfill spaces on average.
There are efforts taken by certain governments to ban single-use items made with PS, however, this needs to be a concerted effort among all the governments. Otherwise, these policies will not have the desired impacts.
Most modern landfills in Europe are closed systems, but most other landfills in the world are not and this causes a significant amount of plastic to leak into the oceans. The garbage patches that have formed in our oceans are mostly made of plastic waste with a large portion of it being polystyrene foam.
This foam breaks down under the sun into microplastics and enters the food chain of marine life. They accumulate in the digestive tracts of marine creatures which eventually clogs their tracts leading to a slow and painful death.
In many cases, PS microplastics can persist in marine life and enter our bodies when we eat seafood. One detrimental aspect of PS is that it slowly breaks down into styrene which is a carcinogen.
There isn’t sufficient evidence with which we can decisively say that the plastic in our food chain is going to cause cancer, however, we cannot decisively say it will not cause cancer, and therein lies the problem.
The best approach to minimize PS pollution is to minimize its use. This can be done by a more efficient recycling system, outright bans of the products, reusing old PS foam, and finding alternatives. Over the years several alternatives have been developed.
Alternatives to Polystyrene:
Unfortunately, there aren’t any feasible alternatives to hard PS or XPS. However, there have been some alternatives to EPS that are being developed.
A better, environmentally packing peanut is available which is made entirely out of cornstarch. These peanuts are biodegradable, which makes them far more desirable.
There are companies now that are making PS foam-like material from mushrooms. These mushroom foams are quite versatile and can be used to make cushions for electronics or egg cartons, just like EPS. Lowering production costs and directing more funding into these alternative materials will cut down on plastic waste drastically.
Instead of using PS foam to make takeaway containers, many restaurants are now using aluminium trays for takeaway packaging. These trays can be cleaned and thrown into the general recycling bin where they can be easily recycled as aluminium is a metal that can be recycled indefinitely.
Better policies, more extensive recycling systems, investing in sustainable alternatives are all necessary steps we need to make to cut down on PS consumption.
Recycling plastic is economically, and ethically the right thing to do. It cuts the cost of raw materials, energy, and production while reducing CO2 emissions and energy expenditure. It’s a win-win situation if a proper system is set in place.
In this article, I discussed whether polystyrene is recyclable or not. Additionally, I discussed the different types of polystyrene that are available, their impacts on the environment, and possible alternatives to this plastic.
Frequently Asked Questions (FAQs): Is plastic 6 recyclable?
Is number 6 plastic recyclable?
Yes, it is 100% recyclable. However, many municipalities do not accept EPS, instead, they have drop-off points. Make sure you check it out before you recycle it.
Does polystyrene harm our health?
Potentially, yes. There is no conclusive research that suggests that PS causes serious health issues. However, styrene is a known carcinogen. This is why EPS food containers should not be used to carry hot food since the heat may cause the plastic to degrade and the monomer to be released.
What can I do with #6 plastic?
Plastic number 6, better known as Polystyrene comes in three types, hard, EPS, and XPS. These types have a milieu of uses. Hard PS is used to make hangers, toys, yogurt cups, etc. EPS is very light and used to make takeaway food containers, coffee cups, packing peanuts, etc. XPS is used to make Styrofoam, which is used to make roof insulation, floor insulation, and ceiling insulation in houses.
Should I put polystyrene in the trash?
It depends, check your city’s recycling policy first. Some cities recycle polystyrene. Also, some cities have drop-off sites for polystyrene, do check that.
Should I recycle polystyrene?
Yes! If your area accepts polystyrene for recycling you absolutely should. Polystyrene build-up is a huge issue in landfills and ocean garbage patches, it’s better to do our parts.
What to do with polystyrene packaging?
Polystyrene packing peanuts are reusable. UPS even accepts these packing peanuts if you drop them off or give them to the delivery person. You can reuse the packaging yourself or repurpose it around the house.
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