The Chemicals in Plastic and Why it Matters, Part 2

Colorful plastic litter organized by color on a beach.
Image by Filmbetrachter from Pixabay

Plastics are made from chemicals and petroleum, which you read about in Part 1 of this series. Today, I want to tell you about the chemical contents of plastics by resin code, the number on the bottom surrounded by a triangle. More importantly, I want to inform you of the ways they may be toxic to our health.

Resin Identification Codes (RICs)

Resin symbol for #1 plastic, or PET.
Image by OpenIcons from Pixabay

The plastics industry created RICs in 1988 as part of their campaign to boost plastic’s image. They even lobbied to have state legislatures adopt them. But this little symbol on almost all plastic packaging is misleading. Many assume that the recycling symbol or RIC means that a package is automatically recyclable. However, that is not true, it actually only refers to the type of plastic resin used.

To reduce confusion, ASTM, the organization that regulates the RIC system, updated the symbol from the chasing arrows to a solid triangle in 2013. “However, manufacturers aren’t required to change their equipment to incorporate the new symbol, which is why you still see the arrows on many plastic products,” according to an article on Oceano.org.1 So it’s still easy for people who don’t know to mistake the RIC as a recycling symbol versus an industry tag for the plastic.

Graphic comparing the types of recycling symbols used with RICs.

A clear plastic PET food container showing the updated symbol, a numbe 1 inside of triangle.
Example of a plastic PET food container showing the updated symbol. Photo by me

The RICs / Types of Plastics

Resin Identification Coding System graphic
Image courtesy of Wikimedia Commons

Next, let’s look at the 7 RICs and types of plastics, what they are used for, their characteristics, their chemical contents, and their potential toxicity. Note that this is not an exhaustive list; nor is each category exhaustive in the standard products or characteristics.

#1 PET/PETE: Polyethylene terephthalate

Standard products: Water bottles, soda bottles, food containers such as cooking oil and peanut butter, wrinkle-proof clothing, fleece blankets, padding in pillows and comforters, carpeting, other polyester fabrics.

About: PET is the most valuable type of plastic and the most recycled. There are typically two types: one is made with a blow molding machine; the other is thermoform which is made by heating a plastic sheet until pliable and then molded into a specific shape. The main difference is in molecular weight. Higher molecular weight items, such as bottles and jugs made from blow molding, are more valuable than their thermoform counterparts. Thermoform, though more difficult to sell, is often recycled into carpeting.2

Chemical content: “A chemical called antimony trioxide is used as a catalyst and flame retardant in making PET, and this antimony additive is considered a possible carcinogen.” The amount in one single water bottle is minimal, but leaching increases with heat. Think of those water bottles stored in the car during the summer. “There is research showing that PET may leach phthalates too, even though the plastics industry says that phthalates are not required to make PET.”3 Regardless, think about switching to metal or glass containers whenever possible.

Close-up of clear blue water bottles
Image by pasja1000 from Pixabay

#2 HDPE: High-density Polyethylene

Standard products: Milk jugs, water bottles, juice, bottles, bleach, dish and laundry detergent bottles, shampoo and conditioner bottles, cleaner containers, over-the-counter medicine bottles, cereal box liners, Tyvek home insulation, plastic-wood composites, snowboards, 3D printing filament, and wire covering. It is even used in some plastic surgery procedures.

About: This is one of the most widely used plastics because of its versatility. It is strong, flexible, cost-effective, moisture-resistant, and resistant to most chemical solvents. It has high tensile strength and has both a high-impact resistance and melting point. “The polyethylene polymer has the simplest basic chemical structure of any polymer, making it easy to process and thus extremely popular for low value, high volume applications.”4

Chemical content: While this is considered a ‘safer’ plastic for food and drink use, there is evidence that these release endocrine-disrupting chemicals, especially when exposed to UV. “The main leaching culprits are estrogen-mimicking nonylphenols and octylphenols, which are added to polyethylene as stabilizers and plasticizers.”5 Those chemicals disrupt the body’s hormones and can cause cancer, reproductive problems, birth defects, and other developmental disorders.

Angled photo of plastic milk jugs at the supermarket.
Milk jugs are typically #2 HDPE. Photo by me

#3 PVC: Polyvinyl Chloride

Standard products: Think all vinyl products. Shower curtains, medical bags, medical tubing, shrink wrap, children’s toys, binders, school supplies, plastic furniture, garden hoses, vinyl clothing and outerwear, wire and cable insulation, vinyl records, carpet backing, flooring, credit cards, clamshell packaging, plumbing pipes, vinyl siding, window frames, fences, decking, other construction materials.

About: “PVC can take on a staggering variety of personalities – rigid, filmy, flexible, leathery – thanks to the ease with which it can be blended with other chemicals.”6 PVC is versatile as it can be adapted to many applications depending on the plasticizing additives. It is strong and resistant to moisture and abrasion. It can be produced clear or colored. About three-quarters of all vinyl produced goes into construction applications.

Chemical content: PVC is known as the poison plastic because it leaches toxins for its entire life cycle and should be avoided whenever possible. Vinyl is manufactured by polymerizing a chemical called vinyl chloride. It can contain up to 55% additives, mainly phthalates. The chemicals it may release during its lifetime include cancer-causing dioxins, endocrine-disrupting phthalates, bisphenol A (BPA), lead, mercury, cadmium, and other heavy metals. “The problem with PVC is that its base monomer building block is vinyl chloride, which is highly toxic and unstable, thus requiring lots of additives to calm it down and make it usable. But even in its final ‘stabilized’ form, PVC is not very stable.”7 The additives leach out and you can inhale and ingest them.

White PVC pipes stacked at a manufacturer or store.
PVC pipes, photo by Dennis Hill on Flickr, Creative Commons license (CC BY 2.0)

#4 LDPE: Low-density Polyethylene

Standard products: Film applications like bags, such as those used for bread, shopping, dry-cleaning, newspapers, frozen foods, produce, and garbage. Also used for shrink wraps, linings for cartons and cups, container lids, some squeeze bottles, orthotics, and prosthetics.

About: LDPE is a soft, flexible, lightweight plastic material, known for its low-temperature flexibility, toughness, and corrosion resistance. But it is not recyclable in any practical sense. Citing data from the Environmental Protection Agency (EPA), one large recycling corporation noted that “the overwhelming majority of products made from LDPE end up in landfills…Dumping tons of LDPE in landfills can have devastating consequences…plastic buried in landfills can leach into the soil and introduce chemicals into the groundwater.” They can threaten marine life in coastal areas, and “lightweight plastic bags can be blown great distances by the wind, ending up in bodies of water where animals eat them or become tangled in them.”8 Plastic bags causes huge environmental problems.

Chemical content: These can leach some of the same chemicals as #2 HDPE plastic. It is a thermoplastic made from the polymerization of ethylene. While ethylene is considered a building block of plastic, it is highly flammable and reactive. It is created by Ethane Cracker Plants, which use an environmentally questionable process to extract the ethane to make ethylene. While difficult to avoid, steer clear of this plastic whenever possible.

Angled photo of the bread aisle at the supermarket.
Bread bags are typically #4 LDPE. Photo by me
Blue plastic cap from a gallon milk or water jug, #4 LDPE plastic.
Blue plastic cap from a gallon water jug, #4 LDPE plastic. Photo by me

#5 PP: Polypropylene

Standard products: Polypropylene is used in packaging, yogurt cups, sour cream and soft cheese containers, prescription bottles, butter/margarine containers, plastic to-go containers, leftover containers, freezer meal containers, the filter cases of some disposable home water filters, electrical wiring, and plastic bottle caps because polypropylene can withstand pressure. It is also used in vehicles for bumpers, carpets, and other parts. Polypropylene allows moisture to escape and stays dry, making it ideal for use in disposable diapers.

About: Polypropylene is sometimes referred to as the “safe” plastic, but there really is no safe plastic when it comes to food. All plastic has the capacity to poison us in certain circumstances. Polypropylene is a stronger plastic than other types, but it is generally not recyclable because there isn’t sufficient reprocessing capacity. Polypropylene is more stable and resists heat better than other plastics. So it is generally considered safer for foods and hot liquids because it leaches fewer chemicals (though it still does leach, which is why you should use glass or metal containers for your food).9 However, this is what many leftover and freezer meal containers are made from. Have you ever noticed rough patches or surface defects in your leftover containers? Any disruptions on the surface mean the polypropylene has been compromised, which increases the chances that it will leach chemicals into your food, especially when heating it.

If you have polypropylene leftover containers from before 2013, replace them. These contained phthalates and bisphenol A (BPA). And if you do replace them, please buy stainless steel or glass containers and just avoid the chemicals in plastic altogether.

Chemical content: Polypropylene is a rigid and crystalline thermoplastic made from the polymerization of the propene monomer. There is ongoing research about the health effects of certain additives leaching from polypropylene, such as oleamide, a polymer lubricant and a bioactive compound. Oleamide does occur naturally in the human body, but the long-term effects of synthetic oleamide are not yet known. In a 2021 study entitled “Plastic additive oleamide elicits hyperactivity in hermit crabs,” scientists found that it may be perceived as a feeding cue by marine species, thus increasing the consumption of microplastics.10

Angled photo of the yogurt shelves at the supermarket.
Yogurt and other dairy containers are typically #5 polypropylene. Photo by me

#6 PS: Polystyrene

“Most recognizable when puffed up with air into that synthetic meringue known technically as expanded polystyrene and popularly by the trademark Styrofoam.” -Susan Freinkel, author of Plastic: A Toxic Love Story11

Standard products: The foam form, called Expanded Polystyrene (EPS), also known as Styrofoam, is used in egg cartons, meat trays, single-use food and take-out containers, coffee cups, vehicles, bike helmets, packing peanuts, and home insulation. The rigid form is used for single-use food containers, cutlery, CD and DVD cases, disposable razors, etc. “It is also combined with rubber to create an opaque high impact polystyrene used for model assembly kits, coat hangers, electronic housings, license plate frames, aspirin bottles and medical and lab equipment, including test tubes and petri dishes.”12

About: It may be difficult to avoid this stuff in home insulation, vehicles, and bike helmets, but it should be avoided at all costs when it comes to food and beverages. I wrote a lot about polystyrene in my series on Styrofoam and polystyrene food containers. These containers and cups leach styrene into food and beverages and thus enter your body. Styrene is known to likely be carcinogenic. It is considered a brain and nervous system toxicant and causes problems in the lungs, liver, and immune system.

Chemical content: Polystyrene is a synthetic polymer made from the polymerization of styrene. It is a chemically produced plastic that can be made into a hard or foam plastic. The foam is created by expanding the styrene by blowing various chemical gases into it. Polystyrene is made from ethylene and benzene, both hydrocarbons derived from by-products of petroleum and natural gas (also known as petrochemicals).

Take-out in polystyrene containers
Image by albedo20 on Flickr, Creative Commons license (CC BY-NC-ND 2.0)

#7: OTHER Plastics

This is the catch-all category for all ‘other plastics.’ Any plastic items not made from the above six plastic RICs are grouped together as #7’s. These include acrylic, nylon, polycarbonate, epoxy resins, polylactic acid (PLA), and multilayer combinations of different plastics. These are never recyclable except through a few rare and expensive take-back programs, because of the vast array of resins and chemicals mixed together. Below are some of the individual plastic types that fall under #7.

Acrylic: This is a rigid thermoplastic that is strong, diverse, and resilient; and it can be clear or solid colored. Acrylics are used to make bulletproof windows, LEGOs, dental fillings and dentures, airplane windows, aquariums, shower doors, vehicle parts, helmets, and even textiles such as clothing, tents, and sails. This is a stable plastic and is considered a ‘safer’ plastic, except for certain ones used in dental applications. Those, specifically acrylic methacrylate resins, are suspected to be cytotoxic (toxic at the cellular level) because they leach chemicals such as formaldehyde and methyl methacrylate.13 That being said, keep those LEGOs out of your toddler’s mouths.

Red, blue, white, yellow, and black Legos in a small pile.
Photo by Alexas_Fotos on Pixabay

Nylon: This belongs to a group of plastic resins called polyamides that include Kevlar and Velcro. Invented by DuPont in the 1930s, nylon was originally invented to be a synthetic alternative for silk, for example, stockings. Nylon can be fiber, solid, or film. Items made from it include clothing, toothbrush and hairbrush bristles, rope*, instrument strings, tents, parachutes, carpets, tires, food packaging, boat propellers, skateboard wheels, and mechanical and automotive parts.

DuPont advertisement for Nylon from 1949, showing woman pulling up her Nylon stockings.
DuPont advertisement for Nylon from 1949. Image by clotho98 on Flickr, Creative Commons license (CC BY-NC 2.0)

*NOTE: Most rope and nets used in commercial fishing are made from nylon and present a huge problem in the oceans. The rope and nets break away from the fishing vessels and become threats to fish, sea turtles, and marine mammals who get entangled in them. Since nylon is plastic, it will not decompose and will remain in the ocean for decades or longer.

Seal on beach with nylon fishing net entangled around its neck.
Nylon fishing net entangled around the neck of a seal. Image by Noutch from Pixabay

Polycarbonate: Originally designed as an engineering plastic to compete with die-cast metal and substitute glass because it is lightweight, strong, transparent, and shatter-proof. In the past, it was used in reusable water bottles and baby bottles until bisphenol A (BPA) was ruled toxic. “It is still a favorite for rigid products including CDs and DVDs, eyeglass lenses, dental sealants, lab equipment, snowboards, car parts and housing for cell phones, computers and power tools.” It is also still used in the large, blue water containers common in offices.14 This type of plastic is good for items not related to food or beverage. However, we should use it less overall in other applications when possible to reduce waste, because when polycarbonate breaks it cannot be recycled.

Epoxy resins: Known for high strength, low weight, temperature and chemical resistance. Used in many applications: high-performance adhesives, coatings, paint, sealant, insulators, wind turbine blades, fiber optics, electrical circuit boards, and parts for carts, boats, and planes. They are also used on the interior lining of most canned goods. Avoid these when possible, especially with food and beverage containers because they contain chemicals such as bisphenol A (BPA) and epichlorohydrin. The latter likely causes blood, respiratory, and liver damage and is a probable carcinogen.15

Polylactic Acid (PLA): This is a bio-based plastic made from lactic acid, which is a fermentation product of corn or cane sugar. This is the most common bioplastic, used in a variety of products including clothing, bottles, weed cloth, gift and credit cards, food packaging, diapers, wipes, and disposable dishes. PLA is advertised as compostable but it is only biodegradable under industrial composting conditions, which is still largely unavailable.16

Polyurethanes

This large family of plastics was introduced in 1954. Polyurethanes do not have an assigned RIC, but they are worth mentioning because they are so common. They come in foamed versions that are soft and flexible for uses in mattresses, cushioning in furniture, cars, and running shoes, spray foam insulation, and carpet underlay. They can take on a flexible form for hoses, tubing, gaskets, seals; and they can be tough and rigid for items such as insulating lining for buildings and refrigerators. Polyurethane can also be made into thin films or coatings, such as adhesives for food packaging and waterproof coatings for wood. When it is spun into fibers, it makes Spandex, Lycra, and even latex-free condoms.17

Polyurethane is made from isocyanates, a chemical that is potentially toxic, as it is the leading cause of occupational asthma. “As for our day-to-day use, polyurethanes have also been linked to a skin irritation known as contact dermatitis through direct contact with such polyurethane items as a toilet seat, jewelry and Spandex tapes sewn into underwear.” It is highly flammable and may contain flame retardant additives that go in mattresses and spray foam insulation. Flame retardants are full of chemical combinations that are considered trade secrets, so the public does not know what potential toxins are present in their items. Spray foam insulation, even once cured, can off-gas isocyanate methylene diphenyl diisocyanate (MDI), which has been linked to asthma and lung damage.18

Person in white Hazmat suit applying purple spray foam insulation.
Image by justynkalp from Pixabay

What You Can Do

The best thing you can do is to keep learning, which you’re already doing if you’re reading this article. Stay informed and be aware of what chemicals you’re exposed to through plastics, packaging, and additives. Avoid those which are documented as toxic or even potentially toxic. Additionally, remember that few plastics are actually recycled, so reducing the plastics you purchase is essential to the environment and your health. Thank you for reading, please share and subscribe!

“We all need to separate the hopeful and increasingly fantastical act of recycling from the reality of plastic pollution. Recent data indicates that our recycling wishes, hopes, and dreams – perhaps driven in part by myths surrounding RICs – will not stop plastic from entering our oceans. Instead, if we truly want to protect the environment and marine life, we need to campaign for more plastic-free choices and zones, and for the reduction of plastic production and pollution.”19

 

Additional Resources:

11 Ways to Go Plastic-Free with Food

To learn more about Bioplastics: The Packaging Industry and How We Can Consume Differently, Part 3

The different types of plastics used in packaging: Guide to my Packaging Industry Series

More about polystyrene #5: Guide to my Styrofoam and Polystyrene Containers are Poisoning Your Food Series

Footnotes:

Styrofoam and Polystyrene Containers are Poisoning Your Food, Part 5

Chick-fil-a meal
Chick-Fil-A food and polystyrene cup. Photo by young shanahan on Flickr, Creative Commons license (CC BY 2.0)

In my series on polystyrene food containers, I’ve explained how it is used, produced, and why it is harmful to human health as well as the environment. I’ve examined why it is not practical to recycle polystyrene even though its producers would have you believe otherwise. In Part 4, we explored supposed alternatives and why they weren’t totally effective. Today, I want to discuss corporate responsibility and how bans on polystyrene can help bring greater change.

“When you know better, you do better.” -Maya Angelou

The Role of the Food Industry

Chicken Salad Chick polystyrene container, use for dine-in service.
Chicken Salad Chick polystyrene container, used for dine-in and take-out services. Photo by me

The fast-food and restaurant industries can play a huge role in ending the use of polystyrene. Many use polystyrene for their hot and cold drink cups and clamshell containers, but they have a choice in what they purchase. Most dine-in restaurants already use reusable dining ware and the ones that don’t could make the choice to switch and install a dishwasher. The initial investment would be higher, but the constant overhead of disposables would disappear and trash costs would go down. For take-out and leftover containers, there are many ways companies can offset the increased costs of non-polystyrene packaging. They could allow customers to bring their own containers and/or they could raise the cost of their products by mere cents. Companies have the opportunity to be part of the solution in order to protect our own habitat.

A few companies have self-imposed bans on polystyrene. McDonald’s phased out polystyrene containers for its sandwiches in 1990 after their containers became a symbol for litter. These containers are so well-known in advertising and consumer culture history that the Smithsonian has those containers in their archives.1 It stopped using polystyrene for hot beverages in 2012 after being pressured by environmental groups, and they were supposed to end the use of cold beverage cups by 2019. Dunkin’ (formerly known as Dunkin’ Donuts) eliminated polystyrene coffee cups in May 2020. They estimate that this will remove one billion cups from the waste stream annually.

Sonic polystyrene cup found on ground
Littered Sonic polystyrene cup, photo by jnyemb on Flickr, Creative Commons license (CC BY 2.0)

The Role of Manufacturers

The manufacturers of polystyrene have an obvious interest in keeping it in use. But they argue against the environmental and human health problems stemming from it. They also promote recycling as a solution when it is not because of the volume. Corporations have the opportunity to do so much more than they do!

Case Study: Dart Container Corporation

Dart Container Corporation manufactures over 4,000 products including cups, plates, containers, lids, and straws for everyday use in restaurants, hospitals, schools, and homes. Their environmental commitment lists recycling polystyrene as one of their strategies, using what they collect at their plants and other drop-off facilities across the U.S. “We are the award-winning industry leader in creating and promoting recycling opportunities for EPS foam #6.”2 They sell it to manufacturers of picture frames, interior molding, pens, rulers, and foam packaging.

But they charge customers to collect polystyrene cups for recycling. They have a program called The Cups Are REcyclable (CARE), that offers Dart customers “an easy and affordable way to recycle foam food containers” for “Dart’s large-volume users, such as hospitals, universities and corporate cafeterias.” This provides educational materials, a collection bin, and a densifier (like a compactor) for a cost of $295 per month. The customer is responsible for the installation and maintenance of the machine, but Dart collects it once per month.3

Dart also has its Recycla-Pak program, a foam cup take-back program offered for sale by Dart distributors. Usually, companies cover the costs of take-back programs, not the customer. These are actually brilliant business models for Dart. They sell the single-use disposable cups, reclaim it at the same customer’s cost, and then resell the recycled products to new customers. Profit all around! But this isn’t the right thing to do and it inhibits recycling because of the cost.

Waffle House polystyrene cup, found next to the Tennessee River.
Waffle House polystyrene cup, found next to the Tennessee River. Photo by me

Bans on polystyrene

Many communities across the U.S. have instituted polystyrene bans, but it is a surprisingly controversial issue. There are those who recognize that we need to move away from polystyrene because of human health hazards and to curb pollution. Others think that replacement choices aren’t much better for the environment and that businesses will suffer from the higher cost of the replacements. I’ll explain a few of these bans.

Styrofoam cup and dead pelican
“Styrofoam cup and dead pelican,” photo by hikinghillman on Flickr, at La Ballona Creek in Venice Beach, California. Creative Commons license (CC BY-NC 2.0)

California

California has approximately 121 local municipal ordinances throughout the state banning polystyrene.4 Although there is not yet a state-wide ban in California, this shows how many citizens want to stop the use of polystyrene. Food containers are not recycled in California, “although the plastic industry has attempted to implement recycling programs that are simply way too expensive to be implemented in any meaningful way.”5 Besides impaired waterways littered with plastic and polystyrene trash, a 2004 report indicated that it was costing about $30 million per year to dispose of polystyrene materials.

In addition, in order to clear up confusion about customers using their own containers, the State of California passed Assembly Bill 619 in 2019. This new law now clearly allows the use of reusable food and beverage containers at restaurants and events in the state.6 I would love to see other states follow their lead so that this was allowed everywhere.

Maryland

Maryland was one of the first states to pass a polystyrene ban. “Environmentalists say the new law will have long-term benefits, removing a material made with fossil fuels, which contribute to climate change, and that clogs landfills, pollutes the Chesapeake Bay and other waterways and ultimately harms wildlife, people and the planet,” according to an article in the Baltimore Sun. But those against it say “alternatives to foam don’t always live up to their promises — plastic containers don’t get washed out and recycled or reused, and compostable ones aren’t always compostable without special equipment. Instead, they say, they end up in the same waste stream as the foam they replaced.”7

Maryland has not fully implemented the ban yet, as COVID-19 delayed the deadline for schools and restaurants to stop using polystyrene. Trash collection rose 22% in Baltimore during the pandemic, largely due to take-out packaging. It began October 1, 2020 and it will be exciting to see the long-term results.

“If researchers find the law helps improve Maryland’s waterways, that could help guide future policy around the world and “turn off the faucet” of supplying polystyrene into the water.”8

Other States

The call to reduce the use of polystyrene has been heard in other places as well. Maine passed a ban on polystyrene food and drink containers in supermarkets and restaurants which will go into effect in 2021. New Jersey has pursued a ban on single-use paper and plastic bags at supermarkets that will also limit the use of polystyrene takeout boxes and plastic straws. As of this writing, it is awaiting the Governor’s signature. These examples show that enough people in those states were concerned about the negative environmental impacts of polystyrene. They recognize that the best solution is to stop using it!

Polar Pop cup on the ground
Circle K Polar Pop cup made of polystyrene, found during a litter cleanup in downtown Chattanooga, Tennessee. Photo by me

Solution

While there are many alternatives, the best solution will always be to stop using single-use disposable products. It is my hope that polystyrene bans become the norm. Kate Breimann, state director of Environment Maryland, urges us to consider the larger issue of moving away “from the culture single-use” disposable items. She said implementing previous measures to protect the environment once loomed difficult as well, but have since paid off. “We think about when we had leaded gas and leaded paint, and people said, ‘It’s going to be hard for the industry,'” she said. “But now we have a healthier world.”9 This is absolutely true, and we all benefit from a healthier environment.

If you have ideas on how to end the use of polystyrene or single-use disposable take-out containers, please let me know in the comments below! As always, thanks for reading, and please subscribe!

 

Additional Resources:

Article, “Why Styrofoam (Expanded Polystyrene) Should Be Banned Everywhere In The World,” Jeff Lewis, medium.com, May 6, 2019.

Report, “Plastic Debris in the California Marine Ecosystem: A Summary of Current Research, Solution Efforts and Data Gaps,” California Ocean
Protection Council and California Ocean Science Trust, September 2011.

Series, “Quick Guide to my Packaging Industry Series,” becauseturtleseatplasticbags.com.

Footnotes:

Styrofoam and Polystyrene Containers are Poisoning Your Food, Part 3

Polystyrene food container from Popeye's, sitting on the bank of the Tennessee River.
Polystyrene food container from Popeyes, sitting on the bank of the Tennessee River. Photo by me

In Part 1 and Part 2 of this series, I told you about polystyrene (Styrofoam) food containers, how and what it they are made with, and how polystyrene is harmful and toxic to human health. Today I’ll explain its poor recyclability and its environmental impact.

“The irrefutable evidence and research has been mounting over decades from various federal agencies, city staff reports, state staff reports, environmental clubs, and nonprofits,” pertaining to the negative effects of Expanded Polystyrene (EPS). -Jeff Lewis, environmentalist writer1

Polystyrene container showing the #6 recycling symbol.
Polystyrene container showing the #6 recycling symbol. Photo by me

Recyclability

In practice, polystyrene food packaging is not recycled. Despite misconceptions, most municipalities do not accept it for recycling, even with the #6 recycling symbol. If it is collected, it often goes to the landfill instead of a recycling facility. Polystyrene is often contaminated with food residue which makes recycling impractical. Additionally, most establishments that use polystyrene food packaging do not provide separate recycling bins, so customers have no choice but to throw them in the regular trash. Nothing is recycled when it is thrown in the trash.

Overflowing trash receptacle at Dunkin Donuts
Photo by Chris Caravello on Flickr, Creative Commons license (CC BY 2.0)

Even when you do find a place that accepts polystyrene, there’s no guarantee that the meat trays and egg cartons that you wash, save, and cart back to the supermarket actually get recycled, if you’ll recall from Part 6 of my Packaging Series. Often, those collection sites are simply to draw you into the store and keep local recycling streams free from those materials.

“Styrofoam, despite the #6 plastic composition and the misleading recycling symbol it often carries, cannot be recycled easily or cost-effectively – less than 1% of Styrofoam is recycled in the USA.” -Green Dining Alliance of St. Louis

Cheaper to Produce New Polystyrene

Unfortunately, it is also easier and cheaper to produce new polystyrene than it is to collect, sort, and clean it for the recycling process. Thus, the market for recycled polystyrene is small and unlikely to grow. Companies such as BASF and Dart Container Corporation would have you believe otherwise. Both advocate for polystyrene recycling because they are producers of it as well. Many of the companies that do recycle polystyrene don’t accept food containers, they only accept polystyrene shipping materials. There are a few companies that do recycle used polystyrene food containers and have ways to clean them. But because food contamination makes food containers very costly to sort, clean, and recycle, those companies are rare.

New York City’s Department of Sanitation studied recycling polystyrene food containers and determined that recycling them is not economically feasible. “The report found that the majority of Styrofoam collected for recycling ended up in landfill anyway—but at a higher economic cost and carbon footprint compared to being directly landfilled.” This includes the cost of collection, recycling separation and contamination, and ultimately hauling it a second time to the landfill.2 The conclusion, as always, is to stop relying on recycling and focus on ending the use of single-use disposable items.

“The reason for the decline in price is that crude oil prices are so low that it is cheaper for companies to produce new Styrofoam products than to clean and reuse postconsumer products. This economic reality discourages other companies from getting into the market of recycling the polystyrene.” -Real Cost of Styrofoam3

The Volume of Polystyrene is Overwhelming

The sheer volume of discarded polystyrene is a problem as well. The world produces about 14 million tons of polystyrene annually. As with any type of plastic, we cannot recycle away the problem of single-use disposable items. We must stop it at the source; refusing to use them whenever possible.

Polystyrene cup left in the woods.
Image by Nik Stanbridge on Flickr, Creative Commons license (CC BY-NC-ND 2.0)

“25 billion Styrofoam coffee cups are used for just a few minutes and thrown away every year.” -Green Dining Alliance of St. Louis

Environmental Impacts

Since polystyrene is not recyclable, most of it goes to landfills and some inevitably makes its way into the environment. According to the Environmental Protection Agency (EPA), Styrofoam production is the fifth largest creator of toxic waste in the United States. Polystyrene products break down into smaller and smaller pieces and eventually become microplastics. Birds and marine life ingest small pieces because they mistake the pieces for food. Additionally, after the ingested polystyrene kills an animal, it can go on to kill again after that animal decomposes and the pieces reenter the environment.

“80% of Styrofoam ends up in landfills, and much of the remaining 20% in waterways.” -Green Dining Alliance of St. Louis

Polystyrene does not biodegrade, even the alleged biodegradable and compostable polystyrene, as I wrote about in Part 2 of my Packaging Series. Again, most take-out packaging is thrown away. Polystyrene foam litter is common as it is lightweight and breaks apart easily, making smaller pieces that become windswept. The Clean Water Action organization noted important facts about polystyrene’s environmental harm:4

      • Expanded polystyrene (EPS) products and their associated chemicals (such as styrenes) are widespread in the marine environment.
      • Polystyrene is in the digestive tracts of marine invertebrate and vertebrate wildlife.
      • Polystyrene is one of the most common types of debris on shorelines and beaches worldwide.
A large piece of a polystyrene container, found near the bank of the Tennessee River.
A large piece of a polystyrene container found near the bank of the Tennessee River. Photo by me

“Why is such a toxic material in use? Polystyrene is cheaper than some alternatives. However, the environmental expense of polystyrene far exceeds the cost restaurants and grocery stores are currently paying to provide them.” -Massachuesetts Sierra Club5

Solution

After considering the costs to human health, wildlife, and the environment, the solution is to end the use of polystyrene food packaging. Many reports have a similar conclusion and call for banning polystyrene or finding alternatives (see Additional Resources below). We must call for businesses to stop using these products and for local governments to ban their use. Moreover, we need to greatly reduce the amounts of all single-use disposable products we use. In my next article, I’ll explore alternatives to polystyrene food containers, the role of companies in their use of it, and municipal bans on polystyrene. Thank you for reading, and please subscribe!

 

Additional resources:

Video, “Plastic Recycling, Inc. recycles foam #6 from a MRF,” Plastic Recycling, Inc., March 25, 2016. This video shows the process for one of the rare companies that actually recycles polystyrene food packaging.

Article, “Now and forever: The Styrofoam dilemma,” by Catherine Solyom, Canwest News Service, Accessed October 20, 2020.

Report from cleanwateraction.org, “Greenhouse Gas Impacts
of Disposable vs Reusable Foodservice Products,” January 2017.

 

Footnotes:

Styrofoam and Polystyrene Containers are Poisoning Your Food, Part 2

Last updated on September 11, 2021.

Yellow warning sign with skull and crossbones
Image by OpenIcons from Pixabay

In Part 1 of this series, I introduced polystyrene, which we commonly refer to as Styrofoam, food packaging. This type of plastic is terrible for the environment and human health. Today, we’ll look at the toxicity of polystyrene in depth.

After watching friends and coworkers repeatedly reheat their take-out and leftovers in polystyrene, I decided to write a post about it. I had known polystyrene was potentially toxic for a long time, but I had no idea of the breadth of the problem.

Chemicals Leach from Containers into Food

Polystyrene leaches styrene and benzene, chemicals that have known toxic properties, into food. In testing, one scientific journal independently tested and found that polystyrene leaches more toxins when in contact with high-temperature contents and into foods with higher fat content.1 What does this mean? It means that if you buy hot food, fatty food, soup, or coffee and it is packaged in polystyrene, some of the chemicals from the container leach into your food. Over time, these chemicals can cause severe health problems.

“Styrene is likely to leach when it comes in contact with fatty foods, hot beverages, and especially alcohol. When thinking about the kinds of foods that typically end up in Styrofoam containers (fatty foods) and cups (hot coffee), it seems as though the exact kinds of items Styrofoam contains are exactly the kind of items it should never touch.” -The Green Dining Alliance2

Melted polystyrene spots from hot food in a polystyrene container.
I recently went to a BBQ restaurant in Dayton, TN. They serve most of their food in polystyrene containers. My fried okra side melted the polystyrene and those chemicals certainly leached into my food. I didn’t eat the okra, I dumped it out so that I could photograph the container. I likely will never dine at that place again. It really concerns me that people eat food out of these types of containers every day! Photo by me
Melted polystyrene spots from hot food in a polystyrene container.
Photo by me

Known Toxicity

When I searched “polystyrene human health” I got more than 13 million results. After reading many articles, I realized that all organizations and even the government, including the Environmental Protection Agency (EPA), know that polystyrene is harmful to human health as well as land and marine environments. Furthermore, the Food and Drug Administration (FDA) permits the migration of styrene from packaging into food!

Study after study shows that chemicals from polystyrene leach into foods and beverages, especially with higher temperatures and food with higher fat content. And study after study shows that styrene is dangerous to human health. In fact, most agencies caution against the use of polystyrene because of the known health hazards, including:

        • The Environmental Protection Agency (EPA)
        • The World Health Organization (WHO)
        • The International Agency for Research on Cancer
        • National Institute for Environmental Health Sciences
        • U.S. Department of Health and Human Services (DHHS)
        • National Research Council (NRC)
        • Occupational Safety and Health Administration (OSHA)
        • National Institute for Occupational Safety and Health
        • The Agency for Toxic Substances & Disease Registry (ATSDR), Center for Disease Control and Prevention (CDC)
Take-out in polystyrene containers
Image by albedo20 on Flickr, Creative Commons license (CC BY-NC-ND 2.0)

A Known Carcinogen

Styrene exposure increases the risk of leukemia and lymphoma and is a neurotoxin. This alone is enough reason to avoid polystyrene containers. In 2018, the World Health Organization (WHO) reclassified styrene as a probable carcinogen.3 While the EPA does not classify it as a carcinogen, it noted that animal cancer studies provided some evidence for carcinogenicity.4 Several of the organizations mentioned above, including the International Agency for Research on Cancer and the Department of Health and Human Services consider it to be carcinogenic.

Hormone Disruption

There are countless studies that show certain types of plastics contain known hormone disruptors. Those chemicals often mimic estrogen and they seep into food and beverages (including breastmilk). In 2014, Environmental Health tested 11 samples of polystyrene and consistently found estrogen seepage after exposure to intense steam or ultraviolet rays5. Since polystyrene is a type of plastic, this is just one more reason to avoid polystyrene containers.

It is terrifying that many schools use foam trays for cafeteria food. Hormone disruption in young children prevents them from developing normally, can affect their ability to reproduce as adults, and can set them up to be prone to other diseases.

Polystyrene food tray
Image by Laura Taylor on Flickr, Creative Commons license (CC BY-NC-ND 2.0)

Other Health Hazards

Styrene exposure can come from other sources, such as photocopier toner, automobile exhaust, and plastics manufacturing. Exposure can cause irritation of the skin, eyes, mucous membranes, the upper respiratory tract, and gastrointestinal irritation. Chronic exposure can cause neurological problems such as depression, headaches, fatigue, weakness, hearing loss, and disrupted kidney function.6

Additional Unknown Chemicals

There are many chemicals and ingredients that are not tested for and not regulated by the EPA and FDA. While this may seem surprising, the standard operating procedure in the United States is to allow the chemical to be used until a known hazard is not only discovered, but proven. Essentially, chemicals are innocent until proven guilty.

Hefty polystyrene container
Hefty polystyrene container, photo by me

Exposure through Manufacturing

Anyone who lives near or works in polystyrene manufacturing sites are at risk of even greater health problems due to respiratory exposure. The Clean Water Action organization noted that “occupational exposure to Styrene increases [the] risk of lymphoma, leukemia, lung tumors, pancreatic cancer, urinary bladder cancer, prostate cancer, and colorectal cancer. High rates of neurotoxicological effects have been reported in workers,” as well as decreased sperm counts.”7 These plants also emit a toxic and volatile gas called pentane, often used as a blowing agent in the production of polystyrene. 

“Over fifty chemical byproducts are released during the manufacturing of polystyrene, contaminating the air, water and communities that live near these facilities.” Children’s Environmental Health Network

What You Can Do

Polystyrene is toxic to human health. When ordering take-out, ask the restaurant if they use “Styrofoam” or polystyrene containers, and if they do, you can either ask if they have an alternative type of container or decide to order from somewhere else. When bringing leftovers home from a restaurant, keep a glass or metal container in your car specifically for such occasions. Bring your own reusable coffee mug to coffee shops. As I mentioned at the beginning of my post, please try to avoid eating food in polystyrene, and definitely stop reheating your food in polystyrene containers in the microwave

Last, polystyrene is the most common type of #6 plastic and is largely not recyclable because of food contamination. In Part 3, I will cover the problems with recycling and the environmental damage polystyrene causes. Thank you for reading, and please subscribe!

 

Additional Resources:

“Styrene,” Report on Carcinogens, 14th Edition, National Toxicology Program, Department of Health and Human Services.

Report, “What’s the Package? Unveiling the Toxic Secrets of Food and Beverage Packaging,” Clean Water Action and Clean Water Fund, August 2016.

Article, “Leaching of styrene and other aromatic compounds in drinking water from PS bottles,” by Maqbool Ahmad and Ahmad S. Bajahlan, Journal of Environmental Sciences, 19 (2007), p. 421–426, accessed September 12, 2021.

Footnotes: