Grocery store aisle, showing shelves of processed foods in colorful packages on the left and right, with dairy coolers at the back. — Photo by Franki Chamaki on Unsplash.

Food should never have a Proposition 65 warning on it. However, some foods do have these warnings, so we should avoid them. According to the Environmental Working Group (EWG), “more than 10,000 food additives are allowed for use in food sold in the U.S.” Many of these additives are preservatives, while others are used for color, shine, or stabilization of artificial flavors.¹

Following is a list of the types of substances to avoid. Remember, all the substances listed cause cancer, developmental problems in children, or reproductive issues.

Acrylamides

French fries on brown paper with a container of ketchup and parsley sprinkled across. — Photo by Pixzolo Photography on Unsplash.

Acrylamides form in french fries, potato chips, other fried and baked snack foods, roasted asparagus, canned sweet potatoes and pumpkin, canned black olives, roasted nuts, roasted grain-based coffee substitutes, prune juice, breakfast cereals, crackers, some cookies, bread crusts, and toast. It is a chemical formed during cooking or processing at high temperatures (frying, roasting, grilling, baking) since it converts sugars and other naturally occurring substances in these foods to acrylamide. Boiling and steaming foods do not create acrylamides.²

“When you fry or cook potatoes and certain other foods at high temps, a substance called acrylamide forms through a chemical reaction between the sugars and amino acids. An analysis of 32 studies found that among non-smokers, dietary acrylamide consumption was associated with an increase in endometrial and ovarian cancers. It’s what makes potato chips and french fries taste so damn good. But…is it worth the danger?” -Darin Olien, Fatal Conveniences³

Arsenic

Rice, rice cereal, some edible seaweeds, seafood, poultry, and mushrooms can absorb arsenic from the environment. According to the Food and Drug Administration, “arsenic levels are higher in certain soils and rocks and where arsenic-containing pesticides were once used on food crops or from the current use of those pesticides on non-food crops, and pollution from mining, fracking, and coal-fired power plants.”⁴ The World Health Organization (WHO) states that the main source of arsenic contamination is polluted groundwater used for drinking, crop irrigation, and food preparation.⁵ Chronic arsenic poisoning often leads to cancer.

BPA (Bisphenol A)

Blue tub of cans of Coca Cola, Diet Coke, and bottled water on ice. — Image by Kenny Holmes from Pixabay.

BPA (Bisphenol A) is a chemical that manufacturers use in plastic linings in cans (both the type for vegetables and beverages), jar lids, polycarbonate plastic bottles (#7 resin code), and bottle caps. It leaches into food. It is an endocrine disruptor and has been linked to developmental and health problems in children (such as Attention Deficit Hyperactive Disorder (ADHD)); anxiety and depression; early puberty in girls; diabetes; obesity; and heart disease.⁶

BHA (Butylated Hydroxyanisole)

Plate of charcuteries and cured meats such as salami and prosciutto, with cheese and pickled vegetables. Two silver forks at left. — Image by Gabriele from Pixabay.

BHA is a preservative used in cured and preserved meats and other foods. The substance is also found in certain rubber, plastics, and glues. Both the National Toxicology Program and the International Agency for Research on Cancer list it as a suspected carcinogen. Further, “the European Union classifies BHA as an endocrine disruptor because of its ability to lower testosterone and thyroid-hormone thyroxine.”⁷

BHT (Butylated Hydroxytoluene)

Red box of Cap'n Crunch cereal with the Captain eating a bowl of the cereal on the box design.

BHT is a preservative used in cereals like Cap’n Crunch and Apple Jacks. It causes hormone disruption and harms the reproductive system. The European Food Safety Authority indicated that it may disrupt endocrine function by causing thyroid changes and affecting development.⁸

Cadmium

Cadmium is in certain fish, shellfish, organ meats, mushrooms, oats, root crops, and some leafy vegetables grown in cadmium-rich soils.⁹ A study from 2023 found that age groups 6–24 months and 24–60 months old were the most exposed to cadmium in foods. “American infants and young children of these age groups who regularly consumed rice, spinach, oats, barley, potatoes, and wheat had mean [cadmium] exposures exceeding maximum tolerable intake level was set by the Agency for Toxic Substances and Disease Registry (ATSDR).”¹⁰ It can cause renal failure and is a human carcinogen.

Flame Retardants

Flame retardants, particularly PBDEs (Polybrominated Diphenyl Ethers), are known carcinogens that can also cause brain defects and hormone interference. These harmful chemicals are found in some farm-raised fish. Additionally, similar chemicals are used in certain ovenproof or microwavable plastic trays and plastic water bottles, which can lead to the leaching of chemicals into food and beverages. Several studies have documented the migration of chemicals from food packaging to food.

Lead

Theo Chocolate bar packaging — Many brands of chocolate, even organic, have high levels of lead and cadmium.

Lead is found in certain dietary supplements, balsamic vinegars, and imported spices such as turmeric and chili. Lead, along with cadmium, is also found in many types of chocolate. Exposure to lead is particularly harmful to children’s development, causing issues with hearing, speech, brain and nervous system damage, slowed growth, and learning and behavioral problems.¹¹

Mercury

Seafood counter, many types of seafood on a counter of ice. — Photo by Jonathan Noack on Unsplash.

Mercury is in many types of fish: king mackerel, shark, tilefish (from the Gulf of Mexico), swordfish, marlin, bigeye tuna, bluefin tuna, and orange roughy. Nearly all fish and shellfish contain traces of mercury, but the largest fish accumulate the most in their bodies. Mercury causes neurological and behavioral disorders such as tremors, insomnia, memory loss, neuromuscular effects, headaches, and cognitive and motor dysfunctions.¹² Refer to Monterey Bay Aquarium’s Seafood Watch for the safest seafood, linked under Additional Resources.

Phthalates

Phthalates are chemicals in plastics that can leach into food and beverages, especially when heated. They have been found in dairy products, meats, seafood, fruits and vegetables, and fast foods.¹³ Phthalates are hormone-disrupting chemicals that have been linked to many reproductive, developmental, and endocrine-related health problems.

PFAS (polyfluoroalkyl substances)

When waterways or environments are contaminated with PFAS, also known as “Forever Chemicals,” they can contaminate the food supply through plants and animals that are grown, raised, or processed in those polluted areas. Additionally, PFAS can migrate into foods through food packaging, certain types of take-out containers, food processing, and Teflon or nonstick cookware. This chemical family (PFAS, PFOA, PFC, etc.) can lead to issues such as altered metabolism and body weight regulation, increased risk of childhood obesity, reduced immune system function, and cancer.¹⁴

Potassium Bromate

Potassium bromate is added to the flour of many packaged noodles, baked goods, bread, tortillas, and other foods made with flour.¹⁵ It is a possible human carcinogen according to the International Agency for Research on Cancer. Multiple countries have banned it, including the United Kingdom, Canada, Brazil, and the European Union – but not the United States. The substance is also used in industrial cleaning agents, bombs, and photo-developing solutions.¹⁶

Propyl Parabens

Stack of flour tortillas on a cloth napkin, and a fork and spoon at left. — Image by Martin Diaz from Pixabay.

Propyl parabens are a preservative in processed foods like pastries and tortillas. But they’re also found in batteries, floor cleaner, and glue. When present in food, this chemical acts as an endocrine disruptor and can lead to developmental and reproductive harm.¹⁷

Styrene

Styrene and benzene from “Styrofoam” polystyrene take-out packaging can leach into food and beverages, especially with hot or reheated foods. Styrene is a known carcinogen and exposure increases the risk of leukemia and lymphoma and is a neurotoxin. Benzene is also a known carcinogen. Avoid take-out containers by bringing your own metal or glass leftover containers.

Synthetic Food Dyes

Caucasian person's hand holding a red bag of Skittles. — Photo by Jonathan J. Castellon on Unsplash.

Manufacturers use synthetic food dyes in many foods and beverages. And especially candy! But these same colorants are also used in household cleaners, wood stains, pesticides, and even blue jeans. While not all food dyes are toxic and not all are on the Proposition 65 list, we know that certain dyes are carcinogenic. Others affect development and cause behavioral difficulties in children.¹⁸

Avoid Toxic Ingredients

Avoid the ingredients listed above, as they are the most toxic. If any food has a Proposition 65 warning, either put it back on the shelf or return it. No food should contain that type of warning.

Remember to avoid processed food as much as possible. Try to limit your consumption of seafood and meat, and minimize your use of food packaging. Processed foods include crackers, bread, canned goods, frozen or packaged meals, cereal, etc. In general, the less processed the food, the better it is for you. Always check the ingredients list. If it contains a chemical-sounding word or something you can’t pronounce, it’s best to avoid eating it.

I hope this helps! Thank you for reading, please share and subscribe!

“It’s better to pay the grocer than the doctor. And smarter to trust the farmer than the pharmacist.” -Darin Olien, Fatal Conveniences¹⁹

Additional Resource:

Website, Monterey Bay Aquarium Seafood Watch.

Footnotes:

Article, “Common food additives in Cap’n Crunch and Apple Jacks cereal may harm human health,” ewg.org, October 6, 2021. ↩︎
Page, “Acrylamide,” Proposition 65 website, Updated February 2019. ↩︎
Book, Fatal Conveniences: The Toxic Products and Harmful Habits That Are Making You Sick―and the Simple Changes That Will Save Your Health, by Darin Olien, Harper, New York, 2023. ↩︎
Page, “Arsenic in Food,” Food and Drug Administration, accessed September 16, 2024. ↩︎
Page, “Arsenic,” World Health Organization, December 7, 2022. ↩︎
Page, “Bisphenol-A (BPA)/Bisfenol A (el BPA),” Columbia University Mailman School of Public Health, accessed September 16, 2024. ↩︎
Article, “Common food additives in Cap’n Crunch and Apple Jacks cereal may harm human health,” ewg.org, October 6, 2021. ↩︎
Article, “Common food additives in Cap’n Crunch and Apple Jacks cereal may harm human health,” ewg.org, October 6, 2021. ↩︎
Page, “Foods,” Proposition 65 website, May 2021. ↩︎
Article, “Dietary exposure to cadmium from six common foods in the United States,” Food and Chemical Toxicology, Volume 178, August 2023. ↩︎
Page, “Lead Exposure Symptoms and Complications,” Centers for Disease Control and Prevention, April 10, 2024. ↩︎
Fact Sheet, “Mercury and health,” World Health Organization, March 31, 2017. ↩︎
Page, “Phthalates,” toxicfreefuture.org, accessed September 19, 2024. ↩︎
Page, “Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS),” National Institute of Environmental Health Sciences, update September 3, 2024. ↩︎
Page, “This cancer-causing chemical may be lurking in your bread,” ewg.org, May 4, 2022. ↩︎
Article, “From baguettes to bombs: Surprising industrial uses of common food chemicals,” ewg.org, June 6, 2024. ↩︎
Article, “From baguettes to bombs: Surprising industrial uses of common food chemicals,” ewg.org, June 6, 2024. ↩︎
Article, “From baguettes to bombs: Surprising industrial uses of common food chemicals,” ewg.org, June 6, 2024. ↩︎
Book, Fatal Conveniences: The Toxic Products and Harmful Habits That Are Making You Sick―and the Simple Changes That Will Save Your Health, by Darin Olien, Harper, New York, 2023. ↩︎

Last updated on May 2, 2023.

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 an article about it. I had known polystyrene was potentially toxic for a long time, but I had no idea just how toxic it is.

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 That 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
I recently went to a BBQ restaurant in Dayton, TN. They serve most of their food in polystyrene containers. My fried okra 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 Marie Cullis.
Photo by Marie Cullis.

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 U.S. 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 these:

- - - 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)

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 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 rays.⁵ 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 a chemical to be used until a known hazard is not only discovered, but proven. Essentially, chemicals are innocent until proven guilty.

Hefty polystyrene container, photo by Marie Cullis.

Exposure through Manufacturing

Anyone who lives near or works in polystyrene manufacturing sites is 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 Network⁸

What You Can Do

Polystyrene is toxic to human health. When ordering take-out, ask the restaurant if they use “Styrofoam” or polystyrene containers. If they do, you can ask if they have an alternative type of container or you can 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 article, 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 share and 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.