BPA-free plastics may still pose health risks because they often contain other structurally similar chemicals.

Used since the 1940s, 'forever chemicals' include thousands of different types of substances routinely integrated into industry and consumer products, yet research suggests they can accumulate in the body over time.

Learn about the seven types of plastic, including their recyclability, toxicity, health risks, and common uses.

Watch 'Last Week Tonight' explore the risks of 'forever chemicals,' a group of human-made chemicals used in everyday products to make them resistant to water, stains, grease, and heat. (Warning: language.)

Per- and polyfluoroalkyl substances (PFAS) are a group of human-made chemicals used in a wide range of products due to their unique properties. However, because they can persist in the body and environment for thousands of years, they've earned the moniker "forever chemicals"—and have been linked with numerous health risks.

Most of the 86,000 consumer chemicals registered with the US EPA have never received rigorous toxicity testing, though not all those are still in current use.

Nanoplastics can bypass the blood-brain barrier and may harm the nervous system

Nanoplastics are formed from the breakdown of microplastics and can breach cells. Their large surface area relative to size allows them to carry higher concentrations of forever chemicals than the surrounding environment into sensitive organs.

Stainless steel and cast-iron pans should be used over older nonstick cookware

Although modern nonstick pans avoid forever chemicals like PFOA, they were previously used in the manufacturing of Teflon coatings and have been linked with certain types of cancer, infertility, and other adverse health outcomes. Vintage plastic utensils should also be avoided due to the leeching of contaminants in early formulations of plastic.

Microplastics are infiltrating the human body with unclear but concerning effects

Scientists have linked microplastics to immune system damage, hormone disruption, inflammatory diseases, and even cancer—yet most of their health impacts remain unknown due to limited research. Studies suggest we ingest about a credit card's worth of plastic weekly.

Forever chemicals are so common that experts concluded in 2022 that it's uncertain whether limiting consumer exposure would truly reduce one's exposure to these substances, and noted it would still take years for the body to clear them.

The amount of plastic chemicals in 300 everyday Bay Area foods

Food production is more complicated than it appears, and manufacturing, packaging, and shipping processes can add significant substances to your food. This massive project compiled data on 300 samples of foods delivered to the San Francisco area, testing for the presence of 18 different kind of plastic. Learn how to read the data here with its helpful guides and then explore the table yourself.

Why bacterial bioremediation may help counter the negative effects of past chemical solutions

Molecules such as DDT, a synthetic insecticide, and PFAS—"forever" chemicals used to make products resistant to heat, water, and grease—have historically been used across various industries but are now known to be harmful. Microbes that can convert some of these substances into nontoxic products, such as water and carbon dioxide, have already been identified, with ongoing research to find others.

Most biodegradable plastics don’t break down in everyday conditions

Despite their eco-friendly name, biodegradable plastics often require industrial composting, which most areas lack, to decompose the uncommon compounds found in them. This means they may linger in landfills or contaminate conventional plastics in recycling bins.

The FDA claims microplastics have not yet been shown to pose a health risk

Although microplastics and nanoplastics are found in many foods and environments, their presence does not violate regulations. Additionally, as of 2025, the administration believes evidence does not confirm that detected levels harm humans.

See this interactive global map that highlights which forever chemicals have been detected in specific wildlife species, providing data on hundreds of species exposed to these hard-to-breakdown substances.

The US FDA issued a 2025 warning about BPC-157 and other popular peptides that are marketed for various regenerative properties.

Microplastics have been identified across human body systems, with research finding they are most commonly ingested through inhalation, drinking water, and diet before crossing barriers into organs.

Forever chemicals accumulate up the food web, with recent research indicating that apex predators have higher concentrations because they're eating prey that also have accumulated the substances.

The five most common chemicals found in modern food

Most modern processed foods rely on a number of preservatives to stay fresh from production to our plates. The most common include citric acid (preservative and flavor), sodium benzoate (preservative), xanthan gum (thickening and stabilizing), carrageenan (thickening), and red dyes 3 and 4 (for color).

Research shows that over 1,000 metric tons of microplastics fall on national parks every year—equivalent to 120 million bottles of water.

Teflon was an accidental discovery by a DuPont scientist in the 1930s resulting from efforts to create a safe refrigerant.

Arteries with microplastic deposits linked to higher risk of cardiovascular events

Research shows that microplastics and nanoplastics can accumulate in major arteries, and patients with these deposits are significantly more likely to suffer heart attacks, strokes, or death. These deposits are possible due to these particles' ability to cross blood barriers.

A guide to single-use plastic bans across the US

Over 100 cities and municipalities in the US have banned Expanded Polystyrene (EPS) in government facilities including New York City, Los Angeles, Seattle, San Diego and Miami Beach, Florida. Here, maps illustrate what US states have bans in place.

The history of natural and synthetic plastics

From cheap toys to woolly jumpers, plastic can be found in more products than many people realize. From a chemist's perspective all these things are made of the same class of materials: Polymers. And the distinction between which ones we happen to call "plastics" and which ones we don't is fairly arbitrary.

Microplastics have been found everywhere there is liquid or vapor water, from the oceans and tropical waters to polar ice and the air we breathe, posing growing risks to wildlife and ecosystems.

Ultraprocessed foods include preservatives, dyes, sweeteners, and more

Processed foods are those that have been altered from their original state, which includes numerous processes that we consider natural, such as cooking or salting. Ultraprocessed foods contain at least one item that wouldn’t be found in a kitchen, like hydrogenated oils or high-fructose corn syrup. It’s estimated that nearly 75% of all foods consumed in the US are ultraprocessed, though that doesn’t mean that all of them are unhealthy. In fact, some, such as prepackaged whole wheat bread and soy milk, are recognized for their health benefits.

A remote Scottish island is awash in forever chemicals even though there are no obvious industrial sources nearby, and scientists suspect the toxic substances are accumulating via seaspray.

The prevalence of microplastics came from plastic’s affordability and versatility

Microplastics' durability and overuse have led to massive pollution that overwhelms the planet's ecosystems. Avian, terrestrial, and marine life have been observed to contain microplastics in their bodies, but reverting to paper, cotton, and other materials in manufacturing also brings environmental challenges.

More than 130 nations have enacted bans or restrictions on plastic items

Several US states have enacted similar restrictions on plastic bags, straws, food containers, and other single-use plastics, while others have prohibited plastic bans. Despite this, California’s plastic bag ban cut usage by more than 70%, showing the potential of these policies.

BPC-157 stands for Body Protection Compound-157.

A comprehensive review of BPC-157 studies identified no human safety data

This meta-analysis included available studies on this peptide from 1993-2024, and identified 36 studies. It found 35 preclinical (nonhuman) studies and one retrospective study in humans of musculoskeletal pain following injections of BPC-157 for unspecified chronic knee pain. In that one human study, 7 of 12 patients receiving BPC-157 reported relief after the injections (though many had injuries that often heal on their own over time).

The global plastic crisis in images

For decades we have relied on plastics to keep us safe, insulate our homes, and make sure our food stays fresh. But when does plastic’s life come to an end?

Microplastics 101: What we know about the contaminants invading our bodies

Fifty-one trillion particles of microplastics float in our oceans. Yet there is very little science of how this affects our health. This quick 2-minute video explains the dangers of microplastics.

Here's how the seven types of plastics fare in the recycling process

To help you make better-informed decisions about the products that you buy, here's a simple explanation of the seven different types of plastic, how they differ, and their impact on the environment.

Microplastics are entering human food chains through carrots, wheat, and other foodstuffs grown in farmlands fertilized by sewage sludge.

Pollution from lead battery recycling has led to widespread contamination

Many small-scale operations worldwide remain unregulated, bypassing environmental regulations and causing increasing health threats, primarily to children. A 2020 report by UNICEF found that one-third of the world's children are being poisoned by lead from recycled batteries, among other sources.

Artificial sweeteners are considered safe for most people, but researchers are investigating their effects on gut microbiome health.

How disruptions in oil markets can drive up the price of everyday goods

Most types of plastic are made from polymers derived from chemicals produced by the processing and refining of crude oil and natural gas. Spikes in the cost of either fossil fuel raise the cost of wrappings, tubs, and other plastic containers for products.

Food companies are exploring 'GLP-1 friendly' diet labels

Producers of foods like Healthy Choice frozen meals are placing "GLP-1 friendly" labels on their food, but there's no regulation about what that label means. Nutritionists say that GLP-1s can help reduce appetite, but healthy, balanced diets are a necessary complement to the medications. Data shows that about half of GLP-1 users quit these medications within a year and then rapidly regain weight, underscoring the importance of also prioritizing healthy eating.

Many chemicals used in fracking fluid have been classified as toxic

Although the fluid has been known to leach into drinking water supplies, raising health concerns, fracking is exempt from federal clean water regulations due to a loophole in the Energy Policy Act of 2005 championed by former US Vice President Dick Cheney.