What’s the Difference Among Microplastics, Phthalates, BPA, and PFAS?

Here's why these potentially toxic materials are concerning and where we encounter them in everyday life

By Kevin Loria

May 29, 2024

Four blobs of color representing PFAs, Microplastics, Phthalates, and BPAs cover an illustrated house.

Synthetic chemicals are everywhere—including in the food we eat, the water we drink, the products we use, the dust on our floors, and the air that we breathe.

Over the years, Consumer Reports has investigated many of these potential hazards in a variety of foods and products. We’ve identified per- and poly-fluoroalkyl substances (PFAS) in milk, cookware, and food packaging, and BPA and phthalates in packaged supermarket and fast-food products. We’ve also written about the microplastics all around us.

With all these acronyms, it’s not surprising that many readers may be confused about what these substances are and what risks they pose.

"We want to make sure that consumers understand the differences among these contaminants that can sometimes be found in combination with each other in our food," says James Rogers, PhD, head of food safety testing at CR.

With that in mind, here’s our guide to what these various substances are, how they are used or end up in and around us, and why they’re concerning.

In this article

Microplastics

What they are: Most of the substances discussed below are chemicals that can be used in plastics or in other products to impart flexibility, rigidity, durability, resistance to water and grease, or some other quality. Microplastics and nanoplastics are different. These terms are used to refer not to any particular chemical but to tiny bits of plastic, which may be made from a wide variety of chemicals.

They range in size from the small but visible to completely microscopic. The term microplastic typically refers to fragments 5 millimeters or smaller; particles smaller than 1 micrometer (1,000 nanometers, or 0.001 mm) are generally referred to as nanoplastics.

Where they are used: Microplastics have been intentionally added to a number of products, including artificial turf, cosmetics, fertilizers, and detergents. Some of these uses have been curtailed in recent years: For example, they have not been allowed to be used as abrasives in toothpastes and face washes in the U.S. since 2015. And in 2023, the European Union banned intentionally adding microplastics to all products, though some are allowed to stay on the market through 2035.

But microplastics don’t have to be intentionally added to products to make their way into food, water, air, and the environment. Many of the microplastics and nanoplastics we encounter are fragments that break off of other products as they wear down over time. A few common sources include synthetic rubber tires, clothing and other textiles made from synthetic materials, and plastic bags and plastic containers used for food and drink.

All plastic breaks down over time into smaller fragments, and these fragments spread further and further—to the point that they can be found in Arctic snow, seemingly pristine Hawaiian beaches, and inside the blood and tissues of many people around the world.

Why they’re concerning: Despite increasing concerns about plastic pollution, its use in products is actually still on the rise. And there’s growing evidence that having tiny fragments of plastic in our blood or body tissue may be harmful. Some research has linked the presence of microplastics in blood vessels to cardiovascular disease. Microplastics in the colon have been linked to bowel disorders. And there’s even evidence that tiny fragments of plastic can cross important barriers in the body, including the placenta and blood-brain barriers, meaning these fragments could affect newborns and cross into our brains.

Some of the health harms of these particles could be because their physical presence in our bodies could cause inflammation, which itself can increase the risk of many issues such as cardiovascular disease and colorectal cancer. But there are also two chemical concerns with microplastics. First, because plastics are made of chemicals, including some that we know can harm human health—more on those below—microplastics could serve as vehicles that help carry those chemicals into us, increasing our overall exposure. Second, researchers have found that other hazardous contaminants in the environment frequently adhere to and accumulate on microplastics. These include pesticides; polycyclic aromatic hydrocarbons (PAHs), which can be generated in wildfire smoke; and PCBs, which were banned long ago because of their highly carcinogenic properties but are still persistent in the environment.

Phthalates

What they are: The term phthalates refers to a group of chemicals often used as plasticizers, substances intentionally added to some plastics to make them more flexible and durable. There are a number of different phthalates in use—DEHP is one of the more widely known ones—as well as phthalate-replacement chemicals, which share many of the same properties. These chemicals are not microplastics, though phthalates might be found in those fragments or adhered to them.

Where they are used: Phthalates are used in hundreds of different products. You can find them in vinyl flooring, lubricating oils, garden hoses, shower curtains, and medical tubing. They’re also used in some cosmetics and personal care products, like soap, shampoos, and hair sprays to, for example, make nail polish stronger and soaps lather more, and as a solvent or stabilizer in fragrances.

Some uses have been restricted in recent years. For example, certain phthalates are no longer allowed in children’s toys and child care items like pacifiers and baby bottles, and some are no longer used for food contact applications—though at least nine commercially used phthalates are still authorized for food contact.

Why they’re concerning: Phthalates have been so widely used for so long that they are ubiquitous, and researchers from the Centers for Disease Control and Prevention have detected measurable levels of many phthalates in the vast majority of people tested in the U.S.

While more research is needed, a number of phthalates have been shown to be endocrine-disrupting chemicals: By mimicking the effects of hormones, they can disrupt some of the many functions hormones have in the body.

Exposure to some phthalates has been associated with changes to reproductive health, for example, with studies showing links to diminished sperm counts, preterm births, and uterine fibroids. One of the better studied phthalates, DEHP, has been linked to insulin resistance, high blood pressure, and early menopause, along with reproductive issues. When CR tested packaged foods in 2023, this was the most common phthalate we detected, at levels higher than those that researchers have linked to health problems.

And while phthalate-replacement chemicals may be becoming more common, it’s possible that these too could be linked to health problems, according to Tunde Akinleye, a CR chemist who oversaw CR’s testing of packaged foods. Because the use of these chemicals in the plastic industry is relatively new, the potential health effects from exposure haven’t been as extensively studied as they have with phthalates.

Scientists who study the endocrine system say that endocrine disruptors, or EDCs, don’t cause harm in the same way that traditional toxins do. With a traditional toxin such as arsenic, the dose makes the poison, and higher doses tend to have stronger effects than lower doses. But because our bodies are so sensitive to the effects of hormones, even very low doses of EDCs can have significant effects—and the effects at those low doses are not always the same as the effects seen at higher doses. Because of this, these researchers say it’s especially important to be aware of the effects of EDCs on kids, whose bodies are still developing.

Illustrations of places BPAs are located: water, air, food (fish), dust, canned food, plastic storage containers

BPA and Other Bisphenols

What they are: Bisphenol-A (BPA) is the best-known member of a family of chemicals called bisphenols. BPA and related chemicals, like BPS or BPF, are used to make certain types of hard plastics and resins.

Where they are used: These chemicals are used to make polycarbonate plastics, which tend to be hard, and are used in products like water bottles, storage containers, eyeglass lenses, computers and other electronics, and sports safety equipment. These chemicals are also used to create epoxy resins that line the inside of water pipes, bottle tops, and food and drink cans.

Why they’re concerning: As with phthalates, bisphenols are so widely used that CDC researchers have determined they’re in the blood of nearly all Americans.

Also like phthalates, BPA and other bisphenols appear to be endocrine disrupting chemicals. BPA is known to act like estrogen in the body, and it can affect reproduction, metabolism, and behavior. The American Academy of Pediatrics has said that in kids, it can change the timing of puberty, increase body fat, decrease fertility, and affect the nervous and immune systems.

If you look for a plastic water bottle, baby bottle, or similar product now, you may see some advertised as “BPA-free.” But in many cases, it’s likely that instead of BPA, manufacturers could have used one of the many other available bisphenols to serve the same function. And it’s very possible that these substitutes could cause the same health effects, Philip Landrigan, MD, a pediatrician and the director of the Program for Global Public Health and the Common Good at Boston College, has told Consumer Reports.

PFAS

What they are: The term PFAS refers to a huge family of chemicals that all rely on the incredibly strong bond that can form between carbon and fluorine atoms. There are thousands of chemicals in this family. Some of the better-known ones are PFOA, PFOS, GenX, PTFE (commonly known as Teflon), and 6:2 FTS.

These chemicals are often referred to as “forever chemicals” because of that unusually strong carbon-fluorine bond. Once these are made, they are very difficult to destroy and could persist in the environment essentially indefinitely.

Unlike the other chemicals and particles discussed above, PFAS don’t necessarily have anything to do with plastic. They have been added to and can be found in some plastic products, but they’re also frequently added to products made of paper, cardboard, cloth, or metal.

Where they are used: PFAS can make products waterproof, stain-resistant, grease-proof, nonstick, and resistant to heat or corrosion. Because of that, they’ve been used to make grease-proof food packaging, nonstick pans, water- and stain-resistant clothing and furniture, easy gliding dental floss, firefighting foam, and more.

In the U.S., PFOA and PFOS are no longer manufactured. But CR’s tests have found these in a number of products, including food packaging and milk. This could be for a number of reasons: Manufacturers could still be using these unknowingly, materials produced overseas may contain them, or they persist in the environment long after they are phased out. Plus, under certain conditions, alternative PFAS may break down and re-form as these compounds.

In February, the FDA announced that PFAS will no longer be used to create grease-proof coatings for food packaging, though it may take until June 2025 before products with those coatings are off the market. And on April 10, the Environmental Protection Agency announced nationwide limits on certain PFAs in drinking water for the first time ever. These limits are far stricter than the unenforceable action levels previously in place, and the agency estimates that 6 to 10 percent of water utilities will need to take action to remediate PFAS contamination.

Why they’re concerning: Because of their incredible persistence, these chemicals build up in the environment, especially where they are produced, used, or disposed of.

And they’ve been linked to a growing list of health issues. PFAS exposure has been linked to impaired immune system response, thyroid disease, higher cholesterol levels, various cancers, metabolic changes, liver damage, and kidney disease.

They’re also really hard to avoid. That’s partially because they’ve been so widely used that they’ve contaminated water and food supplies, so even if you don’t cook with a nonstick pan, you probably have them in your kitchen: They could be in some of your foods, or on paper or other products. But it’s also because the wide array of names for these products make confusion easy to come by. Some products will be advertised as having no PFOA or PFOS but still contain other unlabeled PFAS, like PTFE.

Kevin Loria

Kevin Loria is a senior reporter covering health and science at Consumer Reports. He has been with CR since 2018, covering environmental health, food safety, infectious disease, fitness, and more. Previously, Kevin was a correspondent covering health, science, and the environment at Business Insider. Kevin lives in Washington, D.C., with his wife and children. Follow him on Twitter @kevloria.