Alicia Silverstone is warning her fans about the supposed dangers of toilet paper.

On Sunday, the "Clueless" star, 47, shared on TikTok a commercial she produced and starred in for PlantPaper, which sells toilet paper made entirely of bamboo, according to the company's website. In the commercial, Silverstone claims regular toilet paper "is contributing to your risk of cancer" by containing chemicals collectively known as PFAS.

The actress says these chemicals "never break down," "never leave your body" and contribute to a host of problems including hemorrhoids, urinary tract infections, chronic inflammation and vulvovaginitis, or an inflammation or infection of the vagina.

"OK, so it might cost like $15 more per year," Silverstone says of PlantPaper's toilet paper. "That's the cheapest investment in your health that I can imagine." One order of 16 rolls of PlantPaper toilet paper costs $42, per the company's website.

So what's the truth? Should people be concerned about PFAS in toilet paper? Here's what experts say.

What are PFAS?

Perfluoroalkyl and polyfluoroalkyl chemicals, collectively known as PFAS, consist of more than 12,000 man-made chemical compounds that are "used in a broad array of consumer products," Susie Dai, an environmental scientist at Texas A&M University, previously told USA TODAY.

Most commonly, PFAS are used in non-stick, greaseproof and waterproof coatings and surfaces, and are also used in flame retardants and to extend the life or usefulness of a variety of everyday items.

What are PFAS?'Forever chemicals' are common and dangerous.

Are PFAS the same as 'forever' chemicals?

While different PFAS have different chemical structures, all PFAS have at least one common trait: the presence of carbon-fluorine bonds, which are among the strongest bonds in chemistry. 

This powerful bond is attractive to manufacturers because it extends the life and improves the functionality of many common products; but it's also a bad thing, because it means that once these chemicals are created and released into the world, they don't break down easily in the environment or in our bodies − earning PFAS the nickname "forever chemicals."

Over time, this exposure can do harm to the planet as well as to people and animals. "Exposure to high levels of PFAS is associated with higher risk of cancer, impaired kidney and liver function, reproduction and embryonic development issues, and blunted responses to vaccines," Dr. Kristin Scheible, a microbiologist and immunologist at the University of Rochester Medical Center, previously told USA TODAY.

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So should people be worried about PFAS in toilet paper?

PFAS are indeed in toilet paper, per the American Chemical Society; however, not all exposure to PFAS is necessarily dangerous − and this is true of the PFAS in toilet paper.

While Silverstone is right that, yes, many common toilet paper brands do contain PFAS, Erin Haynes, a professor of preventative medicine and environmental health at the University of Kentucky, says the risk of exposure to PFAS via toilet paper is not high enough to warrant concern.

This is because dermal exposure to PFAS − or, the rate at which these chemicals get absorbed through skin − is very minimal. A greater risk, she says, is ingesting PFAS via food or water.

"The toilet paper, clothing, anything would have to be on the skin long enough to let absorption occur," Haynes says. "I don't think the absorption rates or the time spent on the body substantiate the claim."

Still, she says, if someone's chief concern with normal toilet paper is its effect on the environment, then bamboo toilet paper might be a better option for that reason.

How are people exposed to PFAS?

Avoiding exposure entirely is difficult, since PFAS have been used in manufacturing for more than 80 years and have found their way into countless soil and water sources during that time; however, it's possible to at least limit someexposure by knowing where PFAS are commonly found.

For instance, PFAS are commonly used in non-stick cookware, greaseproof food packaging, outdoor clothing, waterproof cosmetics, and stain-resistant carpets and furniture. While most such products don't advertise that they were made using PFAS, if a product says it's waterproof, stain proof or non-sticking − and isn't advertised as being PFAS-free − "then it likely contains PFAS," Scott Bartell, a professor of environmental and occupational health at the University of California, Irvine, previously told USA TODAY.

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Beyond commercial product use, people are also exposed to PFAS by eating produce that has been grown in PFAS-contaminated soil or by eating animals that have fed on PFAS-contaminated grasses. More commonly, many people drink directly from PFAS-contaminated water sources, as research shows that as much as 45% of tap water in America has become contaminated by at least one of these forever chemicals.

What can help is installing a water purification system for any tap water that enters the home so PFAS can be filtered out, "until the new EPA standards begin to take effect," Bartell previously told USA TODAY.

Contributing: Daryl Austin, USA TODAY