"Forever chemicals" are toxic, they're everywhere, and they don't break down. The problem can be solved, though, according to health experts and scientists, if the government bans the substances in household products.

On Tuesday, the US Environmental Protection Agency proposed strict limits on six per- and polyfluoroalkyl substances (PFAS) in drinking water.

It's the first time the government has moved to regulate PFAS, a class of thousands of chemicals used in everything from dental floss and toilet paper, to common furniture treatments and food packaging.

PFAS, aka "forever chemicals," take many years to leave the human body, which is a major problem since they're linked to multiple cancers, thyroid disease, liver damage, decreased fertility, asthma, allergies, and reduced vaccine response in children.

The chemicals are prolific in everyday human environments – in our water, food, air, and even the dust in our homes.

EPA's proposal to limit PFAS in drinking water is headed in the right direction, but it only addresses one source of day-to-day exposure.

"I think it's a great first step forward," Elsie Sunderland, a professor of environmental chemistry who leads environmental contaminants research at Harvard, told Insider.

But we still have a long way to go.

Given the enormity of the problem, the EPA's proposal for drinking water "just doesn't go far enough," Carmen Messerlian, a professor of reproductive environmental epidemiology at Harvard's TH Chan School of Public Health, told Insider.

"The government needs to hold these companies strictly accountable at the highest level possible and say, 'No more PFAS, we're banning them'," said Messerlian, who studies PFAS' impacts on reproductive health.

The hazards of PFAS production

PFAS have been detected in Antarctica, Arctic sea ice, on Mount Everest, throughout the oceans, and in rainwater and soil across the planet.

While PFAS are linked to a slew of diseases and conditions, the chemicals may not cause everyone to develop health issues, but they increase the risk that some people will.

"There's probably a lot more impact. We just haven't been able to do the science to be able to show it," Messerlian said.

Last year the EPA assessed the published science, to establish a baseline for future regulations: What level of certain PFAS in drinking water would cause no health impacts, even for especially vulnerable people?

For PFOA, the agency determined that the safe quantity in drinking water was 0.004 parts per trillion (ppt), and for PFOS, it was 0.02 ppt.

Those are below the levels that modern labs can reliably detect. So essentially, in EPA's eyes, a safe level of those two PFAS chemicals is zero.

The regulations proposed on Tuesday are two orders of magnitude higher than those ideal-world guidelines, at 4 ppt for both PFOA and PFOS. This is at least a level at which labs can reliably detect the substances, according to the EPA.

Filtration systems can remove those chemicals from drinking water to meet these new rules, but that doesn't stop all the PFAS entering your body through food, furniture, and clothing.

"You can't just regulate in drinking water, without addressing the other side," Sunderland said, referring to the countless US companies selling products full of PFAS.

It's worth noting that PFOA and PFOS have been phased out of production in the US since the 2000s. But thousands of other PFAS are still being manufactured. That means more and more of them are getting into the environment – and drinking water – every day.

Ban forever chemicals to 'turn off the tap'

The next big step for the US government should be getting PFAS out of household goods that don't need it – especially materials that touch food, experts told Insider.

"Obviously, you want to stop the tap, turn off the tap," Ian Cousins, an environmental chemist who studies PFAS at the University of Stockholm, told Insider.

The European Union has already proposed a ban on 10,000 PFAS. Cousins said it would make sense to do so in the US as well, though some "necessary uses" of PFAS may continue, such as in electrical wiring or for medical devices.

Most likely, some PFAS are not toxic, but a precautionary approach would treat them all as hazardous until they can be proven safe.

"In the future, we might want to start thinking about regulating them as a class," Sunderland said.

The root of the problem is a fatal flaw in US regulation

Even if the government completely cuts off and cleans up PFAS, this will happen again with other chemicals if we don't solve a larger issue, Sunderland said.

The root of the problem is that US regulation does not require that new chemicals be thoroughly vetted for safety or human-health hazards.

Chemicals manufacturers are "innocent until proven guilty," Sunderland said, and the burden of proof falls on communities suing those companies over health issues they suspect were caused by new chemicals.

Until that system changes, manufacturers can just keep inventing new compounds with unknown effects on the human body.

At the very least, Messerlian said, companies should be required to disclose what's in their products so that consumers can make educated decisions.

"Can I stop myself from using everything under the sun that has PFAS in it? It'd be very, very hard. Even for someone who's an expert in this area like myself," she said.

"What we need is, first and foremost, top-down approaches that actually hold these companies strictly accountable for what they're putting in our bodies."

This article was originally published by Business Insider.

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