Many of the world’s plastic containers and bottles are contaminated with toxic PFAS, and new data suggests that it’s probably leaching into food, drinks, personal care products, pharmaceuticals, cleaning products and other items at potentially high levels.

It’s difficult to say with precision how many plastic containers are contaminated and what it means for consumers’ health because regulators and industry have done very little testing or tracking until this year, when the Environmental Protection Agency discovered that the chemicals were leaching into a mosquito pesticide. One US plastic company reported “fluorinating” – or effectively adding PFAS to – 300m containers in 2011.

But public health advocates say new revelations suggest that the compounds are much more ubiquitous than previously thought, and fluorinated plastic containers, especially those used with food, probably represent a major new exposure point to PFAS.

“Fluorination is being used for plastic food containers, cosmetic containers – it’s in everything,” said Tom Neltner, a senior scientist with the Environmental Defense Fund. “It is disturbing.”

PFAS, or per- and polyfluoroalkyl substances, are a class of about 9,000 compounds that are used to make products like clothing and carpeting resistant to water, stains and heat. They are called “forever chemicals” because they do not naturally break down and can accumulate in humans.

The chemicals are linked to cancer, birth defects, liver disease, thyroid disease, plummeting sperm counts, kidney disease, decreased immunity and a range of other serious health problems.

A 2011 University of Toronto study also suggests that the chemicals can leach from plastic containers at high volumes. PFAS levels in water that was left in a fluorinated container for a year measured at a startling 188,000 parts per trillion (ppt). For context, some states allow as little as 5ppt in drinking water, while public health advocates say anything above 1ppt is dangerous.

The study’s findings strongly suggest that the chemicals would leach into food and beverages, said Maricel Maffini, a researcher who studies the chemicals’ use in food packaging. “Any level of PFAS in food on top of what we already have is a problem,” she added.

The chemicals end up in or on plastic bottles through several routes. Plastic industry experts told the Guardian that PFAS are used as a lubricant during the manufacturing process to prevent containers from sticking to machinery and one another. Some amount of the chemical remains on containers that hold everything from food to cleaning products to self-care products.

Researchers with the Green Science Policy Institute in the coming months will publish a study that “detected PFAS in plastic packaging for grocery items” and its peer-reviewed paper will offer insight into how widely the chemicals are used.

Plastic companies also treat bulk containers with fluorine gas. The containers in the US are used to store fragrances, essential oils and widely used flavorings like limonene that is added to fruit juices, soft drinks, baked goods, ice cream, pudding and similar foods, or used in personal care products like shampoo and hand soap. The containers, bins and drums are also used to store fuel, paint and other industrial substances.

PFAS creates an effective barrier that prevents flavorings and fragrances from slowly permeating out of the container; prevents oxygen or moisture that could ruin the product from permeating in; and protects containers from cracking or degrading.

But plastic industry experts also say much of the contaminated plastic is recycled, which means the nation’s plastic recycling stream is contaminated with PFAS.

Such wide use creates the potential for several troubling scenarios. Plastic containers that are contaminated with the chemicals could be recycled and used to create new containers to which more PFAS are added. More residual PFAS could also rub off on the container during the manufacturing process. That hypothetical container could hold a flavoring that’s added to cola, which is then added to a new 20 ounce soda bottle that could also have PFAS on it from its production.

“In big strokes, what we are learning is creating more questions than answers, and there seems to be different levels of complexity on these questions,” Maffini said.

Several new pieces of US legislation would ban PFAS in all cosmetics and food contact surfaces, including plastic. It would also ban their use as lubricants during manufacturing of food containers. Though the EU does not prohibit the use of PFAS in food containers, it’s unclear how widely they are used in that capacity.

An EPA spokesperson said the agency was working with chemical companies and the packaging industry to understand how widely fluorinated packaging is used in at least one type of plastic, polypropylene, and how much has been leaching into pesticide. An agency spokesperson didn’t respond to questions about whether the EPA would check all types of plastic as the chemicals are used to manufacture and fluorinate more than just polypropylene.

EPA scientists recently revealed that managers at the agency have changed PFAS toxicology reports to make the chemical appear less harmful, shaking confidence in the EPA’s ability to handle the issue. And the FDA in 1983 approved the use of high levels of fluorinated gas with plastic food containers at a time when much less was known about the chemicals. The agency had “an obligation” to reassess the approval, Neltner said.

“The problem is the FDA’s failure to reassess chemicals that were previously approved,” Neltner said. “Once they approve something, they don’t reassess unless there’s [public pressure] or Congress demands it.”

An FDA spokesperson told the Guardian that it had banned several subclasses of PFAS from use in food packaging, but thousands more similar PFAS can still be used. The agency said it was also following the EPA’s study and will work with companies to remove chemicals that could be contaminating food products.

Testing plastic packaging is complicated because it is made of multiple layers and components like ink, and is often produced in multiple facilities. While regulations around each components’ use exist, nothing requires an end product to be checked.

Industry has also done less testing in recent decades, said Claire Sand, a plastic packaging consultant, and companies that do not adequately check packaging “are unwittingly complicit in the use of either unapproved or higher than allowed chemicals in direct contact with food”.

A plastic industry consultant who spoke with the Guardian on the condition of anonymity noted that multiple safe and effective PFAS alternatives exist, and are often used in Europe to store food.

“The packaging industry is glacially slow to change, so the EPA or the FDA has to say ‘No, you can’t do this’ and give them some transition period to get the PFAS out,” they said.