As tap water contaminated with so-called “forever chemicals” has affected thousands of residents in Pennsylvania and other states, many have turned to bottled water as a safer substitute. But the discovery of PFAS in jugs of spring water being sold in New England has sparked concern about contamination in bottled water, too.

The tainted bottled water in Massachusetts, Connecticut, and New Hampshire raised familiar questions for residents, officials, and local governments that have been dealing with the harmful chemicals in tap water: How much PFAS is safe to drink, and when will it be regulated?

The Food and Drug Administration does not require bottled water testing or have set standards for PFAS, which have been linked to potentially serious health problems, including cancers, thyroid issues, and lowered fertility. There is no federal standard for PFAS in public drinking water, either, but scientists have said restrictive standards are needed for any drinking water and some states have begun creating their own.

On Monday, Sen. Richard Blumenthal (D., Conn.) called on the FDA to set limits for PFAS in food and bottled water, saying in a letter to the FDA that the agency “shirks its duty” to the public health “without swift and ambitious action to reduce PFAS in drinking water.”

“Given the widespread persistence of PFAS in our environment and drinking water, many people have turned to bottled water to avoid adding toxins to their bodies. In light of this, it is especially concerning that bottled water may contain PFAS in unsafe concentrations,” Blumenthal said in a statement Monday.

Spring Hill Farm Dairy Inc., based in Haverhill, Mass., sold the PFAS-tainted one-gallon jugs discovered on store shelves in New England. The company distributes water primarily in New England but also in a few other states, including New Jersey, said company spokesperson Nancy Sterling. It does not distribute water in Pennsylvania.

Spring Hill’s water is sold under a variety of brands at Whole Foods, CVS, and other grocery and convenience stores. Labels on affected jugs show the water source as Spring Hill Spring, Massachusetts officials said. Sterling said the company installed a filtration system last week to remove PFAS from its water, but tainted jugs could still be on store shelves.

“Spring Hill’s new $100,000 filtration system was quickly installed on July 22 and all PFAS should be eliminated from bottles after that date,” Sterling said.

Some bottlers are already testing for PFAS voluntarily. The International Bottled Water Association, which began requiring its members to test for PFAS in January, said Tuesday that 97 percent of them do not have detectable traces of the chemicals in their water. The group’s members include major companies like Nestle (which bottles Deer Park, among other brands), Danone, Fiji, CG Roxane, and DS Services.

Though Pennsylvania regulates bottled water providers, the state does not require PFAS testing and does not have plans to do so, Department of Environmental Protection spokesperson Elizabeth Rementer said Tuesday.

“We are monitoring other states’ actions to gain a better sense of the prevalence of PFAS contamination in water and other sources,” Rementer said.

The contamination was discovered in New Hampshire during tests state regulators conducted while preparing to implement new drinking water regulations. The amount of PFAS found in the water exceeded the state’s new regulations for public water providers, meaning the state considers it unsafe to drink.

In Massachusetts officials advised pregnant women, nursing mothers, and infants to avoid the tainted jugs. The advisory noted that Spring Hill still has a valid permit and is in good standing to produce its spring water.

Residents in Bucks and Montgomery Counties, where some of the first widespread PFAS public water contamination was found, are among those who have turned to bottled water — sometimes voluntarily, but sometimes out of necessity.

Over the last five years, federally mandated testing of public water systems has revealed PFAS contamination in states from Pennsylvania to California. PFAS, or per- and polyfluoroalkyl substances, are man-made chemicals used in products from food wrappers to nonstick cookware.

The Environmental Protection Agency announced in February that it would move toward regulating PFAS in drinking water, groundwater, air, and soil, but other officials and advocates have criticized the federal government for not moving quickly enough.

Meanwhile, the FDA recently tested for the chemicals in some food, finding elevated levels in crops grown near areas with known PFAS contamination. After those test results were made public in June, the FDA said it would begin sampling food to assess human exposure to PFAS through food.

The International Bottled Water Association set a limit of 5 parts per trillion (ppt) for any one type of PFAS and 10 ppt for any combination of PFAS chemicals in a bottle’s water, but said only 3% of water sampled in the organization’s monitoring program was above 2 ppt. All the water sampled was below the EPA’s health advisory, said spokesperson Jill Culora on Tuesday. Many member companies began testing for PFAS several years ago, she said.