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What we know about the chemicals raising concern about Philly’s drinking water

Officials named three chemicals that were involved in the spill: butyl acrylate, ethyl acrylate, and methyl methacrylate.

The Trinseo Altuglas facility in Bristol, Pa. on Monday after an estimated 8,100 gallons of a latex emulsion solution spilled into Otter Creek and then into the Delaware River late Friday.
The Trinseo Altuglas facility in Bristol, Pa. on Monday after an estimated 8,100 gallons of a latex emulsion solution spilled into Otter Creek and then into the Delaware River late Friday.Read moreMonica Herndon / Staff Photographer

Many Philadelphia residents may have concerns about a chemical spill that has triggered the city to issue drinking water alerts. For starters, what are the chemicals involved in the spill, and how dangerous are they?

The Inquirer talked with experts and examined the scientific research to help answer questions from readers about the chemicals in the estimated 8,100 gallons of latex solution that spilled into a Delaware River tributary in Bucks County on Friday night.

Here is what you need to know about the chemicals and their potential impact on health.

Is the drinking water in Philadelphia safe?

Yes, at least until 3:30 p.m. Tuesday, according to the city.

On Friday, chemicals spilled from the Trinseo plant in Bristol into Otter Creek, which feeds into the Delaware River. That night, the city shut down the nearby Baxter Water Treatment Plant — the source of water to all of Philadelphia’s faucets east of the Schuylkill — then re-opened it on Sunday to maintain minimum water levels.

» READ MORE: Live coverage: Philadelphia water quality updates following Bucks County chemical spill

Philadelphia’s drinking water remains safe until at least 3:30 p.m. Tuesday, officials said Monday. Testing near the Baxter Water Treatment Plant by authorities did not show contamination of the materials that were spilled into the water.

What are the chemicals that spilled in the Delaware River?

The solution that was leaked is 50% water and 50% latex polymer, according to Trinseo. Officials identified three specific chemicals involved in the spill:

  1. Butyl acrylate is a clear, colorless liquid that has a fruity odor. It is used in the manufacturing of paints and solvents. The material was in the news recently because it was also released into the environment after a train derailment in East Palestine, Ohio.

  2. Ethyl acrylate is found naturally in pineapple, and evidence that it could cause cancer is weak, according to the National Center for Biotechnology Information. It is used to manufacture latex paints and adhesives.

  3. Methyl methacrylate is used to make plastics and has a fruity and “acrid” odor. It is also used in dentistry to create ceramic fillers and prosthetic devices.

How dangerous are these chemicals in water?

When inhaled in large concentrations, these chemicals can cause irritation in the nose, throat, and lungs — especially butyl acrylate. But less is known about their effects when ingested through water, said Keeve Nachman, associate professor of environmental health and engineering at Johns Hopkins University.

At low levels, they are unlikely to cause lasting harm, he said.

» READ MORE: A Delaware River latex spill contaminated Philadelphia’s drinking water: What we know and don’t know

“People need to drink water [that is contaminated at] fairly high levels for a long time before we anticipate any potential negative health effects,” he said.

Butyl acrylate can irritate the skin, said Ted Schettler, a physician and the science director at the Science and Environmental Health Network, an environmental nonprofit advocacy organization. If it is present in the water, even at lower levels, he advised that it could be safer to avoid bathing.

Will the water be dangerous for people with a latex allergy?


A latex allergy is a reaction to proteins present in the natural rubber latex, which is made off rubber trees. Other chemicals that can also be in latex, such as those spilled in Bucks County, will not cause a reaction.

Jonathan Spergel, chief of the allergy program at Children’s Hospital of Philadelphia, stressed by email: “Not an issue. You are allergic to protein, not the chemical in the water.”

Are the chemicals considered PFAS?


PFAS, or per- and polyfluoroalkyl substances, are known as “forever chemicals” because they don’t break down in the environment. They have been linked to a host of illnesses including brain tumors, kidney and testicular cancer, decreased fertility, weakened immune system, and thyroid disease.

There are an estimated 12,000 PFAS. The substances identified in the spill are not among them.

» READ MORE: What to know about ‘forever chemicals,’ artificial turf, Phillies cancer deaths, and our story