PHILADELPHIA — The city of Philadelphia sent its 1.5 million residents into a mad dash for bottled water after issuing — and retracting — a tap water advisory on Sunday afternoon.

The cause: a chemical spill from a Bucks County latex finishing plant into a Delaware River tributary that feeds into a Philadelphia water processing facility. Current guidance from city officials says residents should be able to guzzle and cook with tap water through Monday night, but that could change as more tests are conducted.

Here’s what we know:

—Is it safe to drink Philadelphia’s tap water?

Yes — for now.

The city’s latest guidance says Philadelphia tap water will be safe to drink at least through Monday at 11:59 p.m. That update came after officials had issued a bottle advisory starting 2 p.m. Sunday “out of an abundance of caution.”

Philadelphia officials said they found no contaminants in water taken in at the city’s Baxter Water Treatment plant, which serves the part of the city east of the Schuylkill.

“There’s no need at this time for people to be rushing out and buying bottled water,” said Mike Carroll, the deputy managing director for Philadelphia’s Office of Transportation, Infrastructure and Sustainability (even though that already happened). “Based on all the testing we’re seeing, the situation is one where the potential for contamination is diminishing over time.”

That could change, however, as city officials test water that flowed into the Baxter plant from the Delaware overnight.

—How did the chemical spill happen?

The spill occurred at a Trinseo plant in Bristol, Bucks County, on Friday, when the company said “an equipment failure” dumped about 8,100 gallons of latex emulsion solution into Otter Creek, a tributary of the Delaware River.

Latex emulsion solution is about 50% water and 50% percent latex polymer, per Trinseo, but it also contains butyl acrylate, one of the chemicals released in the East Palestine, Ohio, train derailment.

Trinseo’s statement said the chemical mixture “overflowed the on-site containment system and entered a storm drain, where it flowed to Otter Creek and then to the Delaware River.”

The company is conducting a review of vulnerabilities in their latex processing system, but it’s unclear if the plant is currently operating.

—What has monitoring shown?

Philadelphia closed the Baxter Water Treatment facility on Friday following the spill, but reopened it Sunday to maintain minimum water levels.

Carroll said the Pennsylvania Department of Environmental Protection and Philadelphia police did a flyover of the Delaware River and “saw no visual evidence of any plumes” from the spill.

For their part, the DEP said that latex emulsion solution was not leaking from the facility as of Sunday morning and that contaminants have yet to be detected in drinking water intakes. There have not been signs of harms to fish or wildlife, either.

—Who is impacted?

All Philadelphia neighborhoods east of the Schuylkill could be impacted, per a map released by the city Sunday afternoon. The areas of the city not impacted by the chemical spill include Southwest and West Philly, plus parts of Northwest Philly, like Roxborough and Chestnut Hill.

Across the Delaware, New Jersey American Water asked Camden, Burlington and Gloucester counties to indefinitely limit water usage as a result of the spill, even though it likely did not impact treated drinking water at the area’s Delaware River Regional Water Treatment Plant.

Over in Bucks county, officials said the region’s water providers — Pennsylvania American Water, Aqua, and the Lower Bucks Joint Municipal Authority — all advised that “there are currently no known adverse impacts to drinking water.”

—What chemicals are in the water?

The spill released three main chemicals: ethyl acrylate, methyl methacrylate and butyl acrylate.

Carroll, the OIT spokesperson, said the risks associated with them are “very low,” and that people who ingest water should “not suffer any near-term symptoms or any acute medical conditions”

Boiling the tap water won’t remove the chemicals, but you can still bathe or wash dishes with the potentially contaminated water.

—What are their side effects?

Ethyl acrylate: This possible carcinogen creates paints and plastics. Acute exposure can cause headaches, drowsiness, and nausea.

Methyl methacrylate: This resin is commonly used as cement in dentistry and orthopedic surgery. It’s not considered a carcinogen.

Butyl acrylate: If inhaled in large quantities, this flammable chemical can cause respiratory issues. It can also cause irritation if it comes in contact with eyes or skin.

Long-term side effects of ingesting these chemicals — especially via water, are unknown, according to Keeve Nachman, associate professor of environmental health and engineering at Johns Hopkins University.

Still, “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.

—What is Trinseo?

Trinseo is a plastic manufacturer formerly owned by Dow Chemical and the European Plexiglass purveyor Altuglas International.

Trinseo specializes in “latex binders,” which are a versatile mixture of chemicals: Latex binders make cement malleable, create waterproof coatings, and help make things like textiles and medical machinery sturdy.

—Is there water left to buy?

It varies.

The initial bottled water advisory caused a run on water that spanned grocery and convenience stores across the city and some suburbs.

Some stores were limiting water items to four per customer as people hoarded cases of water, a la the toilet paper shortage of 2020.

At least one Philadelphia grocery chain is prepared for another deluge of panic: All Philadelphia Acme stores are stocked with water bottles as of Monday morning, though quantity and brand will vary across locations.