Philadelphia officials closely monitor drinking water after a chemical spill in the Delaware River

 (CNN) -- Philadelphia officials are monitoring the city's drinking water system carefully following a chemical spill upstream in the Delaware River, saying the water would be safe to drink until at least 11:59 p.m. on Monday.

"The water that is currently available to customers was treated before the spill reached Philadelphia and remains safe to drink and use for bathing, cooking and washing," the city said Sunday in a statement.

None of the three chemicals that leaked into the river when a latex product spilled Friday have so far been detected in Philadelphia's water system, city officials said. Still, residents swarmed grocery stores as news of the spill spread to stock up on bottled water.

"It's not the sort of thing you want to mess around with," said Kim Kelly, a "gallon-a-day kind of gal" who on Sunday found some shelves bare at one South Philadelphia store. "I feel like someone should reimburse all of us for all the money we're spending on all this water because it's not our fault."

The spill -- which "appears to be the result of equipment failure," the facility's owner said Sunday -- raised immediate concerns about possible health threats. At least one of the discharged chemicals, butyl acrylate, is among contaminants of concern identified in last month's train derailment in East Palestine, Ohio.

Ethyl acrylate and methyl methacrylate also spilled into the Delaware River, officials said.

"Butyl acrylate, in particular, is a chemical that was identified in the spill in East Palestine. So, we understand there are some known health effects and their established thresholds in terms of the parts per billion that the EPA feels are safe," Michael Carroll, Philadelphia's deputy managing director for transportation, infrastructure and sustainability told reporters Sunday.

The city initially sent out mobile phone alerts recommending residents use bottled water starting at 2 p.m. on Sunday due to the spill. Then late Sunday afternoon, they said they were confident tap water from the Baxter Drinking Water Treatment Plant would remain safe to drink until at least the end of Monday.

The water would continue to be monitored, Carroll said. "Again, I want to reiterate, we have not detected any of these contaminants in our water and will continue to use that as our first basis for any decision-making that we make."

"We have enough water to sustain a safe use for drinking, cooking -- all purposes -- through till at least 11:59 p.m., Monday, March 27," he said. "The potential for contamination is diminishing over time."

The city's advice on the tap water's safety was updated "based on the time it will take river water that entered the Baxter intakes early Sunday morning to move through treatment and water mains before reaching customers," it said in a statement.

The Philadelphia Water Department provides water to more than "2 million people in Philadelphia, Montgomery, Delaware, and Bucks counties," its website says. It is posting online updates regarding the spill.

How the spilled chemicals can harm health

No evidence of contamination plumes was seen during a flyover by the Philadelphia Police Department and Pennsylvania Department of Environmental Protection, Carroll told reporters Sunday.

"In this case, because we were talking about essentially ingredients that go into latex paint, we would have been able to see a kind of white plume under the river surface," he said.

Some 60,000 gallons of contaminated water had been collected from the chemical spill, the Coast Guard said in a statement Sunday night. "Clean-up is primarily focused on removing product from the storm drain system and outflow located on Mill Creek," it said.

Coast Guard pollution responders conducted shoreline patrols Sunday morning and observed no visible product along the Delaware River, the statement reads. The Coast Guard had not gotten any calls reporting injured or affected wildlife, it said.

Among the chemicals that spilled:

• Butyl acrylate is a potentially flammable colorless liquid with an acrid odor which can cause irritation of the eyes, skin and respiratory system, according to the US Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health.

• Ethyl acrylate can cause irritation symptoms depending on exposure, the CDC says. Both are often used in the manufacturing of paints and adhesives.

• Methyl methacrylate, sometimes called MMA, is a colorless liquid with a fruity odor often used in the production of acrylic plastics and resins. Exposure to MMA can cause irritation to the eyes, skin, nose and throat as well as skin inflammation. The polymer version of MMA is often used in dental applications.

The contamination occurred Friday night and involved a latex product that spilled along a Delaware River tributary in Bristol Township, Bucks County, Carroll earlier said in a statement.

"The Philadelphia Water Department (PWD) became aware of this through the Delaware Valley Early Warning System (EWS) and has been evaluating the situation since that time to understand potential impacts to the public," the statement reads.

Equipment failure appears to be factor, company says

Trinseo PLC, which owns the facility where the spill occurred, said it "appears to be the result of equipment failure" at the Bristol, Pennsylvania, plant, which manufactures acrylic resins.

An estimated 8,100 gallons of solution -- half water and half latex polymer -- was spilled, the company said Sunday in a statement on its website.

"The latex emulsion is a white liquid that is used in various consumer goods. Its pigmentation makes the water-soluble material visible in surface water," Trinseo said.

The Pennsylvania Department of Environmental Protection said an "unknown amount" of the spilled product had entered the Delaware River. Fish and wildlife are said to have not been affected, according to the statement.

"Since the first hours after the incident, the Department of Environmental Protection has been at the facility where the spill originated and will be staying until there is no longer a threat to those impacted in Bucks and Philadelphia counties," the department's acting secretary Rich Negrin said in the statement.

"We are working closely with our partners to monitor the spread of the contaminants and we will hold the responsible party accountable."