Can a Brita filter or boiling water help following the Delaware River chemical spill?

You can’t see or filter out the chemicals that could contaminate the drinking water of more than half of Philadelphia’s residents following a chemical spill in Bucks County.

City officials set off a rush on bottled water Sunday when they initially urged residents to switch to bottled water, then later said the city’s drinking water was safe.

As of Monday, city officials say tap water is safe to drink until at least Tuesday afternoon. The chemicals that spilled can be harmful with prolonged exposure to significant concentrations, but have not been found in city drinking water.

» READ MORE: Live updates: Latest on Philadelphia water following Delaware River spill

Here’s what to know if you are confused and worried about water safety as state and federal officials are investigating the spill of about 8,000 gallons of latex finishing product at the Trinseo chemical plant in Bristol Borough.

No. At-home water filtration systems, such as a Brita filter or other carbon filters, are tested by the National Sanitation Foundation and rated for their ability to remove different contaminants.

But those tests do not include the three chemicals spilled into Otter Creek, which feeds into the Delaware River — butyl acrylate, ethyl acrylate, and methyl methacrylate — so there’s no guarantee that a home water filter would be able to remove them, said Robert Laumbach, an associate professor of environmental and occupational health at Rutgers School of Public Health.

More advanced home water filters may be tested for more contaminants and you can contact the manufacturer for a full list.

Regardless, toxicity depends on both the contaminant and how much of it is present.

“The level of exposure, the dose, is what makes the poison,” Laumbach said.

Even if a home filter were able to remove some of the spilled chemicals, it may not be able to remove enough contamination to ensure safe drinking water, he said.

» READ MORE: What we know about the chemicals raising concern about Philly’s drinking water

Not in this case. Boiling water can kill bacteria or viruses that may be present, which is why this is often recommended after sewage spills.

But boiling will not destroy or inactivate chemicals present in water, Laumbach said.

There is no fail-safe home test for these chemicals. All three have odors that have been described as “fruity” or “acrid” by the Centers for Disease Control and Prevention.

If the water has an odor, “it’s reasonable to ask questions,” said Keeve Nachman, an associate professor of environmental health and engineering at Johns Hopkins University. But he advised against using a smell test alone to gauge water safety. “The absence of an odor by itself is not enough to really make judgments about the safety of the water,” he said.

» READ MORE: Where Philly’s drinking water comes from

The city will continue to test water entering the Baxter Water Treatment Plant in Northeast Philadelphia over the next couple of days and will alert the public if unsafe chemical levels are detected.

This map shows which parts of Philadelphia are likely affected.