A glut of a sulfur-like additive released from an apologetic South Jersey gas plant swept through Philadelphia and the suburbs Friday night alarming residents and sending emergency crews on a hunt for the smell's source.
The strong acrid odor, which resembled rotten eggs, was reported from South Philadelphia through Center City and up into parts of Northeast Philadelphia and lower Bucks County.
Some people said the smell was so strong, it was making them sick to their stomach. There were no reports of anyone being hospitalized.
The first calls to emergency dispatchers and the Philadelphia Gas Works came around 9:30 p.m. as the smell moved north enveloping new neighborhoods in the thick stench.
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The city's 911 system was inundated with calls from concerned residents and the fire department and PGW dispatched crews to gas facilities in South Philadelphia.
By 11 p.m., city officials had determined the smell was caused by a chemical additive designed to give gases an odor. It was said to not be dangerous.
After initial reports that the odor came from a South Philadelphia plant, officials said too much of the sulfur-like substance was used at a Paulsboro, New Jersey plant and then wafted toward Philly.
Cherice Corley, spokeswoman for Philadelphia Energy Solutions, said she did not believe the company's oil and gas refineries were to blame.
"There is nothing so far to indicate that the smell emanated or began at their plant, but they are continuing to investigate along with all of the other refinery businesses in the area," she said.
PGW spokesman Barry O'Sullivan said the utility checked all of its facilities and did not find issues.
O'Sullivan added that at no point were natural gas levels ever elevated in the city.
PBF Energy, which runs the Paulsboro facility, apologized "to our neighbors" in a statement Saturday, saying that a brief loss of power at the refinery shortly before 8 p.m. Friday resulted in "flaring and odors." The refinery is located just across the Delaware River.
The nasty plume began to dissipate downtown around 11:30 p.m. as it continued to move north.
This wasn't the first time that a Philly stench likely originated in New Jersey, a 2014 a foul smell in South Philadelphia was blamed on a West Deptford, New Jersey plant.