City officials said Friday afternoon that air testing taken during the day at the site of the refinery fire in South Philadelphia showed no immediate cause for alarm for workers at the site or residents nearby.

“Preliminary testing both at the site of the refinery and in the adjacent community has shown no ambient carbon monoxide, hydrocarbobutanens (combustibles), or hydrogen sulfide,” James Garrow, spokesperson for the health department, said in a statement.

Garrow said the city took air quality samples upwind and downwind of the refinery. The samples were taken to the city’s Air Management Services Laboratory and were tested for 61 different chemical compounds, none of which were found to be at “or even near” harmful levels.

He said the danger from smoke from the fire, which could exacerbate asthma, had passed and the health department had not gotten reports of an increase in asthma-related complaints.

The testing was prompted by the explosion of a propane tank at the Philadelphia Energy Solutions (PES) refining complex on Passyunk Avenue. The early morning blasts and resulting fire woke neighbors, and residents as far away as Deptford, Gloucester County, reported their houses shook.

An Environmental Protection Agency database shows the refinery has had at least two violations in two years that led to fines — one under the Clean Water Act and one under the Resource Conservation and Recovery Act, which governs solid and hazardous waste disposal. PES was assessed $250,000 in penalties for the violations. Over the last five years, the company was fined $649,417 in penalties for violations.

The database also shows the company has had high-priority violations in nine of the past 12 quarters involving the Clean Air Act. The context of those violations or whether they posed any threats to the public was not immediately clear. The violations were reported by the department of health’s Air Management Services.

Friday morning, Cosmo Servidio, mid-Atlantic regional administrator for the EPA, said the federal agency dispatched a team of emergency responders, including scientists, to the site to set up air monitors.

David Sternberg, an EPA spokesperson, said the agency had an on-scene coordinator at the site working with other officials. He said the EPA’s immediate air monitoring did not show any “contaminants of concern” above regular levels at the fence line.

The PES complex, at 1,400 acres, is the largest refining complex on the eastern seaboard, according to the company. It processes about 335,000 barrels of crude oil per day. Its two refineries, Girard Point and Point Breeze, are next to each other with easy access to highways, pipelines, rails and docks.

The complex produces gasoline, low-sulfur diesel fuel, jet fuel, kerosene, butane, propane, home heating oil, and the petrochemical cumene, PES says.

PES is required to file a risk management plan every five years. The publicly available portion of the most recent plan, filed in 2017, showed one accident in recent years involving the release of 8,000 pounds of propane after an equipment failure on Dec. 10, 2016. No one was injured.

The plan also lists some chemicals, including propane, that the EPA has identified as having the potential to cause significant off-site consequences in the event of a major accidental release. The others include hydrogen fluoride, modified hydrogen fluoride, butane, isobutane, ethyl mercaptan, and a flammable mixture that can contain more than a dozen chemicals.

On Friday, PES said there were three separate explosions that “impacted” a unit that produces alkylate, which is used to boost gasoline octane. One unit that appears to have been involved uses deadly hydrofluoric acid (HF) as a catalyst. HF acid releases have been implicated in several dangerous refinery incidents.

The Clean Air Council, a nonprofit environmental organization, sent a letter Friday to the U.S. Chemical Safety and Hazard Investigation Board “to immediately begin an independent investigation of the conditions” that led to the fire. The group singled out HF as “an extremely dangerous substance” and noted that the Steelworkers union has called for its phase-out. The board agreed to send four investigators, the council said.

Alex Bomstein, a senior attorney for the Clean Air Council, said the nonprofit has been concerned “for many, many years” about the refinery. He said that although initial air testing might not show immediate concerns, later tests could produce different results depending on how and where monitoring is carried out. He said he was skeptical that there was no health concern for residents.

“When you see a plume of black smoke, you’re seeing pollution,” said Bomstein, who lives in South Philadelphia and saw the plume rise over the neighborhood.

“How much of that reaches the monitors, I don’t know,” he said. “So we are still very concerned.”

Peter DeCarlo, an associate professor of environmental engineering at Drexel University, agreed.

DeCarlo, who specializes in outdoor air quality and pollution, explained the black color of the smoke likely indicated there was carbon being emitted, the product of an incomplete combustion process.

He said fuels that don’t burn completely can produce pollutants that can lead to health concerns.

Staff writers Wendy Ruderman and Maddie Hanna contributed to this article.