The leak that has been causing higher than usual hydrogen cyanide emissions at the Delaware City refinery since Oct. 2 has been fixed, PBF Energy spokesperson Mike Gayda said Tuesday.
The refinery began filing reports with the National Response Center earlier this month when one of their boilers cracked and had to be shut down for repair.
This caused up to 200 pounds of the chemical to be released each day.
“It is unusual for us to emit anything but trace levels,” Gayda said.
Since the refinery does not have permits to emit this much hydrogen cyanide, they have to file the reports, Gayda said.
“Based on an analysis of the emissions, DNREC does not consider there to be a threat to public health,” said Michael Globetti, a spokesperson for the Department of Natural Resources and Environmental Control. “Even at its source within the refinery, the HCN now being released is exponentially less than the permissible threshold for exposure allowed under federal law."
In the most recent report filed Oct. 23, the unidentified caller told the NRC that a CO Boiler on the FCC unit blew a hole in the line causing a release of hydrogen cyanide and that the unit has been shut down for repair.
A low level concentration that is about 10 parts per million was emitted into the air, Gayda said.
He compared this to a drop of soy sauce in a pot of water.
“The highest concentration of HCN was projected to occur approximately three-fourths of a mile from the source at a concentration of 3 parts per billion,” Globetti said. “By comparison, the Occupational Safety and Health Administration’s permissible exposure level to HCN without adverse effects is 10 parts per million.”
On Oct. 2, the first report submitted to the NRC said that the “CO Boiler on the FCC united blew a hole in the line causing a release of carbon sulfide and hydrogen cyanide into the air,” emitting only a trace amount of the chemicals.
Gayda said that there was no “high level” and that a person can work all day in the area with out being affected.
He said that other facilities emit much greater levels of hydrogen cyanide on a routine basis.
The Comprehensive Environmental Response, Compensation and Liability Act requires that refineries have to notify the NRC if they release hazardous substances in excess of reportable amounts.
DNREC expects a carbon monoxide boiler whose outage at the refinery led to the HCN release to be back in operation within days, following repairs, Globetti said. The boiler outage will be investigated in accordance with DNREC's standard practices.
The Delaware City refinery reopened Oct. 7 after being closed for nearly two years.
The refinery is a high conversion heavy crude oil refinery, with capabilities of processing 190,000 barrels per day. It is located on 5,000 acres of land near the Delaware River.
