ConocoPhillips said there was a short release of light hydrocarbons due to an upset at an unspecified unit at its Alliance Refinery in Belle Chasse.

The release occurred around 9 a.m. on Wednesday February 1, and lasted for approximately four minutes.

“We had an overhead atmospheric release valve open for about two to four minutes,” said ConocoPhillips rep Dennis Nuss. “There were hydrocarbons present in the release.”

There was no immediate threat to safety, and the release was environmental only, Nuss said, but had breached the maximum level without reporting for environmental purposes.

“There was no potential safety issues or impact to the surrounding community, but the state requires a report past a certain point, but there was no kind of danger,” Nuss said.

Hydrocarbons, which are a component of oil and certain fuels, can be toxic enough to cause damage to the central nervous system or even kill.

The Alliance refinery was established in 1971, and can process up to 247,000 barrels of crude oil a day.