The East Rink at Bethlehem's Steel Ice Center temporarily was evacuated Wednesday night because of high levels of carbon monoxide.
Doors were opened and fans placed at each end of the rink to quickly bring down the CO levels to the acceptable range, said Clyde Smoll, general manager of Steel Ice Center.
Smoll did not reveal how many people were evacuated or whether any were ill. Bethlehem fire officials could not be reached for comment.
It was the second time in one month that the rink was evacuated because of high carbon monoxide levels.
On Jan. 11, a faulty Zamboni machine sent 20 people to the hospital and forced the evacuation of about 300 people, after it leaked dangerous carbon monoxide levels into the Steel Ice Center.
After that incident, said Moll, both Zambonis were serviced, inspected and approved for use.
But until the exact cause of the latest higher-than-normal levels is determined, the East Rink Zam has been quarantined, he said.
"We will reinstate the precaution of opening doors and running fans until a long-term solution is found," said the manager. "Please do not be alarmed to see the doors open and fans on. It will be done during every Zamboni resurfacing as a precaution.
"Unfortunately the solution is not a simple one and there is no quick fix, but even before the last incident, we have been seeking answers and solutions. It is part of our daily routine to research options and solutions.
"Please be assured that we are concerned about the safety of our customers, employees and the environment in which we work every day and our customers skate."