A portion of Hanua Street in Campbell Industrial Park was closed off this morning by police while firefighters, including a hazardous materials team, worked with employees of Air Liquide to seal a leaking valve on a tank of liquid nitrogen.

Fire Capt. Terry Seelig, said a passing motorist noticed the leak and reported it about 6:44 a.m.

Seelig said the super cold liquid nitrogen was leaking from a fill-valve on the 6,000 gallon tank which was mounted on a trailer inside the yard at the company's plant at the industrial park. Approximately 1,000 gallons of the liquefied gas were in the tank when the leak was discovered, Seelig said.

When the extremely cold nitrogen came in contact with the much warmer air, it created "an eerie white cloud" that clung to the surrounding ground, Seelig said.

"It was not a super hazardous situation," Seelig said. "The primary danger was that, in its liquid state, the nitrogen is so cold it could cause damage to the body if it came in contact with it or could cause oxygen to be displaced," Seelig said.

Firefighters and company workers applied water to the frozen valve until they could use wrenches to seal off the leak, Seelig said.

The situation was declared under control at 7:20 a.m.