After a fire and three toxic sulfur trioxide leaks from Stauffer Chemical Co., Carson Mayor Michael Mitoma said he is not satisfied with plant safety procedures and wants them reexamined.
"We need to look at the plant," Mitoma said.
Stauffer officials defended their safety program but acknowledged that they are changing the design of a pipe-heating unit to reduce the risk of the corrosion that they blame for the sulfur trioxide releases.
The 33-acre Stauffer plant, a part of the oil refinery complex in Carson for more than 60 years, purifies huge amounts of contaminated sulfuric acid used by the refineries. In a product line that is being phased out, the facility also produces lesser amounts of sulfur trioxide, which is used to manufacture detergents.
According to reports of acutely hazardous materials filed routinely with the Los Angeles County Fire Department, Stauffer typically has on hand 2 million gallons of concentrated sulfuric acid, 400,000 gallons of 30% strength sulfuric acid, 40,000 gallons of sulfur trioxide, 13,000 gallons of sulfur dioxide and 9,500 cubic feet of ammonia.
The leaking gas on a recent weekend injured no one and did not result in residential evacuations.
Nevertheless, plant manager Pete Jurichko said the incidents were the worst at Stauffer since a massive acid vapor leak in August, 1973, forced the evacuation of 150,000 people in a 25-square-mile area, sending 38 to hospitals and curtailing airport operations in Long Beach and Orange County.
In the 1973 incident, 100,000 gallons of 30% strength sulfuric acid leaked. Jurichko said the amount in the recent leak was too small to estimate accurately.
The incidents began with a fire that broke out about 5 on a Friday afternoon in the roof of a building housing a 20,000-gallon tank of sulfur trioxide.
Mitoma said he came to the plant, in the 20700 block of South Wilmington Avenue, to monitor the fire on Friday.
"I was told on Friday that there is no problem, that it is all under control. And Saturday there was a problem," he said. "There is something wrong."
On Saturday, about 6:50 a.m., a pipe connected to the tank in the building that had been on fire began leaking, producing a plume of white sulfur trioxide vapor hundreds of feet long.
Employees at the nearby Shell refinery were evacuated. Streets were closed. And safety officials watched wind direction in preparation for the possible evacuation of residential areas within three-fourths of a mile of the plant.
Stauffer employees plugged the leak shortly after 8 a.m. Another leak occurred at 9:15 a.m., and was stopped about 10 a.m. The Shell employees returned to work at about noon. Jurichko said a third leak occurred at 4 a.m. Sunday and was quickly plugged.
Jurichko labeled as "total coincidence" the fact that the leaks occurred shortly after the fire. He said that subsequent examination of the pipe showed that the three pinhole-sized holes stemmed from a leak that occurred at an undetermined time, in a steam jacket around a pipe containing sulfur trioxide.
"Nothing that the fire did caused that," he said.
Once the leak in the steam jacket started, the steam and sulfur trioxide mixture combined to produce hot and extremely corrosive sulfuric acid, which attacked the weld on a pipe flange and caused the release, he said.
"We are going to change some of that piping as a precaution," he said.
He added that initial inspections showed that the corrosion was restricted to specific piping segments but that the tank, which had last been inspected in 1983, will now be inspected thoroughly.