Fire Next to Acid Tank Routs 1,200 : Accident: The blaze at Rocketdyne sent 10 workers to hospitals but officials said hysteria was to blame for some injuries reported by others.

About 1,200 workers were evacuated Thursday morning when a fire broke out next to a 900-gallon acid storage tank at the Rockwell International plant in Canoga Park where space shuttle engines are built, authorities said.

Paramedics and doctors examined 57 workers who complained of feeling ill and sent 10, including three Rocketdyne firefighters, to area hospitals for observation and treatment.

Some of the injuries, fire officials later said, appeared to result from hysteria felt by people imagining they suffered symptoms from exposure to toxic chemicals.

The fire, in a 50-by-250-foot parts washing area at Rockwell’s Rocketdyne Division in the 6600 block of Canoga Avenue, was spotted about 9:20 a.m. next to the acid storage tank. The fiberglass tank contained a highly toxic mixture of nitric and hydrofluoric acids and water that is used to clean stainless steel components for shuttle engines, company officials reported.

“There were people working in the area at the time, but they got out right away,” Rocketdyne spokesman Pat Coulter said.

Dan Boyd, manager of the area where the fire began, said he saw flames leaping as high as seven feet from the side of the tank and other workers said smoke from the fire spread through the ventilation system of the vast building, known as Building 001.

Three firefighters from Rocketdyne’s on-site fire department responded to an alarm and battled the blaze until Los Angeles Fire Department firefighters arrived minutes later.

The fire was extinguished quickly, but officials were uncertain whether it had caused the tank to rupture and initially reported that as much as 900 gallons of the acid mixture had leaked.

That report was contradicted after firefighters in yellow protective “moon suits” examined the area and determined that the tank had not ruptured but had merely been scorched. The only material that burned, officials said, was paint on the outside of the tank.

Had the acids escaped, “it could have been quite serious, because that is very potent material,” said Inspector Ed Reed, a spokesman for the Los Angeles Fire Department. “It could be lethal.”

Nitric acid vapor is highly corrosive to the skin, eyes, lungs and gastrointestinal tract and can cause fluid to build up in the lungs and, if the chemical is concentrated enough, death, said Frances Weindler, assistant administrator of the Los Angeles Regional Poison Control Center. Hydrofluoric acid is also highly corrosive to skin and mucous membranes.

The fire is under investigation and a cause has not been determined. Assistant Fire Chief Alan Schroeder speculated that the blaze may have resulted from a chemical reaction.

But Al Ybarra, president of United Auto Workers Local 887, which represents about 2,200 workers at Rocketdyne, said a union safety representative at the plant told him the fire was caused by acid that spilled on a wooden floor near the tank.

The Fire Department dispatched 20 engine companies, three rescue crews and 85 firefighters and called two additional private paramedic crews to the scene.

Workers examined by medical personnel complained of scratchy throats, dizziness, nausea and breathing difficulties. Four of the workers were sent to Kaiser Hospital Medical Center in Woodland Hills; four were taken to Canoga Park Hospital, and two went to the Nu-Med Regional Medical Center.

All but one man, who was said by a spokesman at Canoga Park Hospital to be suffering from smoke inhalation, were later sent home. Schroeder said earlier that most of the injuries probably resulted from “hysteria.”

Evacuated workers stood on nearby sidewalks for about three hours before being told they could go home. They strolled to nearby markets, sat on street curbs and speculated about the seriousness of the fire.

Most said that the evacuation had been quick and orderly and that employees followed procedures practiced in earthquake drills.

“I think it was handled pretty smoothly, mainly due to the previous training that employees have had,” said a man who complained of a sore throat after the evacuation.

But Pat Thomas, who also works in Building 001, said many employees “can’t hear the public address system” that was used to announce the evacuation and “weren’t aware of what was taking place.”

Dwight Ford, a machinist in the building, said he was not overly concerned about the dangers of his job.

“It doesn’t bother me,” he said. “I figure our environment is hazardous to our health. If I were worried about hazardous chemicals, I wouldn’t be making the money I’m making.”

Worker safety inspectors from Cal/OSHA inspected the area Thursday.

Between 1978 and 1986, Cal/OSHA inspected the facility a dozen times. Violations were found on three of those occasions, but details about the nature of the violations were not immediately available, a Cal/OSHA spokesman said.

The fire comes at a time when Rockwell’s Santa Susana Field Laboratory, west of Chatsworth, is embroiled in controversy over its request to renew a license to handle nuclear materials. The license renewal is opposed by neighborhood activists and environmental groups that say the nuclear work is inappropriate in a populated area.

Many merchants and customers of Topanga Plaza shopping center, across the street from the Canoga Park plant, said they were unaware of the fire.

“Everywhere you go there are hazardous materials in one form or another,” said Tim Bekins, manager of a nearby market. “You can work next to a gas station and it can go up in flames. It’s a sad situation, but you can’t run from it.”

Marcia Sarka, a shopper who lives nearby, said she worries about the possibility of a major accident.

“I didn’t really think about it before,” Sarka said. “I just hope the people we elected are doing their job, making sure that all the necessary safety measures are in place.”

Times staff writers Myron Levin and Bob Baker contributed to this story.