No Alarms Sounded for Toxic Spill That Injured 3, State Says : Chemicals: Cal-OSHA concludes that a sensor system was inactive when hydrogen fluoride escaped at a Torrance refinery.

Alarms did not sound at Mobil Oil Co.’s Torrance refinery in June when a small amount of a highly toxic chemical was released and injured three contract workers, according to a Cal-OSHA review of the incident.

The state worker safety office said an automatic sensor system designed to detect such spills was inactive when a cloud containing hydrogen fluoride escaped accidentally.

And a Mobil supervisor who saw the 10-foot-diameter cloud did not trip an alarm manually because he thought the vapors were headed for an area where no workers were present, the Cal-OSHA report said.

Based on the review, Serv-Tech Inc. of Torrance, which employed the three men, was issued a citation by the state Occupational Safety and Health Administration for failing to ensure that its personnel were warned of the danger. The workers were hospitalized after the accident for eye and respiratory problems, and released within three days.

A company official said Serv-Tech has appealed the citation, which carries no penalty.

Mobil was not cited in the accident because it is not the employer of the contract workers.

Mobil asserted last week that the state’s findings contain “factual errors.” The oil company said it is possible that chemicals less harmful than hydrogen fluoride escaped and that sensors capable of detecting a significant release of the extremely toxic gas were functioning.

“There were two (hydrogen fluoride) detectors operating at the time of the incident,” Mobil said in a statement released by company spokesman Barry Engelberg. “If high concentrations of (hydrogen fluoride) were present and in the path of the detectors, they would have sounded.”

Hydrogen fluoride is the gaseous form of hydrofluoric acid, a highly toxic chemical that some refineries use as a catalyst in the manufacture of unleaded gasoline. Capable of forming a lethal, ground-hugging cloud if spilled, the chemical has become the target of increasing scrutiny in recent years on the local, state and federal level.

The South Coast Air Quality Management District, after studying the issue for more than a year, is slated to vote in March on a proposal to phase out bulk use of hydrofluoric acid by 1995. Mobil, pressed by Torrance, has agreed to stop using the acid locally by Dec. 31, 1997, if it cannot develop a safer form of the substance before then.

The accident that prompted the Cal-OSHA review was a chemical release June 11 in the alkylation unit, where hydrofluoric acid is used.

According to the agency, the alkylation unit supervisor said a brief leak occurred as workers prepared the unit for an overhaul. It was caused when a coupling accidentally came loose on a line being used to flush out the unit. The leak created a gray, 10-foot-diameter cloud.

In its statement last week, Mobil said the cloud may have been a combination of isobutane, ammonia and ammonium fluoride, since significant quantities of these substances were present. But that view appeared to be contradicted by the alkylation unit supervisor, who was quoted by Cal-OSHA as saying he “smelled HF acid” and did not smell ammonia.

The Mobil supervisor said he decided not to trip the alarm because wind pushed the low-floating cloud away from the unit--into an area where, he thought, no workers were present. However, the cloud drifted into a nearby unit being serviced by the three Serv-Tech workers.

The men told state investigators that they had no warning and began suffering respiratory difficulties and eye irritation as soon as the cloud reached them. All three were taken to Torrance Memorial Medical Center.

It was unclear how long the men were exposed to the gas, though they apparently fled the cloud as fast as they could.

A Cal-OSHA medical authority reported that the workers complained of shortness of breath, coughing and burning in the chest in follow-up examinations at Torrance Memorial. However, medical tests after two weeks detected no evidence of “continued impairment,” he wrote.