An accident Friday morning at Geneva Steel forced plant managers to shut down a pollution control system for 21/2 hours, sending an immense cloud of bright orange iron-oxide dust into the skies over northern Utah County.

The dust is non-toxic, and the director of the City-County Health Department in Provo said it may temporarily irritate nasal and throat passages but cannot cause any serious or permanent health problems."Although it looks quite bad, it cannot be absorbed by the lungs," Dr. Joseph Miner said. "It can't cause systemic damage."

At a hastily called press briefing Friday morning, Geneva President Joseph Cannon said a seal on a steam line in the plant's open hearth furnace complex broke about 9:30 a.m.

The failure caused a loss of steam pressure to the waste heat boiler, which is a portion of the pollution control system at the open hearth.

The pollution control system was bypassed between 11:30 a.m. and 2 p.m. to allow workers to repair the line. While the system was bypassed, the open hearth sent its dust and smoke directly into the air without passing it through pollution control equipment.

The resulting orange cloud billowing from the open hearth smokestacks was visible for miles. By midafternoon a dull red haze had flattened out and hung over much of northern Utah County.

"In a steel plant there are an infinite number of things that can go wrong, and we have breakdowns all the time," Cannon said. "Usually it's not pollution control equipment. There was nothing to precipitate this. It was undetectable and unpredictable."

Shutting down the pollution control system was the fastest and safest way to fix the problem, said Jack Bollow, Geneva public affairs director. Halting the furnace operation while the repairs were occurring would have caused damage to the open hearth and could have endangered workers in the complex.

The breakdown was reported immediately to the Utah Bureau of Air Quality. Bureau Director Burnell Cordner said air quality regulations allow for such problems.

Geneva managers must submit a formal report on the incident to the bureau within five days. If the bureau determines the

breakdown was unavoidable, the company would not have committed any violation of air quality regulations despite its bypassing of pollution controls, Cordner said.

If poor maintenance or some other preventable cause is identified, Geneva could be judged guilty of a violation.

The breakdown probably could not have come at a worse time for Geneva Steel. Thursday night company officials attended a public hearing in Orem before the Utah Air Conservation Committee that drew 400 citizens.

Many of those who testified blamed Geneva emissions for health problems suffered by them and relatives.

The breakdown and the resulting iron-oxide cloud could cause more Utah Valley residents to join those calling for the steel mill's closure to improve the valley's air quality.

"If we could have arranged another time for this to happen we would have," Cannon said.