More than 1.3 million pounds of a possibly cancer-causing chemical was released into the air at Hercules' Bacchus Works last year. State officials do not know whether it posed a health risk for residents.

State officials have been planning to monitor air quality near Hercules for two years, but it was never done. No testing is scheduled for this year.If air samples eventually are collected, there are no federal or state standards on which to base a safety decision for this chemical, methylene chloride.

Burnell Cordner, director of the Utah Bureau of Air Quality, said he does not know whether the emissions pose a health risk to the thousands of people living near the plant.

William Hayes, an environmental specialist for Dow Chemical USA, which makes the compound, said studies found exposure to methylene chloride causes cancer in certain laboratory animals. However, long-term studies of industrial workers exposed to high concentrations of the chemical have not shown an increased cancer rate.

"It means that for man it is considered a low-risk carcinogen. It is far less potent than benzene, asbestos or other chemicals," Hayes said.

Bill Hawkesworth, spokesman for Hercules, said company experts do not believe their methylene chloride emissions present a danger to the public.

Although the annual total is large, the chemical is emitted in a continuous flow of air at low concentrations, he said. Concentrations are dissipated even further before it reaches public property, he said.

However, he said Hercules is encouraging customers to purchase graphite produced by a new process that uses water instead of methylene chloride. About one-third of the company's customers have switched, but the rest are reluctant to change until graphite made with the new water-based process is proven suitable.

Richard Anderson, manager of environmental planning and operations at Hercules, said there are only two ways to control emissions of this chemical: build a massive air-pollution-control system or switch to the new process that doesn't use methylene chloride.