Can pizza pollute? The Lewis and Clark City-County Health Board members aren't taking any chances.

The group unanimously ruled Thursday that a proposed commercial wood-fired pizza oven couldn't be fired up on poor air quality days.

Mike Hampton of Helena wants to open a wood-fired pizza restaurant at the old Arctic Circle on Helena Avenue.

The oven, which Hampton said is similar to one used in the Kalispell area, burns about a cord of cured hardwood per month.

But the model runs afoul of county air quality rules because there's no emissions data, says county sanitarian Tiffany Parliament.

There's no idea what sort of soot the oven may put out, she said, so the Environmental Protection Agency does not exempt Hampton's proposed model.

Meanwhile, proposed EPA air pollution limits are expected to get even tighter in the future.

"It is very difficult to prove this will not have an adverse effect on the public health," Parliament said.

Hampton said the top of the oven dome would be 1,000 degrees and hot enough to incinerate byproducts, much like a catalytic converter. Minimal haze would be emitted, he said.

Helena's air quality has greatly improved since the murky winter days of the 1970s, Hampton said, because fewer people burn wood.

"The little amount that my stove puts out isn't the difference that's going to put it over the edge," he said.

In fact, the county has only recorded seven "poor" air quality days since 2000 -- and those were due to forest fires.

Use of home wood stoves are prohibited on such days. On normal days, county rules set limits on emission, measuring opacity, or opaqueness. Department sanitarian Frank Preskar said that level is akin to "pretty thick smoke."

The health board can grant variances in cases of economic hardship, or if a heating system is temporarily out of service.

The board's decision probably won't have a huge impact on Hampton's operation.

He purchased two gas ovens, which can be used when the air quality is poor. (Parliament said Missoula's stricter air quality rules prohibit all wood-fired ovens, even with a gas option.)

And Hampton may buy a smaller pizza oven, which would meet EPA exemptions.

Health Board member Peter Donovan said he supported the unanimous decision because the owner had a second fuel source and poor air quality days are uncommon.

"Since those (poor air quality days) occur so rarely, I didn't think it would cause an undue business hardship on them," he said. "You might weaken the rule if you grant the variance."

A Flathead City-County Public Health official said they don't typically worry about such a source.

"It just seems like a small source," said acting health officer Joe Russell. "We wouldn't be concerned about regulating it in Flathead County."

Reporter Jason Mohr can be reached at 447-4075 or jason.mohr@helenair.com.