Twenty-five years after environmental regulators starting insisting that steel mills and chemical factories clean up the acrid smoke that belched from their smokestacks, regulators have started cracking down on a new set of air pollution culprits: bakeries.
Federal and state environmental officials are drafting rules that will force large bakeries everywhere -- including at least three in Maryland -- to install "scrubbers" on their ovens' smokestack to remove the delicious, mouth-watering smell of baking bread.
The reason: Scientists recently discovered that the sweet aroma of cooking yeast is full of ethanol, which, when exposed to sunlight, turns into asthma-inducing ozone, said Carl York, chief of regulation planning for the Maryland Department of the Environment.
Mr. York said Maryland has drafted rules -- and expects federal approval by November -- to require the largest bakeries to reduce their ethanol emissions by at least 70 percent.
The rules are part of a federal drive to cut 15 percent of the ground-level ozone pollution in urban areas like Baltimore by next year.
But, bowing to the popularity of bread and bread aromas, the state has exempted the hundreds of small corner bakeries, he said.
Even some of the larger producers -- such as the H&S bakery in Fells Point -- have won exemptions because they are old, because it wouldn't be cost effective to install expensive scrubbers or because they aren't major polluters, he said.
Studies of bakery smokestacks around the state showed that large amounts of ethanol reach the air only when certain kinds of bread are being baked, Mr. York said.
"It really depends on what kind of bread you're making. It's not pizza, or doughnuts or cookies. Those have a relatively low yeast content and a very low ethanol emission rate. But white bread has a very high yeast and ethanol content," Mr. York explained.
Two of the state's biggest bread bakers -- specialists in yeasty, ,, spongy breads -- have already started sanitizing their smells.
Baltimore-based H & S. Bakery Inc. has added a $200,000 ethanol incinerator to its biggest smokestack at its Moravia Road hamburger bun bakery.
And Landover-based Giant Food Inc. last month won permission to use its first-of-its-kind ethanol condenser to pull the ethanol out of the smoke from its largest Silver Springs bakery smokestack.
Managers at Schmidt's Bakery just north of the city line are in the midst of deciding how they can clean up their emissions before the autumn 1996 deadline, Mr. York said.
Schmidt's Fitch Lane bakery, which makes 50,000 tons of bread annually, emits more ethanol than any other bakery in the state -- 117 tons a year, Mr. York said.
"That is a good-sized, major source," he said. "Not like General Motors, but like a printer."
Although officials at Schmidt declined to comment, managers at the other affected bakeries said they went grudgingly along with the new rules, which they complained will increase their costs while doing little -- if anything -- to clean up air pollution.
Giant had only received compliments about its bakery's smells, said Mark Coffin, Giant's director of bakery and dairy operations.
"It's a great smell. . . . The smell of baking bread is like mother, applie pie and baseball."
But Giant's new condensing machine, which removes about 70 percent of the bakery's 45 tons of annual ethanol emissions, "hasn't eradicated the smell totally."
Because cakes, cookies and other non-yeasty items are about one-third of Giant's weekly output of 1.5 million pounds of baked goods, Giant's Silver Spring neighborhood still smells pretty good, he said.
William J. Paterakis, vice president of H&S, said he believes the regulations are misdirected.
His family owns 10 bakeries throughout the East Coast, and has had to install three ethanol burners for a total cost of nearly three quarters of a million dollars. The incinerators cost about $40,000 a year to run, he said.
At his Baltimore bakery, where H&S makes the hamburger buns served at McDonald's and Burger Kings throughout the region, the incinerators add about a penny to the cost of a dozen hamburger rolls while reducing only a tiny amount of ozone pollution, Mr. Paterakis said.
While they eliminate 95 percent of the ovens' airborne ethanol, the incinerators themselves pollute since they use a natural gas-fueled flame to burn up the ethanol, he noted.
The MDE estimates that the Moravia Road bakery emits 38 tons of ethanol a year, and that its new incinerator will cut those emissions by 80 percent or nearly 31 tons.
The rules, he said, will "have little impact on the ozone, but create enormous amounts of paper work and environmental consultant fees."
Mr. Paterakis said he was happier with Clean Air Act rules that are forcing him to change his fleet of delivery trucks to less-polluting fuels, such as compressed natural gas. He said he will begin converting his fleet by 1998.