PITTSBURGH - Bob Oesterling opened his tobacco store, Smoke 4 Less, in Clarion in 2010. Two years later, he started selling vaping products, and he opened a vaping wholesaler in 2013.

In that time, he says, he has had hundreds of customers quit using tobacco and start vaping.

Now, with Pennsylvania's Tobacco Products Act scheduled to take effect next Friday, he fears his entire business will go under.

The act puts a 40 percent tax on e-cigarettes and the liquid used inside them, as well as many products associated with vaping, such as cotton, batteries, chargers, wire, and coils.

Those products - which customers could buy tax-free at a regular store - make up about 50 percent of Oesterling's sales.

On Tuesday, Oesterling filed a petition with Commonwealth Court against the state Department of Revenue seeking a declaratory judgment that the tax applies only to the e-cigarette and the liquid used with it.

A spokeswoman for the department said she needed additional time for research and could not comment.

The act defines electronic cigarettes as the devices used for inhalation, as well as the liquid placed inside them. It does not name individual components.

Because of that, the petition alleges, the attempt to tax those items is an improper effort to expand the legislative definition and a violation of the separation of powers. It also claims that it is a violation of the clause requiring taxes to be uniform on the same class of subjects, as well as equal protection and due process.

"The whole vaping industry is up in arms over this," said Andrew Salemme, Oesterling's attorney.

More than 70 vaping stores have closed since the first part of the act went into effect Oct. 1, he said. Seventeen of those, Oesterling said, were customers of his wholesale business.

"Everybody is going to online sales instead of brick-and-mortar stores that employ people," he said.

In addition to the 40 percent tax on the wholesaler, the Tobacco Products Act requires that retailers pay a 40 percent tax on the inventory they keep in their stores.

Oesterling said he believes the state implemented the huge tax on vaping because the number of cigarette smokers has decreased substantially since vaping began to take hold. Fewer smokers means less money the state gets from the Tobacco Master Settlement Agreement.

"They're trying to tax us out of business," Oesterling said. "The vaping industry has reduced those numbers of smokers drastically."

In November, the Allegheny County Board of Health approved a prohibition on the use of e-cigarettes in workplaces, schools, government buildings, sports stadiums, and public indoor spaces.

Oesterling said vaping is a healthier alternative to cigarettes, citing an April report by the Royal College of Physicians and other information from Public Health England.

"But the FDA is trying to persuade the public otherwise," he said.

Oesterling said he smoked two packs of Marlboros a day for 35 years. Two years ago he decided to give vaping a try. He said he has never felt better.

"I can smell. I can taste my food again," Oesterling said.