A new law being mulled in Providence would tell smokers to butt out.

Rhode Island's capital city is considering an ordinance that would prohibit smoking throughout the downtown, a ban that an advocacy group says is the most wide-reaching one it's seen.

The ban would improve the quality of life for residents and visitors, according to proponents, but some business owners are concerned it could actually drive away customers.

The proposed ban would apply to non-enclosed sidewalks and other pedestrian areas, including alleys, that are accessible to the public anywhere in downtown Providence. Smoking would only be allowed in private residences and vehicles. Smokers who break the law could be fined up to $250.

"I haven't heard of anything quite like that before," said Bronson Frick, associate director for Americans for Nonsmokers' Right, a national nonprofit organization.

Because secondhand smoke is such a nuisance, Frick said, many cities have taken steps to address it in some form, often by requiring smokers to stay a minimum distance away from business' doorsteps. But no city that Frick was aware of has a comprehensive ordinance like the one being proposed in Providence.

The city banned smoking indoors in businesses including bars and restaurants in 2005.

In February, Boulder, Colorado, expanded its existing smoking ban to include all outdoor recreation areas and parks as well as the city's business improvement district, an area in downtown covering several blocks.

The Providence smoking ban would cover more area and prohibit smoking in all of downtown, an area that is defined by the city as about one square mile.

City Council President Luis Aponte said the ordinance was submitted at the request of several downtown property owners who've received complaints from tenants about smokers in front of businesses. Aponte is one of two sponsors of the legislation.

"Property owners were getting complaints from their tenants that as they entered the building they had to pass through this labyrinth of smoke," Aponte said.

Former Providence Mayor Joseph Paolino, who owns several buildings in downtown Providence, has taken credit for the proposal.

Paolino said ever since the city banned smoking in parks and in Kennedy Plaza, in the center of downtown Providence, smokers have been congregating in front of his nearby properties.

"Look how filthy the sidewalk is. Walk through there, you'll get the secondhand smoke," Paolino said.

The ban would also prevent people from loitering in front of his buildings, he said.

Though nobody on the council has opposed the ordinance, some business owners are concerned the ban would drive away customers who smoke.

"It could put me out of business," said Anthony Bottone, who owns the Olde Smoke Shoppe, a tobacco shop in the heart of downtown.

But Bottone is concerned about other businesses as well. Smokers who can't light up outside of bars and restaurants downtown might choose smoker-friendly neighborhoods instead, Bottone said.

For now, the city's law department is evaluating the ordinance, a spokesman for Mayor Jorge Elorza said.

Public hearings would be held in September, when the city council reconvenes.