Bars, restaurants and businesses became smoke-free early Tuesday, making Rhode Island the seventh state in the nation to ban puffing in most indoor public places.

The smoking ban went into effect at midnight Monday even as some lawmakers and bar owners were mobilizing to revise it or challenge it in the courts. Rhode Island joins California, Connecticut, Delaware, Maine, Massachusetts and New York.

The law covers thousands of bars and restaurants, and all indoor workplaces. But it extends the deadline to Oct. 1, 2006, for bars that have 10 or fewer employees and groups formed as private social organizations, such as the Veterans of Foreign Wars or Knights of Columbus.

Gambling centers Lincoln Park and Newport Grand, which are major state-revenue makers, are exempt from the ban. Those facilities already have some smoke-free areas.

Despite the exemptions, no-smoking advocates say society’s attitudes have shifted in favor of outlawing smoking in indoor spaces, as people have learned about the health dangers of tobacco and second-hand smoke.

“It’s an idea whose time has come in Rhode Island,” said Robert Marshall, spokesman for the state Health Department, which is charged with investigating violations. The Health department reports that 200 Rhode Islanders die annually from second-hand smoke.

Smokers at the Green Room, a pool hall in Providence, greeted the smoking ban with sighs of resignation. Ray Marotto, however, said he welcomes the law because it will help him cut down on his habit.

“Anything you can do to help people stop smoking (is good),” the 58-year-old Cranston resident said. “It’s such a rotten habit, but every time I quit, I balloon up to 220 pounds and go back again.”

The Rhode Island Hospitality & Tourism Association has polled its membership about a smoking ban for the past 17 years. Most of its more than 500 members had opposed the law until last year.

Lisa Doucet, the association’s spokeswoman, said she believes hotel, bar and restaurant owners changed their opinion because consumers changed theirs. “We believe a smoke-free environment is what the marketplace is asking for,” she said.

Some disagree that residents want the law. Rep. Joseph Faria, chairman of the House Labor Committee, has introduced a bill that would exempt neighborhood bars from the law. Faria said tavern owners have told him they stand to lose up to 30 percent of their business.

“I quit smoking three years ago. I don’t want to go into an establishment where people are smoking, but I don’t believe we have the right to take away something from places that’s allowed it” until now, he said.