Smoke-free workplaces have become so commonplace that the exceptions stand out as uncomfortable places for the approximately 75 percent of Mainers who don’t smoke. But a bill that would take smoking out of restaurants has an even better reason to snuff out cigarettes: the health of restaurant workers.

The bill has bipartisan support and a mountain of data behind it. In short, it argues that studies showing that nonsmoking restaurant workers are 50 percent more likely to die of lung cancer than other nonsmoking employees and the association of secondhand smoke with heart disease and respiratory illness are reasons enough to restrict smoking. Considering the lengths to which employers must go to protect employees from on-the-job hazards, a smoke-free workplace is a matter of common sense.

Protecting patrons, including children and people with medical conditions such as asthma, should also be of prime concern and gets at one of the reasons that restaurants have not already become smoke-free. Restaurant owners, naturally, have noticed the number of people who smoke after a meal and did not want to lose these customers. Now, however, they have evidence from more than 200 cities that show not only has there been no economic harm from the change but, in many cases, smoke-free restuarants have found their business increasing.

That’s not so surprising, really. Smokers find they can wait an additional 20 minutes — until they are outside — before lighting up and nonsmokers who did not patronize a restaurant before now could. More importantly, the cleaner air in these restaurants had measurable positive effects on some workers’ respiratory symptoms in as little as four weeks after the no-smoking signs went up.

The one sticking point with the this legislation was how it would distinguish between restaurants and that final bastion of the nicotine haze, the bar. Many places are both bar and restaurant, and trying to stop smoking in one part of a room or rooms and not in another is an enforcement nightmare. Fortunately, legislators found a simple solution found in state licensing requirements. Licensed lounges, taverns and hotel lounges, which do not allow minors unless accompanied by parents or guardians, easily fall into the bar category and would remain exempt. All other establishments would no longer allow smoking.

Smokers who worry that bars will be the next target of a smoking restriction probably are justified in their concern. The restaurant bill, which has been submitted several times before, stands a good chance this session because the public has come to accept and even expect these restrictions. Timing is everything in lawmaking, and the time is right to end smoking in restaurants.