Calabasas, Calif. ? One of the strictest tobacco bans in the nation went into effect in the Los Angeles suburb of Calabasas on Friday, making smoking off limits in public places where someone else might be exposed to secondhand smoke: indoor businesses, outdoor businesses, parks, outdoor cafes, even apartment building common areas.

California air-quality regulators declared secondhand smoke a toxic air pollutant earlier this year.

Hotels can still allow smoking in up to 20 percent of their rooms, and smoking can be allowed in approved designated areas at shopping malls and workplaces in the upscale city of 23,000 residents. But if a nonsmoker asks a smoker to stop, the smoker must snuff it or face a possible fine in the hundreds of dollars or even a lawsuit.