California Labor Code section 6404.5, the state’s smoke-free workplace law, prohibits smoking in “enclosed” workplaces, but this term is not defined in the law. While common sense may suggest that the existence of four walls and a roof makes a workplace enclosed, a long narrow place with an open front (found at some restaurants) can trap smoke in the back as effectively as if a front wall existed. Similarly, a patio surrounded by four high walls but open to the sky may still trap smoke, especially if the air does not move. Existing legal commentary would not consider these places “enclosed” under state law. Under such an interpretation, the state smokefree workplace law would not apply to these places.