A state Senate committee has approved a bill to raise the minimum smoking age in California from 18 to 21. Assemblyman Paul Koretz is the bill´s author. He says the measure would reduce smoking among teen-agers by making it more difficult for them to buy tobacco products. If approved, it would make California the strictest state in the nation for tobacco purchases. The tighter age restrictions will make it more difficult for 12 to 17 year olds to buy tobacco, he says, because they´ll have to pass for age 21. Most smokers are hooked by age 20, he says, and this would reduce the number of lifelong smokers by encouraging young people to wait before taking up the habit.