When it enacted the law in July 2008, California became the first state to ban artificial trans-fat in restaurants. Since then, trans-fat bans have been successful only at the city and county level, not at the state level.
Phase one of the law banned trans fats in oil, shortening and margarine used in spreads or for frying. Now restaurants must stop using oil with trans fat for cake batter, doughnuts and other items.
Food sold in sealed manufacturers’ packaging are exempt from the law. A law that took effect in 2009 required public schools to eliminate trans fat in cafeteria food.