IF YOU WORK IN or around a school kitchen, there's a new caution out about cooking with butter-flavored oils or butter substitutes.

Basically, artificial butter flavoring, called diacetyl, might hurt people who breathe it while they're cooking, according to the Washington state labor department. Manufacturers add diacetyl to foods, including cooking oils and butter substitutes, cheese, flour mixes and shortening.

It's when the chemical gets into the air that it might hurt people's lungs. More research is needed to tell how much diacetyl food workers are exposed to and whether it's harmful.

What can you do about this? Check labels for "diacetyl," "butter flavoring" or "artificial flavoring." Seal containers when you're not using them. Work with your local union to reduce exposure by substituting butter-flavored oils with natural products. Your union also may be able to work with the district to improve ventilation.

For details, go to the National Institute of Occupational Safety and Health (NIOSH), www.cdc.gov/niosh/topics/flavorings, and the Occupational Safety and Health Administration (OSHA), www.osha.gov/dsg/guidance/diacetyl-guidance.html.