DEAR DR. BLONZ: I hadn't thought of this before, but now I am concerned that the cooking spray I use contains dimethyl silicone and a propellant. I use it occasionally for greasing baking pans, but I don't use it for everyday cooking. Is this something I should be concerned with? -- P.M., via email
DEAR P.M.: Nonstick cooking sprays are based on a vegetable oil, such as corn, soy, canola, olive, coconut or avocado. Also among the ingredients can be lecithin, an emulsifier that keeps the ingredients from separating, and an antifoaming agent, such as dimethyl silicone, that facilitates the desired formation of the nonstick film. The container will have either a mechanical pump or a gas propellant under pressure. These sprays keep food from sticking to the pan by forming a thin film between the cooking surface and the food.
Rubbing a small amount of oil on the pan can also prevent food from sticking, but the coating action of the cooking spray tends to be superior, uses less oil and makes for easier cleanup. Another positive is that a one-second spray application -- sufficient to cover a 10-inch skillet -- will contain less than 1 gram of fat.
Ingredients should be clearly listed on the label of formulated cooking sprays so you can choose a product that contains no more than the basic components. There is no evidence that the ingredients in these products are unsafe in the small amounts used. Always shake well before using cooking spray to mix the ingredients thoroughly.
A potential safety issue with all aerosol sprays is their compressed-gas propellants. Some sprays include flammable hydrocarbon gases, such as propane, butane or isobutane, and should be used only on cold surfaces -- never around flames. Check the container for the required warnings about flammability and cautions about use and storage.
There is another option available: refillable sprayer/mister bottles specifically designed for cooking. While they cannot produce as fine a mist with as little oil as the high-pressure sprays, they solve the problem of how best to dispose of empty containers. If you opt for a refillable spray bottle, consider experimenting with different oils. Be sure to avoid unfiltered oils with particulate matter that can clog the nozzle. Also avoid oils with flavors that can affect the foods being prepared.
Finally, remember that oils have a shelf life. Clean refillable spray bottles periodically with warm water and detergent and allow them to air-dry completely before refilling.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.