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Artificial trans fat is formed during a chemical process that adds hydrogen to liquid vegetable oils to make them more solid, creating a "partially hydrogenated oil." Even eating small amounts of trans fats increase the risk for coronary heart disease by raising LDL (bad cholesterol) and decreasing HDL (good cholesterol). Studies predict that replacing trans fats with healthier fats and oils can prevent approximately 30,000 to 100,000 premature deaths each year in the United States.

In King County, food establishments may not use nor sell any product that contains partially hydrogenated oils. This restriction includes all foods, including but not limited to:

  • bulk products such as pancake mix.
  • pre-made items used in recipes such as graham crackers for crusts.
  • pre-made products such as frozen foods that are cooked in the food establishment, or bulk muffins or other products that are sold individually.

Any food made with partially hydrogenated oil contains trans fat. Partially hydrogenated oils are found in some shortenings, margarines, and liquid oils. The rule does not apply to products sold in the manufacturer’s original, sealed package (such as individually packaged chips, muffins, or cookies.)

An exception will be made if the manufacturer's Nutrition Facts Panel states there is zero or less than 0.5 grams of trans fat per serving.

Read the regulation and code

All food establishments that obtain their operating permits from Public Health - Seattle & King County are required to comply with the regulation to eliminate artificial trans fat.

Determining if your foods contain artificial trans fat

  • First, check the Nutrition Facts Panel. If the panel indicates no trans fat or less than 0.5 grams of trans fat per serving, you may use the product.
  • If there is no Nutrition Facts Panel, check the ingredient list to see whether any "partially hydrogenated" ingredients are listed. If the words "partially hydrogenated" appear, ask the manufacturer for a letter indicating the amount of trans fat grams per serving.
  • If there is no Nutrition Facts Panel and no ingredient list, obtain a letter from the manufacturer listing the amount of trans fat per serving.
  • Only use products with less than 0.5 grams of trans fat per serving. The information must be on the manufacturer's letterhead or other documentation from the manufacturer with company name and address. Keep the letter or other documentation to show a Public Health inspector if asked.

Common sources of artificial trans fat

  • Baked goods (cookies, crackers, cakes, pies, muffins, fried taco shells, tortilla wraps, and some breads, such as hamburger buns)
  • Toppings for baked goods and ice cream (sprinkles, chocolate chips, non-dairy whipped toppings, syrups, icings, and candy coatings)
  • Pre-mixed products (cake, pancake, and chocolate drink mix; pizza dough; laminated doughs)
  • Pre-fried or par-fried frozen foods (French fries, onion rings, fish sticks, chicken nuggets, frozen pie crust, frozen dough, egg rolls)
  • Nacho cheese sauce, salad dressing, non-dairy creamer
  • Bread crumbs and croutons. Note: these foods may be exempt from the trans fat regulations if they are served to customers in the manufacturer's sealed, original packaging.

Trans fat alternatives

There are many types of oils, shortenings, margarines, spreads and other products that contain no artificial trans fat. Talk to your distributor now about trans fat-free products, and experiment with non-trans fat products.

Trans fat that occur naturally

Small amounts of natural trans fats are present in some meat, milk and dairy products including beef, lamb and butterfat. It is estimated that naturally occurring trans fat makes up about 20% of the total trans fat that the average American consumes. The Board of Health's regulation addresses the use of artificial trans fats.

The regulation doesn't apply to pre-packaged foods

Pre-packaged foods sold in the original package are not affected by the legislation. Interstate commerce regulations prohibit these pre-packaged products from being included in the scope of the proposed legislation.

What to do about unlabeled products

Fresh, unprocessed agricultural products such as fresh vegetables, fresh eggs, and raw meat, poultry, and eggs do not require a label. Everything else needs some form of documentation. Check your kitchen and storerooms for unlabeled products. If you find an item without a label, ask your supplier to provide a label or appropriate documentation (described below).

If you are buying unlabeled baked goods or other freshly-made foods directly from the producer, a letter from the producer instead of a label is acceptable. The letter should contain the following information:

  • The producer's name, address and phone number
  • Item name
  • Serving size
  • Item ingredients, listed from heaviest to lightest

If the words "margarine," "shortening" or "partially hydrogenated [vegetable] oil" appear in the ingredient list, the letter must include the trans fat content per serving.

Choosing new products with 0 grams of trans fat

Manufacturers of prepared foods and mixes have been working hard to eliminate artificial trans fat. Many familiar brands are already made with 0 grams of trans fat. If your suppliers are not stocking 0 grams trans fat versions of the products you need, talk to them about making the switch as soon as possible.

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Not every fry oil or shortening is ideal for every purpose.
  • "Light/medium duty" oils include traditional oils such as canola, soy, sunflower, and olive oil. These oils can be used for salad dressings, marinades, sautéing, stir frying, and deep frying. When used at high heat, light/medium duty oils break down more quickly than heavy duty oils and fry oils that contain trans fat.

    If you deep fry with these oils, it's important to change oil more frequently.

    Soy and canola oils are often treated with an antioxidant (such as TBHQ). The anti-oxidant is usually paired with an anti-foaming agent (such as dimethylpolysiloxane) that further slows the breakdown of the oil. These additives make cooking oil more durable for restaurant use. Oils with additives may hold up a little longer in the deep fryer, but still require more frequent changing than heavy duty oils.

    You can get extend the fry-life of a low-cost light/medium oil by blending it with a small quantity of heavy duty oil. See "Understanding heavy-duty fry oils", below, for more information.

  • "Heavy duty" oils are good for extended deep frying over longer periods. (Under the right conditions, certain heavy-duty oils can last a week or more.) These oils differ in terms of flavor, cost, and stability. They are available as clear oil or creamy pourable shortening. Heavy duty oils and shortenings with 0 grams of trans fat will perform most like partially hydrogenated fry products. See "Understanding heavy-duty oils", below, for more information.

  • "Liquid butter substitutes," for griddle and pan frying. These are butter-flavored 0 grams trans fat shortenings and margarines (creamy and solid) that are much more stable than butter at high heat. Liquid butter substitutes may contain a chemical called diacetyl that may cause harmful lung exposure during cooking. Exposure to diacetyl can be reduced by switching to a butter-flavored substitute that contain less or no added diacetyl. More research is needed to determine how much diacetyl restaurant workers are exposed to.

"Choosing fry products that are right for you" was adapted with permission from the New York City Dept. of Health and Mental Hygiene.

If you used trans fat to deep fry before, you will find that the oil or shortening that you switch to may require more attention.

Every fry product has an approximate "fry life" that varies with the type of frying you are doing. Using any oil past its fry life creates unhealthy by-products. When deep frying, especially, be sure to monitor your oil carefully and change it as soon as it starts to break down. Here is what to look for:

  • Excessive darkening, foaming, and viscosity or thickness
  • Smoking
  • "Off" flavor and odor in fried food
  • Greasiness/loss of crispness in fried food

The signs of oil breakdown are the same no matter what kind of oil you fry in. Abusing or over-using fry oil gets you soggy, bad tasting and unhealthy food. So don't abuse your oil! Good fry oil maintenance is good business practice that customers will notice.

Begin by keeping oil in a cool place (and away from the light if it's stored in clear bottles). In the deep fryer, follow these guidelines:

  • Avoid unnecessary exposure to heat. Maintain a steady temperature between 325ºF and 375ºF; do not overheat. If you have a long break between periods of use (between lunch and dinner, for instance), allow the fryer to cool—but not too much, as repeated cooling and heating can also harm oil. A resting temperature of 280ºF is recommended. Be on the lookout for fryer "hot spots" that may cause burning or localized overheating.

  • Keep food crumbs out of the fryer. Remove excess breading and fat from food before frying, and skim out food debris after each frying. Fill fry baskets away from oil, to keep crumbs out. Never salt or season foods over the fryer.

  • Keep the fryer clean. Filter completely at least once a day, and keep the fryer spotless (daily cleaning is recommended). Rinse fryer thoroughly with a vinegar solution after cleaning, to neutralize detergent residue.

  • Control moisture. Dry fryer thoroughly after cleaning. Do not allow condensed moisture on the hood or fryer cover to drip back into the oil. Remove excess moisture from food before frying.

  • Cover fryer when not in use. This will limit contact with the air and keep particles out of the oil.

"Deep frying tips" was adapted with permission from the New York City Dept. of Health and Mental Hygiene.