Most cookware in Canada is safe to use for daily meal preparation, provided it is well maintained and used as intended by the manufacturers. However, some materials used to make cookware can potentially enter the food we eat. Therefore, a review of current knowledge about the safety of cookware is useful.

Because aluminum is lightweight, conducts heat well and is fairly inexpensive, it is a popular choice for cookware.

Canadians normally take in about 10 milligrams (one milligram is one thousandth of a gram) of aluminum daily, mostly from food; cookware contributes only about one or two milligrams of the total. While aluminum has been associated with Alzheimer's disease, at present there is no definite link between this metal and the causes of the disease. The World Health Organization estimates that adults could consume over 50 milligrams of aluminum daily without harm, so there is little cause for concern.

Remember that during cooking aluminum dissolves most readily from worn or pitted pots and pans. Also, the longer food is cooked or stored in aluminum vessels the greater the amount dissolved into food. Leafy vegetables and acidic foods (such as tomatoes and citrus products) absorb aluminum most readily.

Since copper cookware conducts heat well, it allows for precise control of cooking temperatures. Brass, an alloy of copper and zinc, is less commonly used for cookware.

Small amounts of copper contribute to everyday health. However, large amounts of copper in a single dose or over a short period can be poisonous. It is not certain how much can be safely tolerated each day.

As a precaution, copper and brass cookware sold in Canada are coated with another metal. This prevents the copper from coming into contact with food. Small amounts of the coating can be dissolved by food, particularly acidic food cooked or stored for long periods in the cookware. Nickel is one of the metals used in coating. Anyone allergic to nickel may have a reaction to nickel coated cookware.

Coated copper cookware can lose its protective layer if scoured. Do not use badly scratched or uncoated copper cookware to cook or store food.

Stainless steel, an alloy of iron and other metals, is strong and resists wear and corrosion. Stainless steel is the most common material used for cookware in North America. Iron cookware is inexpensive and durable.

The metals present in stainless steel or iron cookware which may produce health effects are iron, nickel and chromium.

Iron is essential in producing red blood cells. Large amounts can be poisonous, but North American people are more likely to lack iron than to have too much. Iron cookware has been estimated to provide less than 20 per cent of total daily iron intake - well within safe levels.

Nickel is not poisonous in small quantities but can cause an allergic reaction. People who are sensitive to nickel can react to even trace amounts in stainless steel. Such people should avoid using stainless steel cookware.

Small doses of chromium, like iron, are beneficial but can be harmful in higher amounts. The safe intake range is about 50 to 200 micrograms (a microgram is one millionth of a gram) per day and most Canadians take in amounts in this range. One meal prepared with stainless steel equipment gives about 45 micrograms of chromium, not enough to cause concern.

Ceramics (pottery), enamel and glass cookware are easily cleaned and can be heated to relatively high temperatures. Ceramics used in cookware are glazed, which gives them a smooth surface; similar glazes are applied to metal, making enamelware. These glazes, a form of glass, resist wear and corrosion.

Any concern about hazards from glassware or enamelware comes from minor components used in their manufacture, or decoration. This material may include some pigments and lead. The likelihood of any potentially harmful material entering food is controlled through manufacturing techniques.

In Canada, the sale, advertising and importation of glazed ceramic ware used for food have been regulated since 1972. Glazed ceramic foodware is permitted to release only very small amounts of lead and cadmium. Glazed ceramic foodware from abroad and personally imported by Canadians may not meet the Canadian permitted levels of lead and cadmium. Some countries may not have the same strict requirements for glazed ceramic foodware.

For cooking and storing food, plasticware is lightweight and nearly unbreakable. Many items have been developed for use in microwave ovens, where metal cookware is not suitable.

Using plastic containers and wrap for anything other than their original purpose may cause health problems. The concern with wrap is that food may absorb some of the plasticiser (a material that helps make the wrap flexible). This is most likely to occur at high temperatures (like microwaving and with fatty or oily foods like cheese and meat. It is best not to use plasticware or plastic wrap in the microwave unless it is specifically labelled as microwave safe by the manufacturer. If you reuse items for storage, like dairy product containers, let the food cool before storing it in them, then refrigerate immediately.

Avoid visibly damaged or stained plastics or containers with an unpleasant odour. Do not heat or store food in plastic containers that were not intended for food.

Nonstick coatings applied to metal utensils prevent food from sticking to them and protect cookware surfaces. They are chemically inert, so even if some of the material is swallowed it would pass through the body harmlessly. The only time nonstick coatings are likely to pose any risk is if they are heated to temperatures greater than about 350 degrees C or 650 degrees F. This might happen if an empty pan remains on the stove. In this case, the coatings can give off irritating or poisonous fumes.

Health Canada/Sante Canada

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