Is it ok to buy used aluminum cookware?
Aluminum salts from cookware can leach from the pot into the food being cooked, particularly if it is acidic, causing a number of unpleasant symptoms.
If you buy used cookware at flea markets or thrift shops, check the label carefully and watch out for non-anodized aluminum. Non-anodized aluminum pots are usually heavy and look like they are pressed from a single piece of thick metal. The inside is the same color as the outside. Don't buy these.
Most aluminum cookware manufactured today is anodized. When a cookware label says it is made from anodized aluminum, it means that the aluminum was dipped into a hot acid bath that seals the aluminum by changing it's molecular structure. Once anodized, the aluminum will not leach into food. If you are considering buying aluminum cookware, call the manufacturer and see if it has some recycled content.
There are some brands of cookware that use aluminum for the base of the pan because it distributes heat evenly and is relatively inexpensive, and then line the pan with stainless steel or some other finish. Cookware containing aluminum is safe to use only when the aluminum does not come in contact with the food, but those lined with stainless steel would have the same leaching problem as any stainless steel cookware.