Michigan State University Extension
Preserving Food Safely - 01600817
Galvanizing is the process of electrolytically coating iron metal with zinc, which protects the iron from rusting. Zinc is one of several heavy metals which can be toxic if consumed in large quantities. When acid foods (fruit juices, tomatoes, pickles) are placed in galvanized utensils of when meats or vegetables are cooked in galvanized containers, toxic amounts of zinc can brought into solution. Numerous reports of zinc poisoning can be found in the public health and medical literature, and essentially all of them relate the illness to the type of utensils used in food preservation. Symptoms of zinc toxicity are fever, nausea, vomiting, stomach cramps and diarrhea in three to twelve hours following ingestion.
Galvanized utensils (some types of old refrigerator shelves for outdoor grilling, galvanized trash cans for quantity cooking, etc.) should never be used for food preparation or preservation.