LEAD IN CERAMICWARE
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CERAMICWARE: Lead-containing glazes are used in the ceramic industry and pottery, earthenware, bone china and porcelain. Lead glazes produce a smooth, shiny and sanitary surface that is pleasing to the eye and easy to clean. There are two reasons why lead may leach out of the glazes on ceramicware; one originates with the manufacturer and the other is the result of wear and aging of the dishes. At the manufacturer, after the glaze is applied to the piece, it is fired in a kiln. When ceramicware is fired properly (at a high temperature for a long period of time), the lead is sealed into the glaze and will not leach from the surface. However, if a glaze is incorrectly formulated OR if the item is improperly fired during the manufacturing process, hazardous levels of lead may leach from the glazed dishes into the food placed on them. Once a set of dishes that is lead safe is in the home, the glazes can begin to break down through use and damage and the lead can then leach out. Repeated cycles through the dishwasher, over years of everyday use, can also cause the glazes on dishes to break down, allowing lead to leach into the food placed on them. Cracks or chips that develop on the dishes are another source of leaching lead. Acidic foods such as orange or grapefruit juice, tomato juice, coffee or tea and tomato-based foods such as spaghetti sauce, wines and vinegar-containing foods cause more lead to leach from the glazes into the food than do non-acidic foods such as water or milk. More lead leaches into hot food than into cold food. Heating food on ceramicware in a microwave oven increases the rate at which lead leaches from lead glazes. DO NOT store food in lead-containing ceramicware. Imported ceramicware is more likely to leach lead than ceramicware manufactured in the USA. Often a new set of dishes arrives from the manufacturer coated with a fine lead-containing dust. Consequently, wash new dishes first with mild detergent, and rinse and dry them thoroughly before you test them. Although a set of dishes is purchased at the same time, the manufacturers cannot guarantee that all the dishes were produced or fired at the same time. It is possible that a few items in any given set of dishes may leach high levels of lead. Testing only one dish from a set is not necessarily representative of the set. Initially test about 10% of a set of dishes. For example, randomly select six dishes, bowls or mugs from a set of 60 pieces to test. For sets that are older, select pieces that have been used most often or have chips or cracks. If any of the selected items test positive for lead, consider testing all the pieces in the set and do not use those that test positive. If you own several sets of ceramicware, you should test the set used everyday or most frequently first. Method: Before you begin, be sure the dish is clean. Wash brand new (or never used) dishes with mild detergent, rinse and dry before testing. Activate a LeadCheck® Swab according to the Instructions supplied with the kit. Immediately rub the activated Swab over the surface of the dish while you squeeze the liquid out for 30 seconds. Be sure to rub over each colored glaze used in the pattern and any cracks or chips on the dish. Examine the Swab tip and or the dish surface for any pink or red color. Interpretation of results: If an unmistakabe pink color appears on the swab and/or on the ceramic surface, lead is leaching from the piece at a hazardous level. The pink or red color is not toxic and will not stain your dishes. After performing the test, wash it thoroughly with an all-purpose household cleaner. If no pink or red color is observed either on the dish or on the Swab tip, then a hazardous level of lead is NOT leaching from that dish. *LeadCheck® Swabs are a versatile and sensitive screening tool for the detection of lead on any surface. This applications note provides a suggested method to allow testing for a specific application. Additional information and help are available by calling 800-262-5323 or 508-651-7881.