Lead in stoneware and crystal — Harmful?
Originally Published: April 20, 2001 - Last Updated / Reviewed On: September 14, 2012
I have purchased a set of stoneware dishes for a friend for Christmas, but my family has told me that stoneware (even when microwave and dishwasher safe) can be harmful due to a high lead content. Is this true of all stoneware dinnerware? I would appreciate any information on the subject. Thanks!
We received a 24 percent leaded crystal decanter from Poland as a gift. We would like to use it for a liquor decanter. Is it safe? Are we in danger of lead poisoning?
Indeed, according to the Centers for Disease Control and Prevention (CDC), there have been cases of lead poisoning stemming from the use of stoneware and terra cotta. Usually, the culprit is a lead-based glaze that's applied to decorate and seal tiny porous openings on the surface of various types of stoneware. Cases of lead poisoning from the use of stoneware most often occur when the dishes are:
- Highly decorated: Especially when designs appear to have been painted on top of the glaze or when the glaze has deteriorated. Discard or don't use any dishes that show signs of glaze corrosion for food preparation or serving.
- Hand crafted: This increases the likelihood that glaze was made, applied, or fired (heated in a kiln to fix it to the dish) improperly.
- Antique: If any of your stoneware pieces are heirlooms, use them for display instead of dinner. The older your stoneware, the more probable it is that it contains lead due to lack of past regulation.
- Bright orange, red, or yellow: Lead is often used to maximize the intensity of these colors when applied to pottery.
- Stamped with a warning label that indicates the piece of stoneware is intended for decorative purposes only.
The U.S. Food and Drug Administration (FDA) recommends that ceramic dishes imported from China, where manufacturing practices may not be as carefully regulated, be vigilantly monitored for lead content. The Environmental Defense Fund web site lists Chinese ceramic dish manufacturers who meet U.S. safety standards. It also contains info about What You Should Know about Lead in China Dishes that names manufacturers and specific china patterns that use lead-free glaze.
For reader number two (last, but still leaded), beverages — alcoholic or not — must not be stored in crystal decanters that contain any lead because this mineral can leach out into the drink. The FDA’s limits for safe lead consumption are set to 250 μg/L of blood for adults, but storing liquor in a leaded container can introduce lead concentrations of up to 21,530 μg/L of liquor. Acidic liquids, such as fruit juice or vinegar, increase the leaching effect. Regular use of leaded crystal glassware is not recommended, particularly for children and pregnant women (because of lead's harmful effects on fetal development, such as learning disabilities and developmental delays). No amount of boiling, washing, or heating can eliminate the presence of lead in stoneware.
FYI, although it is possible to get lead poisoning from dishes and crystal, it's much more likely to be exposed to this mineral through lead-based paint. Lead particles can be released into the air and inhaled in the following scenarios:
- Exposure on-the-job, which the CDC estimates causes 95 percent of lead poisoning cases among adults. At risk folks include painters, ironworkers, or other laborers, who repair or demolish steel bridges, railways, and storage tanks coated with durable lead-based paint.
- Living in homes built before 1978. About 80 percent of all homes in the U.S. may contain lead-based paint. Residents are exposed to lead when these homes are renovated or when the paint peels or chips.
Children are more susceptible to experience lead poisoning because their bodies absorb lead more easily, and their developing nervous systems are more quickly and permanently damaged by the effects of lead. Health officials estimate that between 5 and 10 percent of American children have harmful amounts of lead in their blood. Children who don’t get adequate nutrition are significantly more vulnerable to the effects of lead.
At high concentrations, lead poisoning can cause seizures, coma, and death. Symptoms of low to moderate levels of lead poisoning include:
- Decreased attention span
- Hearing loss
- Behavioral and emotional problems
- Slowed growth
- Reading and learning disabilities
- Stomach pain
Because these symptoms are vague and easily mistaken for other problems, the American Academy of Pediatrics recommends that children be routinely screened. In fact, some states have mandatory lead screening for young children. Since lead is stored in children's bones, building up over time to toxic levels, prevention and early detection of lead poisoning is crucial. A few drops of blood taken from a fingertip in a health care provider's office can be used to detect lead poisoning in its early stages, before symptoms and irreversible damage appear.
Lead test kits that can detect the presence of lead in drinking water, paint, dishes, or other surfaces are also available for sale on the Internet for about $10 – $50. Some kits contain chemicals that turn color when exposed to lead particles, while others allow you to collect samples and mail them back to a lab for testing. The Occupational Safety and Health Administration (OSHA) offers a description and evaluation of some of the more popular lead home test kits on their web site. Additionally, NYC residents can test their drinking water for free by requesting a free lead test kit through NYC 311.
Some of the most beautiful pieces of stoneware are also the most dangerous to use due to their high lead content. It’s best to consider these pieces decorations, not dishes, unless they pass a lead test.