Food – Containers & Cookware
Did You Know?
- For much of recorded history, food has been contaminated by toxic metals in cookware, containers, and dishes. And since the widespread use of plastic food containers, food has been contaminated by chemicals leaching from them.
- Metal cans are often lined with toxic plastic films made with BPA and PVC.
- Some fast-food wrappers can leach Teflon™-like fluoropolymers into food. Teflon™ cookware coatings vaporize when exposed to high heat and cause symptoms in people similar to flu. The fumes can kill pet birds and cats.
- Cooking with aluminum foil can leach the metal into food cooked in it, particularly if the food is acidic or spicy.
Contaminated Containers, Cookware, & Dishes
The history of human nutrition is scarred with examples of people contaminating food by storing and cooking it in contact with toxic heavy metals.1
Hazardous effects of lead have been observed through much of recorded history. An Egyptian text thousands of years old noted lead could be fatal. The Greek physician Hippocrates described symptoms of lead poisoning as early as the 5th century BCE, including lost appetite and weight loss, colic, pallor, fatigue, and nervous spasms. Damaged vegetation was observed near ancient smelting sites. It was also observed that cows and horses could not be pastured near lead mines without increased illness and death.
History of the Roman Empire described acute toxicity to lead miners and metal smiths. In the aristocracy, loss of intelligence, insanity, sterility in men, and infertility and stillbirths in women were all attributed to lead consumption, with some historians believing lead eventually contributed to the fall of the Empire itself.
During the Roman Empire, lead had many uses. It provided plumbing conduits for some of the first and largest modern water supply systems in the world. Lead-based pigments were employed in cosmetics for the aristocracy. However, one of its other fundamental uses was to cook wine in lead containers; this was preferred to other materials because “lead sugar” (lead acetate) acted as a sweetener. And other Roman lead-containing cookware and pottery used for food were common.
Pewter tableware was made of tin and copper, often mixed with other metals antimony, zinc, bismuth, and in lower-quality versions, lead. Pewter was used by the Egyptians and Romans before the Common Era. In Middle-Age and Renaissance Europe, and later in the American colonies, pewter tableware, mugs, and tankards were widely employed. According to one source, lower-grade Medieval European pewter could contain between 10 and 75% of this toxic heavy metal, which would leach into food that came in contact with it.2
Bronze cookware from before the Common Era directly exposed food cooked in it to the metals it was made with. Bronze is a copper alloy. Its predominant co-metal is tin, but it often appeared with other metals, either intentionally to enhance its quality, or as contaminants. These included lead.
Copper from bronze could leach into food cooked in it (particularly salty or acidic food). While copper is essential for human nutrition in small quantities, it is harmful if over-consumed. It could also carry a bad taste into food. Verdigris, the greenish oxidation that taints copper, is outrightly poisonous, and would also find its way into food from unclean cookware.
Brass was another copper alloy sometimes used for cookware; its main additive was zinc. Some versions included other metals though, such as lead and arsenic.
As copper food vessels became more common in the 18th century, they were lined with tin to prevent problems associated with copper leaching. However, poor quality tin could also be contaminated with lead. Further, the tin lining would eventually wear away, and the cookware would have to be retinned, again sometimes with lead contaminant.3
Lead solder was heavily used as a sealant for the first tin cans, circa 1810, which also leached into food.4 Evolving canning technology greatly reduced, but did not eliminate, lead used in can sealing until the late 20th century. In the U.S., metal solder in cans was not consciously targeted for removal until 1979.5 Over the next 12 years, the domestic canning industry voluntarily switched to lead-free technology. By 1991, the industry had completely eliminated lead use. Even then though, lead-tainted cans were used for about 10% of canned-food imports. The U.S. Food and Drug Administration did not actually outlaw lead solder in cans until 1995.6
Food-containing pottery was, by necessity, manufactured with glazing to render it non-porous. In many cases, lead-based glazing (that could leach into food) was the material of choice, and lead pigments were also used as colorants. Toxic colorants other than lead in frequent use included: cadmium; copper oxide and copper carbonate; chromium oxide; iron chromate; manganese dioxide; selenium; and uranium oxide (which is radioactive as well as poisonous). “Potter’s disease” was a common name given for chronic lead poisoning to clay workers who used lead glazes.7
Chronic exposure to lower doses of lead was not really understood until the 20th century. Manifestations can include: high-blood pressure, heart disease; death; cancer; lowered intelligence, attention-deficit/hyperactivity disorder, and behavioral problems in children; increased levels of low birth-weight babies, premature births; spontaneous abortions; lowered fertility; and increased kidney dysfunction.8 Lead is a persistent bioaccumulative toxin, and there is no completely safe dose.
While these foolish past risks of toxic metal exposure can be condemned, they can to some extent be understood by the lack of scientific knowledge. Such rationalizations cannot be made today. One would assume that with these tragic precedents, our society would be wary. However, lead and other heavy metals are still found in some modern containers and cookware, as well as legacy ware and antiques. Worse, other potentially dangerous metals, chemicals, and plastics have also found their way into most modern kitchens.
Ceramics and Glass – This class of food containers can be rated as both the best and worst. At their best, ceramics and glass are inert and contain no harmful substances that can leach into food. However, for thousands of years, lead glazing and heavy-metal pigments have been used worldwide in ceramic dishware, serving ware, and pottery used for food storage.
The U.S. Food & Drug Administration has enforced ceramic safety regulations for lead since 1971, with even more advanced regulations in place since the late 1980s. These rules still allow the metal to be used in the glazings and pigments, but require the metal to be ‘baked in’ to the material so that it does not leach into food in more than minute quantities.
California’s “Proposition 65” regulations (initially started in 1986 by an initiative election to make knowledge about toxic chemicals in consumer products available to the public) have even stricter criteria for lead leaching. State rules address dishware, glass, and ceramic mugs for lead content in the material as well as in exterior decorations. Either lead levels must be prescriptively low, or the product or product packaging must carry a (yellow-triangle) warning that the product does not meet Prop 65 standards. Since California is the largest consumer market in the U.S., its lead regulations are the de facto standard in America. Some manufacturers go even further to manufacture no-lead and low-lead products due to health concerns.
However, legacy and antique materials that are more likely to be contaminated still exist in large quantities. These older products, as well as some hand-made products, have a higher chance of leaching lead, sometimes at dangerous levels.
The bottom line is: unless you purchase low-lead/no-lead products, there are increased levels of risk for lead intake.
Stainless Steel – This is another relatively benign food-compatible material. However, it is not inert. While less of a concern than metal materials such as aluminum, stainless does not rust because it contains chromium (18%) to prevent rust, as well as nickel (up to 16%) to make it shinier. Both can leach into food, particularly under the stress of lengthy heat cycles or acidic food.
While the amount is rarely if ever acutely toxic, about 10% of the public is allergic to nickel, with dermatitis being the most common reaction. This reaction is more prevalent in women.
A 2013 study by Oregon State University showed that nickel from stainless cookware leached into (naturally acidic) tomato sauce at levels that could affect people sensitive to it when it was cooked for 6 hours.9 Chromium also leached, though at levels not expected to be harmful.
Still, the study noted that exposures from these metals in cookware could combine with metal exposure from other sources to contribute to a higher level of ingestion.
To avoid nickel in stainless cookware and eating utensils, look for the rating that notes the percentage of metals in the product. You will see the number 18 (standing for 18% chromium), followed by /16, /10, /8/ or /0 (standing for the percentage of nickel). The 0% nickel rating really means no more than 0.75%, but this is still a dramatic reduction compared to other products with the same material. A 0% nickel product will generally not shine as bright as products with a higher percentage, but this should not diminish it functionally.
Silicone – Food-grade silicone products are smooth, lightweight, water- and impact-resistant, and can be manufactured to be air tight and easy to clean. They can include: bottles; dishes and cups; storage containers; and even sealable bags similar to plastic. Most studies show silicone either does not leach its constituent chemicals into food, or that such leaching is not significant or dangerous.
Some molded products contain cheap fillers that have been known to smell when heated. This is indicated by a white gel-like substance that appears when the products are squeezed. So purchasers of silicone cookware should look for higher-quality products. Also note that though products are in widepread use, some chemically sensitive people react negatively to them.
Ton Bangkeaw /Shutterstock.com
Metal Cans and Containers – BPA is not just in receipts. It is also in the resin that lines many canned products, as well as the plastic liners in many metal bottle lids. While these linings prevent metal exposure to food, they leach phenols instead.
Some food manufacturers have changed to alternative resins for can liners. However, they are either not safe, or their safety is unknown. More dangerous resins include vinyl (with PVC) and acrylics (with styrene), both of which are carcinogens. While other alternatives such as polyester and plant-based resins are more benign, they may include toxic additives that are not listed because of the proprietary nature of these commercial products.10
The following suggestions will help you more safely use container products.
1. Limit the canned food that you eat. Live food is healthier than processed food anyway.
2. Find out if products that you purchase have phenol in the containers. This may require phoning the companies or referring to their Web sites. The state of California has compiled a Web site list of processed food companies and their container policies (see the Sidebar in this story).
3. Rinse canned foods, which will limit phenols and other liner chemicals that leach into them, as well as undesirable nutritional additives such as salt and sugar.
4. Never heat food in a can. Transfer it to a proper cooking container.
Aluminum Foil – Aluminum is neurotoxic, and excessive amounts of aluminum can adversely affect health. Cooking with foil can leach aluminum into food cooked in it, particularly if the food is spicy or acidic.11 Using foil to store cold food has less risk, but even then, acidic foods and foods stored for longer periods of time are vulnerable to leaching if they are wrapped in it.
Plastic Containers and Film – There are 7 main types of plastics that food and liquids are commonly sold and/or stored in. Many of these have toxic additives that can leach into the products, even if the plastic resins themselves are relatively safe. In most cases, the additives are not disclosed, as they are trade secrets of container and film manufacturers. Below is a quick review of the major plastic types, with their recycling codes that make reuse easier, their respective concerns regarding leaching, and which ones to avoid whenever possible.
Polyethylene Terephthalate (PET) – Common uses include: soda, condiment, and sports-drink bottles; and single-use water bottles. The toxic metal antimony, which can cause anemia, gastrointestinal and heart problems, and muscle and joint pain, is used in this material’s production, and can leach into food products, particularly in the presence of heat or sunlight.12 Also, the longer a product is stored in PET containers, the more likely that leaching will occur.
Reuse of PET containers should be avoided, as the more degraded this plastic becomes, the more likely it is to leach.
High Density Polyethylene (HDPE) – Common uses include: milk jugs; food and beverage containers; detergent bottles; cosmetic bottles; cereal-box liners; and many kinds of bags. While generically considered one of the safer plastics, additives can leach estrogenic chemicals into food under certain conditions.13
Polyvinyl Chloride (PVC) – Uses include some types of food wrap such as shrink wrap, and clear food packaging. PVC is considered the most toxic of all common plastics. It is a developmental and respiratory toxin, and can be toxic to internal organs. When used as food packaging, it usually contains phthalate softeners that are endocrine disruptors. Even though some PVC packaging has a recycling arrow on it, do not recycle. It can contaminate other plastics in batch recycling programs. Avoid whenever possible.
Low Density Polyethylene (LDPE) – Common uses include: produce bags; wrap; plastic trays; and snap-on lids. Similar to its chemical cousin HDPE, it is generically considered one of the safer plastics, but it can leach estrogenic-chemical additives under certain conditions.
Polypropylene (PP) – Common uses include yogurt, margarine, and deli containers. This material is generically considered the safest of common plastics for food storage because it has a high tolerance to heat, but there is no certainty of what additives have been used without transparency from the manufacturer.
Polystyrene (PS) – There are two types of this plastic used to package food. Extruded polystyrene creates more rigid containers used in applications such as yogurt cups. Expanded polystyrene foam is used in a wide array of applications such as: self-insulating coffee cups; disposable plates; take-out trays; and supermarket meat trays. Among its more toxic constituent chemicals are styrene and (to a minimal degree) benzene, both carcinogens that can leach from the material, particularly in the presence of heat.14 Avoid whenever possible.
This catch-all category for uncommon plastics. The most common of these uncommon plastics used for food storage is polycarbonate (PC). The material is frequently employed to manufacture durable (reusable) water bottles, and BPA is used as a constituent chemical in many PC products. PC leaching is even more pronounced in the presence of heat. However, some PC products are made without BPA. Unless #7 plastic can be sourced and/or tested for its chemical content, it should be viewed with suspicion regarding leaching of hazardous substances.
Bioplastics – Deriving plastic from plant-based sources instead of petrochemicals has become more common over the past two decades. While food packaging made from bioplastics is generally more biodegradable in commercial composting operations than conventional containers, bioplastics still might contain toxic additives.15 If product suppliers do not disclose this information, do not assume bioplastics are immune to concerns about chemical leaching.
Black Plastic – In 2018, a study conducted in the U.K. found that products manufactured with “black plastic” were frequently made with resin sourced from recycled electronics.16 This resin is frequently contaminated with bromine fire retardants, heavy metals, and may also contain phthalates. And sometimes this feedstock is used in products exposed to food, including single-use coffee cups, coffee-cup lids, eating utensils, and food trays. Unless black plastic can be sourced and/or tested for its chemical content, it should be viewed with suspicion regarding leaching of hazardous substances.
If you do use plastic storage containers, consider ways to use them more safely. They are more likely to leach toxic additives:
• when they are heated (including by hot stored food and in hot cars);
• when exposed to sunlight;
• when they store acidic foods (such as tomato sauce) or fatty foods (such as meat and cheese);
• if they have abrasions and scratches from repeated use;
• if cleaned in dishwashers.
Also, keep in mind that older containers are more likely to leach than newer ones.
Fluoropolymers – Though they are not used everywhere, chemicals similar to Teflon™ are frequently applied to food packaging because they make the food less likely to stick or make food grease less likely to spill. Unlike Teflon™, which some of its defenders claim is an inert substance, these chemicals have been proven to leach into food.17 Food-package applications that might use fluoropolymers include fast-food wrappers, French-fry boxes, single-use plates, bakery bags, microwave popcorn packages, and pizza boxes. Consuming junk food has its own inherent risks; they can only increase with exposure to these chemicals.
Health effects associated with exposure to this class of chemicals include learning and developmental problems in children, low-sperm counts in men and fertility problems in women, high cholesterol, increased liver enzymes, decreased vaccination response, thyroid disorders, pregnancy-induced hypertension and preeclampsia, and testicular and kidney cancer.18
Inert Mineral-Based – Cookware made with inert minerals include non-coated glass (such as Pyrex), glass-ceramic (such as Corningware, and total ceramics (such as Xtrema and Emil Henry). They can withstand high amounts of heat without leaching toxic chemicals or metals into food or liquids being heated.
They are not as resilient to fast temperature changes as other materials. Cracks can sometimes occur due to abrupt temperature changes (e.g., from oven temperatures to cold wash water). And they are breakable if dropped.
Also keep in mind that products made of borosilicate can tolerate sudden temperature changes better than those made with soda lime silicate.19 Because of this, they are much less likely to shatter under this kind of stress.
Older ceramic cookware (including antiques), as well as some imported products, may have lead, cadmium, and other toxic heavy metals in the glazes and pigments. It would be prudent to test them before use.
Titanium – Titanium is one of the strongest metals ever manufactured, and one of the least impactful on human health. It does not leach or provoke allergic reactions in people. There are 3 types of cookware made with it.
Camping cookware uses this metal in pure form because it is light weight, though these implements do not heat evenly and are not appropriate for common kitchen use. Some cookware has its cooking surface lined with scratch-resistant titanium, while the underlying metals of stainless steel and/or aluminum allow even heat distribution. And there are other hybrid products with steel or aluminum bases below a titanium-ceramic cooking surface.
Cast Iron – Unlike mineral-based materials that can break if dropped, it is more likely that cast-iron cookware will break whatever it falls on. It can literally last a lifetime if properly cared for. This class of materials needs to be seasoned by heating oil in it, which seals the pores and makes the cookware much easier to clean.
It can leach iron into food, particularly if the food being cooked is acidic. Iron in acidic foods like tomato sauce can also carry an unflavorful metallic taste. Leached iron might be a health problem to people sensitive to the mineral, but it is not a danger to most of the general public.
Carbon steel – Carbon steel has the same benefit of durability as cast iron, but is much lighter, less brittle, and heats more evenly. It still must be seasoned though, will still leach iron, and is still not optimal for cooking acidic foods.
Stainless Steel – As discussed in the container section, this is a relatively benign material, but it can leach nickel and chromium, particularly with prolonged cooking or acidic food. About 10% of the public is allergic to nickel, with dermatitis being the most common reaction. To avoid nickel in stainless containers, cookware and eating utensils, look for the rating that notes the percentage of metals in the product.
Silicone – Silicone rubber is used to make molded cookware, or to coat metal cookware. It is valued for its non-stick qualities. Most studies show it either does not leach chemicals into food, or that such leaching is not significant or dangerous.
Products with silicone coatings on metal do wear over time. Consumers should also note that some molded products contain cheap fillers in the rubber, which have been known to smell when heated. This is indicated by a white gel-like substance that appears when the products are squeezed. So purchasers of silicone cookware should look for higher-quality products.
Porcelain Enamel – This generic type of cookware uses baked enamel over a metal substrate of cast iron, aluminum, or stainless steel. The enamel on the inside of most products is inert and safe. While some products are incredibly durable, harm can occur if the enamel wears away or is chipped. Food can be exposed to the metal (particularly worrisome for an aluminum substrate), and the chips are not something people want to swallow. Consumers may want to discard the products at that point.
Copper – Older copper cookware (such as antiques) can leach unacceptable amounts of copper into food and should be avoided. Most copper cookware sold in the U.S. today is a hybrid with a copper base and a stainless steel, ceramic, or tin cooking surface, and is safer.
However, that assumes the surface is not scratched to allow food to come in contact with the base. Once steel or ceramic linings are damaged, they cannot be restored and the vessel cannot be used safely. While gourmets love copper cookware with tin coatings because of its precise flow of heat, the additional time and money for retinning will usually be spent only by dedicated chefs and foodies.
Aluminum – Though aluminum is benign in small quantities, it can be neurotoxic in larger doses. This concern is one reason that much of the aluminum cookware in the U.S. is now anodized. While this may reduce its leaching into food, there is evidence that it will not eliminate it.20 And if the anodized coating is scratched because of cleaning or wear, leaching will become more pronounced.
BPA – It is common for certain cookware and appliances such as coffee makers and blenders to be partially made with clear polycarbonate, which often has BPA in the resin. There are alternative products on the market that boast being “BPA-free.” However, unless the manufacturers are stating what the alternative resin is made of, it is better to find alternatives made of glass, ceramic, or stainless steel.
Fluoropolymer Coatings – Polytetrafluorethylene (PTFE) is more commonly known by one of its trade names Teflon™, and is added to cookware as a non-stick coating. Its manufacturers and proponents try to portray the material as inert and not dangerous if used properly and not overheated. However, things do not always go right in a kitchen. (In 2019, 49% of house fires in the U.S. were related to cooking.)21
Overheating an empty pan coated with PTFE above its recommended level for safety can take place in 2 to 5 minutes, causing the coating to smoke and emit toxins.22 The smoke has been known to kill pet birds and cats, while being strong enough to give people flu-like symptoms. 23 The long-term health effects for people contracting “Teflon Flu” are unknown.
PTFE coatings on cookware will also eventually wear off. Some of this goes into washwater, but it is inevitable that some of the coating molecules are ingested. The accumulation of fluorocarbons in food has not been widely studied. Avoiding this type of cookware is, at the least, a precautionary measure. And once the material does flake off, the underlying surface is usually aluminum, with its own inherent toxicity from leaching.
Consumers should beware that in the past, fluorocarbon PTFE coatings were made with the chemical PFOA. The base chemical has now changed, but it is not clear that the replacement is better than the old ones. So if you see a pan labeled non-stick but “PFOA Free,” it is quite possible it is using a replacement fluorocarbon and not a safer technology.
Other reasons to avoid this cookware are its upstream production and downstream disposal concerns. Production of fluoropolymers is extremely toxic, with documented contamination to neighbors and the environment surrounding manufacturing sites. Cleaning treated cookware, accidental fires, and ultimate disposal of worn cookware create further pathways for PTFE to be released into the environment.
Non-Stick Ceramics Without Fluoropolymers – This class of cookware uses a ceramic surface over a metal base of aluminum or steel (or a hybrid of the two). A non-stick coating made without fluorocarbons is applied to the surface.
While some consider this cookware a safe alternative to Teflon®, many of these products use coatings made with nanotechnology. These coatings are relatively new and unstudied, and may pose harm to consumers. For instance, a 2016 study showed that rats consuming food-grade titanium dioxide nanoparticles developed immune disruption and precancerous lesions in their colons.24
Consumers looking for safe cookware might want to exercise the precautionary principle and wait until the safety of these products is more proven.
Courtesy Pixabay/ Alexas_Fotos
1 Historical facts about lead poisoning from Lessler, Milton, “Lead and Lead Poisoning from Antiquity to Modern Times,” Ohio Journal of Science, 1988, pp. 78-84.
2 Beagrie, Neil, “The Romano-British Pewter Industry,” Britannia, Vol. 20 (1989), p. 169.
3 Sein, Min, “Lead Poisoning from Cooking Utensils,” The Indian Medical Gazette, October 1937, pp. 595-598.
4 Pearson, David, “Packaging,” The 20 Ps of Marketing, Philadelphia, PA: Kogan Page Limited, 2014, p. 69.
5 Bolger, P. Michael, Clark D. Carrington, Stephen G. Capar & Michael A. Adams, Reductions in Dietary Lead Exposure in the United States, Chemical Speciation & Bioavailability, V. 3, Issues 3-4, 1991, pp. 31-36.
6 Lead-Soldered Food Cans, Final Rule, Washington, DC: Department of Human Services, Food and Drug Administration, 21 CFR Part 189 [Docket Nos. 82P-0371 and 91N-0165], June 27, 1995.
7 op. cit., Lessler, Milton. P. 80.
8 “Lead Toxicity, What Are Possible Health Effects from Lead Exposure?” Atlanta, GA: Centers for Disease Control, Agency for Toxic Substances and Disease Registry. June 12, 2017.
Lanphear, Bruce, et al., “Low-level lead exposure and mortality in US adults: a population-based cohort study,” The Lancet, March 12, 2018.
9 Kamerud, Kristin, et al., “Stainless Steel Leaches Nickel and Chromium into Foods During Cooking,” Journal of Agriculture and Food Chemistry, V. 61, Issue 39, October 2, 2013, pp. 9495-9501.
10 Engel, Connie, at al., Buyer Beware, San Francisco, CA: Breast Cancer Fund, April 2016.
11 Bassioni, Ghada, “Why You Shouldn’t Wrap Your Food in Aluminium Foil Before Cooking It,” The Huffington Post, December 6, 2017.
12 Schwartz, Larry, “Toxic Traps: When These 7 Types of Plastic Are Dangerous,” Alternet, March 22, 2016.
Keresztes, Szilvia, “Leaching of antimony from polyethylele terephthalte (PET) bottles into mineral water,” Science of the Total Environment, 2009, pp. 4731-4735.
13 Karlsson, Frida, Estrogenic Substances in Plastic Bottles, Örebro, Sweden: Örebro University, Biology, January 10, 2014.
14 Ahmad, Maqbool and Ahmad S. Bajahlan, “Leaching of styrene and other aromatic compounds in drinking water from PS bottles,” Journal of Environmental Sciences, V. 19, 2007, pp. 421-426.
15 Zimmermann. Lisa, et al., “Benchmarking the in Vitro Toxicity and Chemical Composition of Plastic Consumer Products,” Environmental Science & Technology, V. 53, August 5, 2019, pp. 11467−11477. 16 Turner, A, “Black plastics: Linear and circular economies, hazardous additives and marine pollution.” Environment International, V. 117, August 1, 2018, pp. 308-318.
17 Schaider, Laurel, et al., “Fluorinated Compounds in U.S. Fast Food Packaging,” Environmental Science and Technology Letters, V. 4, February 1, 2017, p. 105.
18 Ibid., p. 106.
19 Bradt, R.C. and R.L. Martens, “Shattering glass cookware,” American Ceramic Society Bulletin, V. 91, No. 7, September 2012, pp. 33-38.
20 Leaching tests for unidentified aluminum teaware, cookware, and bakeware by Brandywine Science Center, Kennett Square, PA, August 17, 2009.
(Disclosure: While these tests were ostensibly objective, they were funded by Xtrema, a competitor that manufactures ceramic cooking vessels.)
21 Ahrens, Marty, Home Structure Fires, Quincy, MA: National Fire Protection Association, October 2019, pp. 4-5.
22 “Canaries in the Kitchen, Teflon Toxicosis,” Washington, DC: Environmental Working Group, May 15, 2003.
24 Golja, Viviana, et al., “Characterisation of food contact non-stick coatings containing TiO2 nanoparticles and study of their possible release into food,” Food Additives & Contaminants, V. 34, No. 3, January 31, 2017, pp. 421-433.
AVOIDING LEAD IN CERAMICS AND GLASS
1. Buy no-lead and low-lead products. Even if you buy new products made to U.S. safety standards, if they have high amounts of lead, they can still eventually leach more than the standards allow due to chips, silverware scratches, and wear. Sourcing the right products at the beginning is your best option. The term low-lead generally means 90 to 100 parts per million or less. Even if chipped, scratched, or worn, there is not much lead there to harm people.
2. Lead testing offers clues. But it is not always cost effective.
Lead test kits purchased in hardware stores are sometimes helpful. However, they only offer clues and are not definitive. They will measure positive at no lower than 600 parts per million, and will not measure the amount of lead actually embedded in the product.
There are expensive X-ray fluorescence (XRF) analyzers that measure the lead and other metals embedded in a product, but these devices cannot ultimately tell how much of the embedded metal has leached or will leach in the future.
There are also laboratories that can actually measure the lead that has leached into a vinegar solution that has been sitting on or in products for several hours. However, testing numerous dishes numerous times over the years can be costly and time consuming.
3. Avoid products that are generically suspect. Though every single product is different, there is a greater probability of finding lead in the following items:
• Traditional glazed terra cotta made in some Latin American countries (such as Mexican bean pots) unless labeled lead-free;
• Highly decorated traditional dishes used in some Asian communities;
• Home-made or hand-crafted tableware, unless the maker uses a lead-free glaze;
• Bright colors or decorations on the dish surfaces that touch the food or drink. This includes the upper rim of a cup or bowl;
• Decorations on top of the glaze instead of beneath it;
• Legacy tableware purchased before the late 1980s, or antiques (second-hand stores are china roulette);
• Products with corroded glaze (that might release lead), or a dusty or chalky grey residue on the glaze after washing the product (which may indicate released lead).
4. Limit kitchen practices that increase risk.
• Do not heat food on stoves or in microwaves in dishes that might contain lead. Heat speeds up the leaching process.
• Do not store foods in dishes that might contain lead. Time enhances the leaching process.
• Do not eat food in dishes that might contain lead with highly acidic foods or drinks. Acid enhances the leaching process.
• Do not wash dishes that might contain lead in a dishwasher. This can degrade the glazing and make leaching more likely.
Environmental Food Rating Information
BPA Packaging Database
Proposition 65 BPA
Under the “Proposition 65” law in the state of California, food product companies are required to list products that have BPA in their food containers. This Web site has a downloadable list for consumers who want to avoid them. In some cases, the list also states when the company intends to switch to BPA-free containers.