Home cooks are always looking for more convenience in the kitchen—from faster cooking methods to easier clean-up, and of course, relying on prepared food. There are still many questions, and even disagreements, about the safety of these conveniences, however. Concerns about radiation-emitting equipment, nonstick linings on pots and pans and ubiquitous plastics are driving many to seek cookware made from more traditional materials. What are the safest pieces of cookware to use, and what care do they require to keep them safe?
How has home cookware changed over time?
Home cooking equipment has changed drastically from the earliest earthenware pottery our ancestors used thousands of years ago. While cast iron was first used in China in the 5th century BC, it was not until the 18th century and the rise of industrialized manufacturing that its use became widespread in cooking in America and Europe. Metals, such as copper, became useful for their excellent heat conduction and malleability into pots of different shapes. Metals were used to make pots, pans and Dutch ovens that hold large volumes. Cooking was done over the high heat generated by open flames until the 19th century. Gas ovens and electric ranges simplified the process of cooking and reduced the space needed in the home kitchen.
While we still regularly use cookware made from cast iron, copper and steel, new tools—such as Instant Pots, silicone baking sheets and air fryers—are now commonplace for home cooks. However, many of these modern tools and pieces of equipment are made of materials that contain chemicals of concern to human health.
What cookware materials are safest to use in the kitchen?
Cast iron and stainless steel are generally very durable and safe to use both on the stovetop or in the oven (unless they have a handle made of plastic or wood). Glass and ceramic are well-suited for use in the oven or microwave. Stone can also be used in the oven.
Silicone is increasingly being used in kitchens to provide a nonstick surface useful for lining baking sheets and comprising muffin cups, spatulas and even dishwasher-safe reusable bags. Silicone is chemically inert and nonreactive, meaning you don’t have to be concerned about reactions with acidic or hot foods. Metal utensils are fine to use with glass and ceramic cookware, and utensils made of softer materials—such as wood, bamboo and silicone—are safe to use on all cooking surfaces.
What materials are of potential concern for home cooks?
Nonstick pans are popular for their easy cleaning and reduced need for cooking oil. Polytetrafluoroethylene (PTFE), commonly known as Teflon, was used for nonstick coatings since the mid-1900s, and it was admired for its stability and ability to create a frictionless surface. However, one of the molecules formerly used to make Teflon, perfluorooctanoic acid (PFOA), has been associated with certain types of cancer, infertility and cardiovascular disease. We now know that toxins (such as PFOA) are released when these nonstick pans are used for cooking above 500°F as well as when the coating starts to scratch or peel. Cookware with these coatings are not typically very durable, and the nonstick coating may wear off quickly. They may only last about five years before needing to be replaced, meaning they will, unfortunately, likely end up in landfills. While PFOA has not been used in Teflon since 2013, scientists have expressed similar concerns about the thousands of other perfluoroalkyl substances (PFAS) used in various types of nonstick cookware and other consumer goods.
Some modern pieces of equipment such as Instant Pots and air fryers are also commonly coated with nonstick surfaces. While consumers appreciate their efficiency and flexibility, little information about their safety is available. Even if the nonstick coatings are made without PFAS, they may be made of hard-anodized aluminum coated with a nonstick layer of ceramic; if scratched, this can expose food to the aluminum layer. Opting for a stainless steel coating on these newer cookware items is likely the safest option (but again, it’s important to take care not to scratch them with metal utensils). Further, their exteriors often require the use of petroleum-based plastic, and many of them can be difficult to clean. They also take up precious real estate in cabinets or on countertops.
While it is a durable material, copper can leach into acidic foods when cooking,
potentially causing copper poisoning. It also can’t be put in the dishwasher. If using copper pots and pans, look for copper lined with stainless steel to minimize exposure to potentially toxic levels of this metal.
Aluminum is also widely used in food packaging as well as cooking because it is great at conducting heat, inexpensive and lightweight. However, it is also very reactive with acid and dissolves most easily when pots and pans are worn or pitted. Longer cooking and storage times also lead to more leaching into food. If using aluminum for tools such as baking sheets or grill pans, choose pieces that are anodized, or hardened through a process to reduce reactivity, or clad in a non-reactive material, such as stainless steel. American adults consume an average of 7–9 mg of aluminum per day through dietary exposure (in addition to our exposure through medications, personal care products, air, etc.). The European Food Safety Authority has determined that a weekly aluminum intake of 1 mg per kilogram of body weight is tolerable. Since we are already consuming roughly that amount, it is best to choose cookware made from safer materials to prevent toxicity.
Is it safe to use plastics in the kitchen?
Though it is common to see adults in workplaces and homes microwaving their food in plastic containers or covered in plastic lids or films, these practices should be avoided. They should not be used to heat food or beverages (or even to line or cover the containers used to heat them). Avoid plastic liners for slow cookers, which are otherwise typically made of ceramic and safe to use. Plastics leach endocrine-disrupting chemicals such as BPA (and its successor BPS) and phthalates into our food to the point that microplastics have been found in some freshly harvested fruits and vegetables, according to a recent study by Conti et al. Refer to our previous article about pervasive plastics in the food supply for tips on reducing your exposure to these harmful compounds.
What are the optimal ways to care for your cookware?
It’s important to use safe, non-abrasive brushes and detergents to prevent damage to cookware.
Washing by hand
Combine baking soda and peroxide to remove debris and grease from most surfaces, other than cast iron.
For nonstick surfaces, use a gentle mix of baking soda and water; let it sit in the pot/pan for at least several minutes to best loosen food debris.
Use cooking oil and coarse salt to remove burnt-on food debris from steel or cast iron pans without removing the pan’s sought-after seasoning.
Don’t wash cast iron pans after normal use; instead, wipe with a cloth or paper towel.
View this America’s Test Kitchen website for more tips about caring for cast iron.
Using the dishwasher
Many (but not all) noncoated pots and pans can go in the dishwasher, but avoid using it for plastics, sharp knives, copper and cast iron.
For ceramics with delicate paint, wash on the top rack.
Choose store-bought dishwasher detergent that is gentle for your cookware and safe for your skin.
Avoid fragrances and dyes, polyacrylates, methylisothiazolinone, benzisothiazolinone and sodium hypochlorite (and see the Environmental Working Group’s website for more information).
Remember to let your cookware fully cool and dry before storing.
How can I use the safest cookware and methods in my home kitchen?
Refer to trusted resources such as the Clemson Cooperative Extension Home and Garden Information Center, NutritionFacts.org and the American Cancer Society for more information about safe cookware and cooking methods.
When possible, choose pots and pans made of stainless steel, lined copper or cast iron and baking dishes made of glass, stone or ceramic.
The ability to hold and distribute heat varies among these materials, so select the material best suited for your purpose. Visit this Kitchen Kapers website to learn more about which material is best for each cooking method.
If using nonstick pots and pans, minimize heat and abrasion by cooking on low heat, hand washing with mild detergent and a non-abrasive scrubber, using wooden or silicone utensils and cookware made to US safety standards and ceasing use of these pans when they show signs of wear, such as discoloration and scratches. If possible, avoid throwing them away by looking for scrap metal yards or company take-back programs.
Resources
Agency for Toxic Substances and Disease Registry. “Public Health Statement for Aluminum.” CAS#: 7429-90-5. 2008. www.atsdr.cdc.gov/phs/phs.asp?id=1076&tid=34
Barry V et al. Perfluorooctanoic acid (PFOA) exposures and incident cancers among adults living near a chemical plant. Environ Health Perspect. 2013;121(11-12):1313-8. ehp.niehs.nih.gov/doi/10.1289/ehp.1306615
Fei C et al. Maternal levels of perfluorinated chemicals and subfecundity. Hum Reprod. 2009;24(5):1200-5. academic.oup.com/humrep/article/24/5/1200/711357
Klotz K et al. The Health Effects of Aluminum Exposure. Dtsch Arztebl Int. 2017;114(39):653-659. www.aerzteblatt.de/int/archive/article/193516
Lin PD et al. Per- and polyfluoroalkyl substances and blood lipid levels in pre-diabetic adults-longitudinal analysis of the diabetes prevention program outcomes study. Environ Int. 2019;129:343-353. www.sciencedirect.com/science/article/pii/S0160412019305094?via%3Dihub
Oliveri Conti G et al. Micro- and nano-plastics in edible fruit and vegetables. The first diet risks assessment for the general population. Environ Res. 2020; 187:109677. www.sciencedirect.com/science/article/pii/S0013935120305703?via%3Dihub
Williams K. The history of American-made heirloom cast iron skillets. Southern Kitchen. 2018. www.southernkitchen.com/articles/entertain/the-history-of-american-made-heirloom-cast-iron-skillets. Accessed October 31, 2020.
Wolke RL. Silicone in the Kitchen. The Washington Post. 2004. www.washingtonpost.com/archive/lifestyle/food/2004/01/21/silicone-in-the-kitchen/3f2d3717-10fe-470f-8815-0e8ff308b10b/. Accessed October 31, 2020.
Christina Badaracco, MPH, RD
Christina is a registered dietitian and author who aims to improve access to healthy and sustainable food and educate Americans about the connections between food and health. She loves to experiment with healthy recipes in the kitchen and share her creations to inspire others to cook.
Christina completed her dietetic internship at Massachusetts General Hospital and earned her Master of Public Health degree from the University of California, Berkeley. Previously, she graduated with a degree in Ecology and Evolutionary Biology from Princeton University, after conducting her thesis on sustainable agriculture and energy in Kenya. She has done clinical nutrition research at the National Institutes of Health, menu planning and nutrition education at the Oakland Unified School District and communications at the Environmental Protection Agency’s Office of Water. She has also enjoyed contributing to children’s gardens, farmers’ markets and a number of organic farms.
Comments