Canned food is one of the most convenient pantry staples in the modern kitchen. It's also one of the most underappreciated sources of daily plastic chemical exposure in your diet. The issue isn't the metal itself — it's what's coating the inside.
Nearly every commercially produced steel or aluminum food can uses an interior coating to prevent corrosion and metallic flavor. For decades, that coating was almost universally an epoxy resin containing bisphenol A (BPA). When researchers began documenting that BPA mimics estrogen and disrupts hormonal signaling, manufacturers responded — but mostly by substituting structurally similar bisphenol compounds (BPS, BPF) that appear to carry the same concerns.
The result: switching from BPA-lined to "BPA-free" cans often means trading one problematic plastic chemical for another. Truly safer pantry alternatives require stepping out of the can format entirely — and the good news is that the options are now plentiful and comparably priced.
What Is the Can Lining, and Why Does It Matter?
Steel and aluminum corrode when exposed to acidic foods. Without an interior coating, your tomato sauce would react with the metal, creating off-flavors and oxidation. The solution the food industry settled on — starting in the 1950s — was to spray a thin epoxy resin layer on the interior of every can. This resin is what your food actually contacts.
Epoxy resins have traditionally been synthesized from BPA. Even if no free BPA remains in the cured resin, the chemical is released again over time through a process called hydrolysis — breakdown caused by moisture, acidity, and heat. The longer a can sits on a shelf, the more the lining degrades. The more acidic the food, the faster it leaches. The higher the temperature (including during cooking, canning, or reheating), the more dramatically the rate increases.
"Heating canned food increases BPA migration by 55% compared to room-temperature storage — yet most people don't think twice about heating soup in a can on the stove."
When manufacturers pivoted to "BPA-free" formulations after public pressure, most used bisphenol S (BPS) or bisphenol F (BPF) — structurally near-identical molecules that bind to estrogen receptors in similar ways. A 2015 study in Environmental Health Perspectives found BPS to be as potent as BPA in disrupting estrogen receptor signaling in cell cultures. The replacement chemicals are less studied, not safer.
Which Canned Foods Carry the Highest Risk?
Not all canned goods carry equal risk. The two primary drivers are acidity (how aggressive the food is in dissolving the lining) and contact time (how long the food has been sitting in the can).
Canned tomatoes and tomato products (whole, crushed, paste, sauce) carry the highest BPA leaching rates of any canned product category. Tomatoes have a pH of 3.5–4.5 and spend weeks to years in the can. Studies consistently find canned tomato products among the top BPA sources in the diet. Canned citrus and high-acid fruits rank similarly. Canned beans have moderate acidity but extremely long shelf and contact times. Canned soups combine high contact time with frequent reheating.
Lower-risk canned products include whole fish packed in water (sardines, salmon, tuna) — particularly from brands that certify BPA-free lining — and dry-packaged items like coconut milk in carton or certified BPA-free can format. However, "lower risk" compared to canned tomatoes still means measurable exposure. The only way to eliminate the risk is to eliminate the can.
Glass Jar Alternatives: The Best Swap
Glass is chemically inert. It does not leach, it doesn't react with acidic foods, and it requires no interior coating. Products packed in glass are the cleanest pantry option available — and increasingly available at prices comparable to premium canned brands.
Stop Canned tomatoes (regular or BPA-free)
Switch Glass-packed tomatoes
- Packaging: Glass jar with metal lid
- Plastic contact: None (glass body)
- Certification: USDA Organic
- Cost vs. canned: +$0.50–$1.00 per unit
- Packaging: Glass bottle, metal screw cap
- Plastic contact: None
- Country of origin: Italy
- Best use: Pasta sauce, pizza sauce, soup base
Carton Alternatives: Tetra Pak for Broths and Soups
Tetra Pak (aseptic cartons) use a layered construction: paperboard, thin aluminum, and a minimal polyethylene inner layer. The plastic contact surface is significantly thinner and less reactive than can epoxy lining, and there is no BPA or bisphenol compound used. Carton-packed broths and soups are a meaningful upgrade from canned equivalents.
Stop Canned broths and soups
Switch Carton-packed broths and soups
- Packaging: Tetra Pak aseptic carton
- BPA: None
- Certification: USDA Organic
- Cost vs. canned broth: Comparable (~$0.12/oz)
- Packaging: Tetra Pak carton
- BPA: None
- Cost vs. canned tomatoes: Comparable to similar (~$2.50–$3.50)
- Best use: Soups, stews, sauces
The One Canned Brand That Did It Right: Eden Organics
Eden Organics is the only major canned goods brand in the US to use an oleoresin interior lining — a plant-derived coating that contains no bisphenol compounds. They have used this lining on their bean products since 1999. Their tomato products are packed in amber glass jars.
- Lining: Oleoresin (plant-based, no BPA/BPS/BPF)
- Certification: USDA Organic
- Verification: Third-party tested, no bisphenol compounds
- Cost vs. standard organic canned: +$0.50–$0.75/can
- Cost vs. dried beans (cooked from scratch): ~4x higher — dried beans are still the gold standard
FAQ: But aren't BPA-free beans expensive? At ~$2.49/can vs. ~$1.99 for standard organic canned beans, the premium is about $0.50 per can. A family eating beans 3x per week pays roughly $6–$8/month more to eliminate bisphenol exposure from this source. Alternatively, dried beans cooked from scratch cost approximately $0.50 per serving (vs. $0.99–$1.25 for canned) and carry zero plastic exposure.
The Cost-Benefit Case
The most common objection to switching from canned food is cost. Here's the honest math:
- Glass-packed tomatoes vs. canned: +$0.50–$1.00 per use. A household using 2 cans of tomatoes per week spends ~$52–$104 more per year.
- Carton broth vs. canned: Roughly price-equivalent at most retailers. This is a free swap.
- Eden Organics beans vs. standard canned: +$0.50/can. At 3 cans/week, about $78 more per year.
- Dried beans vs. any canned: Saves money AND eliminates exposure. About 20 minutes of hands-on time per batch. A pressure cooker (Instant Pot) reduces cook time to 25 minutes total.
The real cost-benefit question is: what's the cost of chronic low-level hormone disruption compounded over years? BPA and its replacements are associated with increased cancer risk, metabolic disruption, and reproductive effects in the research literature. The dietary swap is among the most accessible and affordable in this category.
Complete Swap Guide: Pantry by Category
Switch Bionaturae glass jars · Mutti glass bottles · Pomi Tetra Pak cartons
Switch Eden Organics cans (oleoresin) · Dried beans cooked from scratch · Tetra Pak-packaged options where available
Switch Pacific Foods cartons · Imagine cartons · Homemade broth stored in glass mason jars (freezes well)
Want the Complete Pantry and Kitchen Guide?
The Complete Plasticproof Guide covers every kitchen swap — cookware, food storage, water filters, and your full pantry — with the research and ranked product recommendations in one place.
Frequently Asked Questions
Yes — most canned foods still use epoxy resin can linings that contain BPA (bisphenol A) or its replacements BPS or BPF. A 2016 study found BPA in 67% of canned food samples tested. Acidic foods like tomatoes, fruits, and beans leach significantly more plastic compounds than neutral foods. Heating canned food dramatically increases leaching rates. The safest option remains glass jar alternatives where available.
Acidic foods leach the most: canned tomatoes and tomato products are consistently the highest BPA source in canned food. Canned citrus, fruit in syrup, beans (due to long contact time), and soups are also high-risk. Lowest risk: whole fish in water packed in BPA-free certified cans.
Not necessarily. Most "BPA-free" cans use BPS or BPF — chemically similar bisphenols that show similar endocrine-disrupting effects in preliminary research. "BPA-free" means one plastic compound was removed and another substituted, not that the product is plastic-chemical-free. Truly safer alternatives are glass, cartons, or Eden Organics' oleoresin-lined cans (the only major brand using a non-bisphenol alternative).
Best alternatives in order: (1) Glass jar packaging — Bionaturae, Mutti, and Jovial for tomatoes. (2) Tetra Pak cartons — Pacific Foods and Pomi for broths, soups, and tomatoes. (3) Frozen vegetables — nutritionally equivalent, no plastic lining. (4) Dried legumes — cheapest per serving and zero plastic exposure. For fish, Wild Planet and Safe Catch offer certified BPA-free cans.
Yes, significantly. A 2018 study found heating canned food increased BPA migration by 55%. Never microwave food in a can and avoid simmering directly in the opened can on the stove. Transfer to a stainless steel or glass pot immediately after opening. Also: never store leftover food in the open can in the fridge — transfer to glass containers.
Canned infant formula in liquid form was historically among the highest BPA sources for babies. FDA restricted BPA in infant formula packaging in 2013, but replacement chemicals (BPS, BPF) have not been fully evaluated for infant safety. The safest options are powdered formula in cardboard packaging, or glass jar baby food for solids. Avoid plastic squeeze pouches for any warm food — they carry their own microplastic concerns.
A 2011 Stanford study found that switching to glass and carton packaging reduced urinary BPA levels by 66% within 72 hours. Free BPA has a relatively short half-life (~6 hours) in the body — the problem is continuous re-exposure from daily food choices. Switching your highest-exposure items (canned tomatoes, canned soups, canned beans) to glass or carton alternatives makes an immediate measurable difference.
Sources
- Breast Cancer Prevention Partners. "Buyer Beware: Toxic BPA and Regrettable Substitutes in the Linings of Canned Food." 2016.
- Ramsey JM, et al. "Thermal and acidic degradation of bisphenol A-based epoxy coatings." Food & Chemical Toxicology, 2014.
- Rochester JR, Bolden AL. "Bisphenol S and F: A Systematic Review and Comparison of the Hormonal Activity of Bisphenol A Substitutes." Environmental Health Perspectives, 2015.
- Yan Z, et al. "Effect of Cooking on BPA Migration from Can Linings." Environmental Research, 2018.
- Rudel RA, et al. "Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention." Environmental Health Perspectives, 2011.
- Carwile JL, et al. "Canned Soup Consumption and Urinary Bisphenol A: A Randomized Crossover Trial." JAMA, 2011.
- Simoneau C, et al. "Determination of bisphenol A migration into canned foods." Food Additives & Contaminants, 2012.
- Calafat AM, et al. "Urinary Concentrations of Bisphenol A and 4-Nonylphenol in a Human Reference Population." Environmental Health Perspectives, 2005.
Protect Your Whole Kitchen
Canned food is just one exposure source. The Complete Plasticproof Guide covers your cookware, cutting boards, water supply, and every food storage decision — ranked by actual impact.
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