Microplastics in Canned Tuna and Salmon: Double Exposure
Quick Answer
Canned tuna and salmon are uniquely problematic: they combine fish-borne microplastics with epoxy/BPA can liner leaching over the full shelf life. Multiple studies have found microplastics in 100% of canned seafood samples tested, with bluefin tuna concentrating the most due to bioaccumulation up the food chain. Pouch tuna isn't safer — the plastic-foil laminate adds polyethylene migration. Cleanest options: glass-jarred wild salmon (Wild Planet glass, Vital Choice glass) or fresh wild-caught fish from a local fishmonger. Choose smaller fish (sardines, anchovies, mackerel) over large predators when canned is unavoidable.
Key Takeaways
- Canned seafood combines fish-borne microplastics (gut, gills, muscle) with epoxy can-liner BPA/BPS leaching.
- Larger predator fish (bluefin tuna, swordfish, mackerel) bioaccumulate microplastics + mercury — limit to once/month max.
- Smaller fish (sardines, anchovies, small albacore, light skipjack tuna) have lower bioaccumulation.
- BPA-free can liners still typically use BPS or BPF — “BPA-free” ≠ safe.
- Cleanest: glass-jarred wild salmon (Wild Planet, Vital Choice), fresh fish from a fishmonger.
- Pouch tuna isn't safer — adds PE polyfilm microplastic on top of fish content.
Why canned fish is a double-exposure scenario
Most canned-food microplastic discussions focus on the can liner. For canned fish specifically, you get two compounding sources:
- Fish-borne microplastic. Sea fish ingest plastic from ocean water. Particles concentrate in gut, gills, and to a lesser degree muscle tissue. Canning typically uses whole-fillet pieces (tuna, salmon) or whole small fish (sardines, anchovies).
- Can liner migration. Steel cans are coated inside with a thin epoxy resin (typically BPA-derived or BPA-replacement like BPS/BPF) to prevent corrosion. Over the 2-3 year shelf life, plasticisers migrate into the food — accelerated by the oil/water and any acidity.
- Bonus issue: heat sterilisation. The retort sterilisation process (heating sealed cans to ~120°C) accelerates initial migration of can-liner chemicals into the fish.
Bioaccumulation: smaller fish are cleaner
Microplastics and mercury both concentrate up the food chain. Small fish eat plankton (some microplastic); medium fish eat small fish (more); large predators eat medium fish (most). This is why sardines, anchovies, mackerel (smaller varieties), and small light skipjack tuna have lower contamination than bluefin tuna, swordfish, and yellowfin.
| Fish | Bioaccumulation | Safe frequency (general adult) |
|---|---|---|
| Wild Alaskan salmon (canned) | Low-moderate | 2-3x per week OK |
| Sardines (canned) | Low | 2-3x per week OK |
| Anchovies (canned/jarred) | Low | 2-3x per week OK |
| Light skipjack tuna (canned) | Moderate | 1-2x per week max |
| Albacore "white" tuna (canned) | Higher mercury + microplastic | 1x per week max |
| Yellowfin tuna (canned/fresh) | High mercury + microplastic | 1-2x per month |
| Bluefin tuna (sushi/raw) | Highest bioaccumulation | Rarely; avoid for pregnancy |
| Swordfish, king mackerel, shark | Highest mercury | Avoid for pregnancy and children |
Brands and packaging ranked
| Brand / Product | Packaging | Relative exposure |
|---|---|---|
| Wild Planet Wild Sockeye Salmon (glass jar) | Glass jar with metal lid | Lowest — no can liner |
| Vital Choice Wild Salmon (glass jar) | Glass jar | Lowest |
| Mary's Gone Crackers / Pacific Naturals brands in glass | Glass | Lowest |
| Wild Planet Skipjack Tuna (BPA-free can) | BPA-free steel can (uses BPS/BPF liner) | Moderate — better than BPA but still polymer liner |
| Safe Catch (Mercury Tested) Tuna | BPA-free can | Moderate — verified low mercury, similar can liner |
| StarKist Tuna | Standard can with BPA-NI liner (newer products) | Moderate |
| Bumble Bee, Chicken of the Sea | Standard steel can | Moderate |
| Tuna in foil pouches (StarKist Premium Pouches, etc.) | PE-laminated foil pouch | Higher — adds polyethylene migration |
| Restaurant raw tuna sushi (especially bluefin) | Often black plastic tray for takeout | Highest (mercury + raw + tray) |
Practical guidance
- Choose glass-jarred fish when available. Wild Planet and Vital Choice both offer glass-jarred wild salmon. Expensive but lowest exposure.
- If buying canned, choose smaller fish. Sardines and anchovies are nutrient-dense, low-mercury, low-microplastic options often packed in glass-style jars.
- Avoid pouch tuna. The PE-laminated foil pouch adds plastic exposure. Glass > can > pouch.
- Limit albacore and yellowfin tuna to 1x/week max. Bluefin should be rare or avoided.
- Skip tuna entirely during pregnancy — see our pregnancy guide for safe seafood recommendations.
- Drain liquid before eating if buying canned — the oil/water carries the most concentrated plasticiser migration.
- Decant remaining fish to glass if not eating the whole can; storing opened canned fish in the can extends plastic-contact time.
See related: microplastics in seafood, microplastics in canned food, and microplastics in sushi.
What the MicroPlastics app checks
- Packaging material — PET, HDPE, PP, PS, multi-layer, glass, aluminum.
- Container condition from the photo — scratches, dents, fade.
- Product category — fresh, packaged, canned, frozen, takeout.
- Use-context flags you log — microwave, heat, reuse, time stored.
- Cited research behind the 0–100 risk score.
Use the App
Use the app as a grocery-store second opinion
Scan the product, check the packaging score, compare alternatives. The app weighs material, condition, brand, and the cited research.
Scan groceries in the appFrequently Asked Questions
Is canned tuna high in microplastics?
Canned tuna combines fish-borne microplastics (concentrated through bioaccumulation up the food chain) with can-liner BPA/BPS migration. Larger tuna (bluefin, yellowfin, albacore) have higher exposure than smaller light skipjack tuna or sardines.
Are pouch tuna products safer than canned?
No — pouch tuna is generally worse. The PE-laminated foil pouch adds polyethylene microplastic migration on top of the fish-borne particles. Steel cans (especially BPA-free) are slightly cleaner; glass-jarred fish (Wild Planet, Vital Choice) are best.
Which canned fish brand has the lowest microplastics?
Wild Planet and Vital Choice offer glass-jarred wild salmon — zero can-liner exposure. Among canned options, Wild Planet, Safe Catch (mercury-tested), and any brand using BPA-NI (non-intent) can liners are better than standard BPA cans. Sardines and anchovies are lower than tuna regardless of brand.
Is BPA-free canned tuna safe?
Better than BPA, but BPA-free cans typically use BPS or BPF as replacements — chemicals with similar endocrine-disrupting activity per EFSA's 2023 re-evaluation. Glass-jarred fish is the only fully plasticiser-free option for canned-style seafood.
How often is it safe to eat canned tuna?
For general adults: light skipjack tuna 1-2x per week max, albacore "white" tuna 1x per week max, yellowfin/bluefin tuna 1-2x per month or less. Pregnant women, nursing mothers, and children should avoid high-mercury tuna entirely. Sardines and salmon are safer 2-3x per week.
Can I just eat fresh fish instead?
Yes — fresh wild-caught fish from a fishmonger avoids both can liner exposure and the long shelf-life plastic migration. Smaller fish (sardines, mackerel, herring) and wild salmon are the cleanest fresh options. Avoid farmed salmon, which has separate concerns around feed contamination.
Sources
- Smith M, Love DC, Rochman CM, Neff RA (2018). Microplastics in Seafood and the Implications for Human Health. Current Environmental Health Reports.
- European Food Safety Authority (2023). Re-evaluation of bisphenol A (BPA). EFSA Journal.
- US Food and Drug Administration (2024). Mercury Levels in Commercial Fish and Shellfish (1990-2012). FDA.
- Consumer Reports (2022). Canned tuna mercury and BPA testing. Consumer Reports.
Start Scanning Your Products Today
Download the MicroPlastics app and instantly check any product for microplastic content. Free to start with 5 scans.
Download for iOSRelated Research
Microplastics in Chocolate: From Cocoa Soils to Foil Wrappers
Microplastics enter chocolate through cocoa cultivation, processing equipment, and plastic-lined wrappers. Here is what studies show and how to choose cleaner chocolate.
Read moreMicroplastics in Kombucha: Brewing Vessels, Bottles & SCOBYs
Most commercial kombucha ships in glass — but home-brew plastic vessels, plastic-lined bottle caps, and acidic fermentation accelerate microplastic leaching.
Read moreMicroplastics in Protein Powder: Tubs, Sachets, and Shakers
Protein powder is exposed to plastic at every stage — tub liners, sachets, and plastic shaker bottles. Here is what to look for and which formats are cleanest.
Read more