Smoked salmon, with its luxurious texture, delicate flavor, and association with brunches, bagels, and hors d’oeuvres, enjoys a certain culinary prestige. It’s marketed as a refined, healthy source of protein and omega-3 fatty acids, often perched beside capers and crème fraîche in upscale delicatessens. Yet despite its gourmet status, smoked salmon—and smoked fish more broadly—harbors a quiet but persistent danger: Listeria monocytogenes, a potentially deadly bacterium that can flourish where most other foodborne pathogens cannot. Unlike Salmonella or E. coli, which typically require improper cooking or storage to become dangerous, Listeria can survive and even multiply in refrigerated environments—the very condition under which smoked salmon is typically stored and consumed without further cooking.
This unsettling truth casts a shadow over the chilled, glistening slices of fish in countless refrigerators and delicatessens. In recent years, public health officials have issued repeated warnings about the risks of Listeria in smoked fish products, especially cold-smoked varieties like lox. And for some vulnerable groups—pregnant individuals, older adults, and those with weakened immune systems—Listeria isn’t just a cautionary tale. It can be a matter of life and death.
Understanding the Smoking Process—and Its Limits
To understand why smoked salmon is especially vulnerable to Listeria contamination, it’s important to distinguish between two very different types of smoked fish: hot-smoked and cold-smoked. Hot smoking involves cooking the fish at temperatures of 145°F (63°C) or higher, which effectively kills most pathogens. Cold smoking, on the other hand, is done at much lower temperatures—usually between 70°F and 90°F (21°C to 32°C). While this imparts a rich, smoky flavor and delicate texture, it does not kill bacteria. And therein lies the problem.
Cold-smoked salmon is not a cooked product. It is cured and smoked, but never brought to a temperature that would reliably destroy harmful microorganisms. Even if the initial raw fish was free from contamination, the processing environment—particularly slicing machines, brining vats, or packaging areas—can introduce Listeria, which can persist in production facilities for months or even years if not adequately controlled.
Listeria monocytogenes is particularly insidious. Unlike most other foodborne pathogens, it thrives in cold, moist environments. Refrigeration—typically a reliable food safety strategy—is no match for Listeria. Once it enters a facility or a food product, it can quietly multiply, even at temperatures below 40°F (4°C). This unique ability makes cold-smoked fish an ideal vector for the bacteria, especially when vacuum-packed and stored for extended periods.
The Real-World Toll: Outbreaks and Recalls
The theoretical risk of Listeria contamination in smoked salmon isn’t just a laboratory concern. It has played out in multiple real-world outbreaks and recalls, often with devastating consequences.
In 2018, a large-scale outbreak of Listeria linked to smoked salmon products swept through several countries in Europe. The same strain was identified in patients over a span of years, ultimately traced to a single Polish production facility. It was responsible for over two dozen illnesses and several deaths, many in elderly or immunocompromised patients. The outbreak persisted in part because Listeria had established a foothold in the processing equipment itself—specifically in a slicer used for portioning the smoked salmon before packaging. That slicer, like many in the industry, was nearly impossible to sanitize completely without full disassembly.
Closer to home, the United States has had its own encounters with contaminated smoked fish. In 2021, Banner Smoked Fish, Inc. recalled a wide variety of smoked fish products—including salmon, trout, and whitefish—due to Listeria contamination concerns. While no illnesses were reported at the time of the recall, the threat was real enough to prompt the voluntary withdrawal of more than forty products. Even when outbreaks don’t emerge, contamination events serve as grim reminders of the challenges involved in keeping smoked fish safe.
In another case, Gravlax-style salmon sold at various specialty retailers tested positive for Listeria in random FDA inspections, prompting recalls that spanned multiple states. Such episodes are not rare. According to FDA enforcement reports, smoked fish products routinely appear on lists of recalled foods due to potential Listeria contamination. The problem is persistent and well-documented, and it’s particularly pronounced in cold-smoked fish, which lacks the thermal kill step of cooking.
Who Is Most at Risk?
While healthy adults may suffer only mild flu-like symptoms (if any) after consuming Listeria-contaminated food, vulnerable populations face far more serious outcomes. For pregnant individuals, Listeria infection (listeriosis) may appear mild but can result in miscarriage, stillbirth, or premature labor. The CDC estimates that pregnant women are about 10 times more likely to contract listeriosis than the general population. For their unborn children, the risk is even greater. One study found that about 20% of all Listeria-related pregnancy infections result in fetal loss.
Older adults—particularly those over 65—and individuals with compromised immune systems (such as cancer patients, organ transplant recipients, or those with HIV) also face significantly higher risk. In these groups, listeriosis can lead to septicemia, meningitis, and death. The fatality rate for invasive listeriosis is alarmingly high—between 15% and 30%, depending on the population and how quickly treatment is initiated.
Because Listeria has a long incubation period (ranging from a few days to 70 days), its symptoms can be delayed and its source difficult to pinpoint. Many people do not connect their illness back to a piece of smoked salmon consumed weeks earlier.
Why Regulation Isn’t Enough
Despite the known dangers, the regulatory environment around smoked fish remains something of a patchwork. In the United States, the FDA enforces a strict “zero-tolerance” policy for Listeria monocytogenes in ready-to-eat foods like smoked salmon. That means even a single cell of Listeria in a sample can trigger a recall. Yet enforcement is limited by the FDA’s capacity to inspect processing facilities, and by the inherently difficult task of eradicating Listeria once it’s established in a food plant.
Many European countries take a slightly different approach, setting maximum allowable Listeria counts (usually 100 CFU/g) in ready-to-eat products at the end of their shelf life. This assumes that the food will be properly refrigerated and consumed quickly, but it leaves some room for bacterial presence. Critics argue that such a standard is too lenient for a food item so frequently eaten without further cooking.
Meanwhile, industry best practices—such as environmental monitoring, regular equipment sanitization, and strict temperature control—are only as effective as their implementation. As shown in multiple outbreaks, even well-intentioned companies can find themselves battling entrenched Listeria colonies that resist cleaning and reappear in finished products.
What Consumers Should Know
For most consumers, smoked salmon still seems like a health-conscious and low-risk indulgence. It doesn’t look or smell spoiled. It’s often attractively packaged, sometimes labeled with terms like “organic,” “sustainably sourced,” or “artisanally smoked.” These qualities, while appealing, do nothing to mitigate the risk of Listeria.
The CDC and FDA advise high-risk individuals—pregnant women, elderly people, and those with weakened immune systems—to avoid cold-smoked fish unless it is cooked to an internal temperature of 165°F (74°C) before eating. This includes not just lox and gravlax, but also other cold-smoked fish products often served on charcuterie boards, canapés, or sushi.
Hot-smoked fish, because it is cooked during processing, carries significantly lower risk. But even then, post-processing contamination can occur if the food is handled improperly or sliced on contaminated equipment.
Freezing does not kill Listeria, and vacuum-sealing does not prevent it from multiplying. In fact, vacuum-packaged smoked fish can create the kind of low-oxygen, high-moisture environment Listeria thrives in.
For consumers who choose to enjoy smoked salmon, proper storage is crucial. It should be kept below 38°F (3.3°C), consumed quickly after opening, and never eaten past its expiration date. Repackaging it at home or transferring it to platters should be done with clean hands and sanitized surfaces.
The Uncomfortable Reality
Smoked salmon occupies a curious space in the culinary world—sophisticated, luxurious, seemingly healthy. Yet it’s also one of the most persistent sources of Listeria monocytogenes contamination, even in countries with stringent food safety standards. Public health agencies continue to wrestle with the best way to regulate it, manufacturers battle to keep their facilities free from contamination, and consumers remain largely unaware of the risks they take when they unwrap a glistening filet of lox.
The risk is not just theoretical. It is borne out in recalls, outbreaks, hospitalizations, and deaths. And it is largely preventable—either by avoiding cold-smoked fish altogether or by developing safer methods of production and stricter environmental controls. Until then, the safest bet for vulnerable consumers may be the most conservative one: avoid cold-smoked fish entirely unless it has been reheated to steaming hot.
It’s an unfortunate reality that such a beloved and refined food can carry such quiet dangers. But in the world of food safety, prestige is no protection, and refrigeration is no guarantee. In the case of smoked salmon, the delicacy may not always be worth the risk.
