CDC Report: Why Cooking Cannot Make Toxin-Contaminated Seafood Safe

A new CDC surveillance summary puts an often-missed seafood question back on the kitchen checklist: what can you do when the hazard is a toxin rather than a live bacterium? The answer is important for anyone who buys fish, cooks shellfish or brings home a catch. Marine toxins can be tasteless and odorless, and the CDC says that ordinary cooking or freezing does not make contaminated seafood safe.

What the CDC found

The report reviews foodborne outbreaks recorded in the United States from 2011 through 2023. It identified 402 outbreaks associated with marine toxins, involving 1,280 illnesses, 96 hospitalizations and one death. Two categories dominated the dataset: scombroid toxin was linked to 192 outbreaks, while ciguatoxin was linked to 189. The report also records shellfish toxins, puffer-fish tetrodotoxin and other less common causes.

The distinction matters because these hazards do not all begin in the same place. Some toxins are produced by algae and accumulate in fish or shellfish through the food chain. Others are associated with poor food storage. The report also notes that harmful algal blooms have occurred on both US coasts and that the historical range of some toxin-producing species has expanded. This is surveillance data, not a claim that every fish or shellfish product is unsafe, but it is a clear reminder that a hot pan cannot solve every food-safety problem.

Why a high cooking temperature is not a universal fix

Home cooks are rightly taught to use a thermometer, separate raw foods and keep perishable ingredients cold. Those steps remain essential for controlling many bacterial hazards. Marine toxins are different. The CDC's prevention guidance says algal toxins in fish or shellfish have no taste or smell, and that cooking or preserving food does not remove them. The same guidance warns that you cannot decide whether seafood is safe simply by looking at, smelling or tasting it.

That means frying, grilling, steaming or freezing should never be treated as a rescue method for seafood from a closed harvest area, an unverified source or a known advisory. It also means that a food thermometer, while useful for ordinary cooking safety, cannot detect a marine toxin. If the concern is a toxin, the decisive control is choosing seafood from an approved source and following the current advice for the place where it was harvested.

A practical seafood check before dinner

Check the source first. For fish or shellfish you catch yourself, look up the current local fishing and shellfish advisories before cooking. Harvesting closures exist because official testing has found unsafe conditions. Do not rely on a clear-looking shoreline or on the fact that another person has eaten from the same area.
Be more cautious when travelling. The CDC advises travellers outside the United States to avoid large reef fish such as barracuda, grouper and amberjack, which can carry ciguatera toxin. It also specifically advises avoiding the head, gut, liver and roe of large reef fish. These are targeted precautions, not a reason to avoid all seafood.
Keep cold-chain habits, but know their limits. Fish still needs careful refrigeration and prompt handling because poor storage can create additional hazards, including scombroid toxin. Chilling protects quality and slows bacterial growth; it does not reverse contamination that has already occurred. If a product is covered by a recall or advisory, do not try to make it safe by cooking it longer.
Do not taste-test questionable seafood. Because some toxins have no reliable taste or smell, tasting a small portion is not a safety check. When in doubt about a harvest notice, product history or recall, stop and verify the information with the relevant food-safety authority.

What to do with an advisory

The most useful habit is to check before the seafood reaches the pan. The CDC says state officials close shellfish harvesting areas when testing shows shellfish are unsafe, and advises consumers to follow local advisories for self-caught fish and shellfish. For purchased seafood, use established retailers and keep the label or receipt until the meal is finished, so you can respond quickly if an official recall appears.

Do not confuse a marine-toxin advisory with a normal use-by decision. A product can look fresh and still be unsafe if it comes from a closed area; conversely, a routine cooking step can still be necessary even when no toxin warning exists. The controls answer different questions: sourcing and advisories address toxins, while refrigeration, hygiene and adequate cooking address other food-safety hazards.

The kitchen takeaway

The CDC's new report is useful because it makes the limit of “just cook it thoroughly” explicit. For marine toxins, prevention happens upstream: check the harvest status, choose a traceable source, handle seafood cold and follow local or national advice. Once a toxin is present, the oven, grill and freezer are not guaranteed solutions. If someone becomes ill after eating suspect seafood, seek medical advice and mention the seafood exposure. A safer seafood dinner starts before the recipe, with a quick check of where the food came from and whether officials say it is safe to eat.