A recent study conducted in Bulgaria found that nearly a quarter of fish foods from four Sofia commercial establishments had elevated levels of histamine, with one sample exceeding the EU's limit by more than 10 times. The samples included both fresh and frozen fish, with most assumed to be imported. The study also highlighted labeling issues with six out of 13 foods, missing crucial information such as expiration date and country of origin. Histamine is a compound that accumulates in fish due to bacterial growth, and its accumulation can lead to poisoning, which can mimic an allergy. The study emphasizes the importance of temperature control and correct labeling in the processing, transport, and storage of seafood.