Processors brace for stricter listeria limits as contamination rises in raw fish.
The prevalence of Listeria monocytogenes in raw salmon has increased significantly over the past three years, according to internal data compiled by Polish processor Milarex and seen by SalmonBusiness.
In Norwegian salmon, listeria detection rates rose from 1.7% in 2022 to 3.6% in 2024. Scottish salmon showed a steeper increase, from 3.8% to 12.3% over the same period. Icelandic salmon peaked at 9.8% in 2023, before declining to 4.4% in 2024.
The Scottish and Icelandic salmon figures in the Milarex data appear significantly more alarming at first glance, however, it’s important to note that these percentages are based on relatively small sample sizes—just 130 Scottish samples in 2022, 64 in 2023, and 81 in 2024. By comparison, Norwegian salmon was tested at far larger volumes, with over 1,200 to 1,700 samples analysed each year.
“These data show that the expectation of zero detection in raw material is not met and has been moving in the wrong direction,” Milarex wrote.
The findings, based on 6,538 batches of raw material tested between 2022 and 2024, will be presented this week at the Seafood Expo Global in Barcelona. Milarex applies a zero-tolerance policy for listeria in raw material delivered to its plants, although “some deliveries are accepted and processed with corrective actions due to business and supply continuity reasons.”
For finished ready-to-eat (RTE) products, Milarex reported an increase in listeria detection from 0.11% in 2022 to 0.72% in 2024, adding that “every single deviation results in rework or disposal.”
The report also anticipates challenges ahead as the industry prepares for Regulation (EU) 2024/2895, which will apply from 1 July 2026. Under the revised standard, companies must either ensure listeria cannot grow beyond 100 cfu/g by end of shelf life or demonstrate “absence in 25g” throughout shelf life — a stricter requirement than previously enforced.
“Producers of RTE food will have to choose between setting up a shelf-life study including a challenge test, predictive modelling and durability study, or prove the absence of L. monocytogenes during the full shelf life,” Milarex wrote.
The company is urging the industry to take stronger action at source. “We believe that we need to be more transparent in the industry and work closer with raw material suppliers to implement the necessary changes,” the document reads. “A fundamental improvement must come from better raw material quality and microbiological control in the value chain.”
Milarex noted that it has “successfully worked with several suppliers on improvements” and continues to invest in shelf-life testing, environmental sampling, and monitoring to meet the expected regulatory shift.