Although, reduced oxygen packing (ROP) of frozen seafood allows for an extended shelf-life in the freezer, one must be careful while thawing. This is especially important to prevent seafood poisoning from Clostridium botulinum. Clostridium botulinum is a Gram-positive, anaerobic, and spore-forming bacterium that produces the deadly neurotoxin botulinum. If ROP seafood products are not properly stored and/or thawed as per the instructions, then the sealed ROP provides an excellent condition for C. botulinum spores to germinate and then produce botulinum toxins. Although, it is relatively rare, foodborne botulism causes a fatal disease. This is the reason why all the frozen seafood products in sealed ROP must have a safe handling instructions stating: Important: keep frozen until used. Thaw under refrigeration immediately before use. Remove from the vacuum package before thawing.

What are the benefits of ROP of frozen seafood?

The ROP prevents the growth of pathogenic microorganisms besides reducing fat oxidation and rancidity, thus extending the shelf-life of the frozen seafoods.

What are the conditions under which C. botulinum can multiply and become a risk to the consumer?

Clostridium botulinum produces heat stable botulinum toxins under ROP conditions and when exposed to above 38°F.

When was the thawing instructions added to frozen seafood packages?

Modification to the already existing section 3-501.13 (thawing), in the 2009 Food Code (as modified by the supplement issued in 2012) was amended in 2013. This represents the Food and Drug Administration’s current thinking on this topic. So it would be appropriate for the manufacturers to comply this rule based on the risk assessment and seafood HACCP requirement.

How long does it take for the C. botulinum to form toxins that causes potential health risk to consumers?

C. botulinum spores produces toxin very slowly at lower temperatures and more rapidly at elevated temperatures. At 38°F, it takes over 20 days to form toxins, at 50°F it takes only 2.5 days, and it is capable of producing toxin in < 2 hours at 95°F. So it's critical to manage the amount of time when a vacuum sealed frozen seafood is exposed to elevated temperatures (>38 °F) during thawing. Additionally leaving seafood, which is rich in nutrient composition, out too long at room temperature can cause other pathogenic bacteria (e.g., L. monocytogenes) multiply to dangerous levels that can cause illness upon consumption.