Import Alert 16-125: Detention without physical examination of refrigerated (not frozen with proper labeling) raw fish and fishery products in reduced oxygen packaging due to the potential for Clostridium botulinum toxin production

FDA considers packaging with an oxygen transmission rate (OTR) of 10,000 cc/m2/24hrs at 24°C (75°F), or higher to be oxygen-permeable packaging for fishery products and is not considered ROP. Oxygen-permeable packaging should provide a sufficient exchange of oxygen to allow naturally occurring aerobic spoilage organisms on the fishery product to grow and spoil the product before C. botulinum toxin is produced under moderate abuse temperatures. Use of an oxygen-permeable package may not compensate for the restriction to oxygen exchange created by practices such as packing in oil or the use of oxygen scavengers in the packaging.

For eviscerated fish and fishery products in ROP, refrigeration alone is not sufficient to control C. botulinum throughout distribution because non-proteolytic strains of C. botulinum, commonly found in seafood, can grow at 38°F (3.3°C) and above. In 1992, the National Advisory Committee for Microbiological Criteria for Foods (NACMCF) evaluated the microbiological safety issues associated with VAC/MAP refrigerated raw fishery products and found that the primary preventive measure against C. botulinum is temperature control below 38°F (3.3°C) from time of packaging through preparation. With current practices and abuses at the retail and consumer level, maintenance of a storage temperature below 38°F (3.3°C) from time of packaging to consumption is unlikely. Studies conducted by FDA in 1996 and 1997 indicate that toxin production may precede absolute spoilage and rejection by the consumer in extended shelf-life VAC/MAP raw fish at temperatures of 45°F to 50°F (7.2 °C to 10°C). Several studies indicate that temperatures between 45°F and 50°F are frequently encountered in retail storage coolers, retail display coolers, and home refrigerators. FDA considers these fish and fishery products in ROP to be a potentially life threatening, acute health hazard because when temperatures are 38°F (3.3°C) and above C. botulinum spores may germinate into vegetative cells, multiply, and produce deadly toxin.

FDA currently recommends the following as control strategies for C. botulinum in eviscerated fish and fishery products in ROP:

1. When refrigeration control below 38°F (3.3°C) is the sole control for the C. botulinum hazard, use a Time-Temperature Indicator (TTI) on each ROP package AND maintain the product below 38°F (3.3°C). Since product will likely not be maintained below 38°F (3.3°C) during distribution, TTIs are needed to monitor time and temperatures exposures throughout distribution until consumption. TTIs should be designed specifically for C. botulinum and alert consumers and end users of potentially unsafe time and temperature exposures that could result in toxin formation.

2. Freeze the product immediately after packaging, maintain the product frozen throughout distribution, and clearly label each individual package of the product to be held frozen and to be thawed under refrigeration immediately before use (e.g., "Important, keep frozen until used, thaw under refrigeration immediately before use"). The labeling should have two parts with instructions to keep the product frozen and for proper thawing. Thawing can be done in the ROP under refrigeration immediately before use or it is also acceptable for the labeling to require removal from packaging before thawing. Removing the seafood from ROP will also remove the hazard of C. botulinum growth and toxin formation. Proper labeling is critical to prevent time and temperature exposures during thawing that are conducive for botulinum toxin production. Note: These products are not subject to this import alert, if properly labeled.

3. Formulate the finished product to create a secondary barrier such as: a water activity below 0.97; or a water phase salt of at least 5%; or a pH of 5.0 or less AND maintain the product at 40°F (4.4°C) or below. Note: These products are not subject to this import alert.