Hygienic handling for raw oysters

Raw oysters

　From a long time ago, raw oysters have been enjoyed by many as a nutritious delicacy of the winter season.
　Recently, natural rock oysters go on the market as so-called “summer oysters” and this increases the opportunities for them to be consumed in another season other than the winter. In addition, oysters to be eaten raw have been imported from the U.S., Australia, New Zealand, and other countries.
　Regarding raw oysters,there are categories of “Oysters to be eaten raw”and “Oysters to be cooked.”

　In order to prevent food poisoning from raw oysters, standards and requirements, such as ingredient standards for oysters to be eaten raw, have been established.
　The Tokyo Metropolitan Government has established “Guidelines on oyster handling” to set out compliance items for business operators in order to prevent occurrences of food poisoning.
　At present, the Food Sanitation Act has been revised to systematize the “Food management in accordance with HACCP” for food handling business operators. Therefore, the guidelines were repealed on May 31, 2021.
　In harmony with this, the notification of handling oysters to be eaten raw, which was submitted annually, is no longer required.

　It is requested that business operators that handle oysters refer to the hygiene management items that have been observed so far and take measures such as including these hygiene management items in their hygiene management plans or hygiene management manuals to prevent the occurrence of food poisoning due to eating raw oysters or secondary contamination as a result of handling oysters.

[References] Important points for hygienic handling of raw oysters
Standards and requirements such as the ingredient standards are established for oysters to be eaten raw. Handling in compliance with them is required.
<Cautionary points for handling raw oysters>
○ Strict observance of storage standards for oysters to be eaten raw and frozen oysters to be eaten raw.
○ Estimate the sales volume and handle the appropriate amount of oysters to maintain freshness.
○ Handle only oysters properly labeled and be sure to sell out before the labeled expiration date.
○ Handle raw oysters properly, including washing hands
both before and after the work and using dedicated equipment to avoid contamination through staff members or drippings from the oysters.
○ Create and keep purchase and sales records.

<Cautionary points regarding selling raw oysters>
○ Set up separate sales sections for oysters to be eaten raw and oysters to be cooked so as to avoid any misunderstanding on the part of consumers.
○ Shucked oysters to be eaten raw should be sold in their originally packaged form prepared by the processor.

Main contents of the standards and requirements for oysters to be eaten raw

1. Ingredient standards

• The number of bacteria must be 50,000 or below per gram
• E. coli MPN* (Most Probable Number) must be 230 or below per 100 grams
• The MPN of Vibrio parahaemolyticus for shucked oysters to be eaten raw must be 100 or below per gram
  
  * MPN (Most Probable Number) is a method to calculate the number of bacteria using an "MPN table" obtained experimentally from the number of positive test tubes cultured in diluted solutions in steps such as 10 times to 100 times.

2. Process standards

　　　　 (omitted)

3. Preservation standards

• Preserve at 10℃ or lower. For frozen oysters to be eaten raw, preserve at -15℃ or lower.
• Oysters to be eaten raw must be put in a clean and hygienic container with a lid or wrapped with aluminum foil or waterproof-coated paper for storage. However, frozen oysters to be eaten raw must be wrapped with clean and hygienic synthetic resin, aluminum foil, or waterproof-coated paper for storage.

▲ Page top