Why do I have to remove fish from package before thawing?

Chef's answer
By opening the packaging when thawing the vacuum packaged fish, oxygen is present and the spores will not produce the vegetative cells that produce the toxin. Listeria monocytogenes is a bacterium that can contaminate food. ... Unlike many bacteria, Listeria can grow and multiply in some foods in the refrigerator.
Frequently asked Questions 🎓
Yes. Most hot dogs are pre-cooked prior to their being packaged. Only absolutely fresh hot dogs such as you would get directly from a butcher shoppe are not pre-cooked..
While not a safety issue, be aware that placing packaging in your sous vide water bath will usually strip off all labels affixed to it. These labels can get caught up in your sous vide machine and should be removed before cooking..
Clostridium botulinum and Listeria monocytogenes are the bacteria of primary concern when thawing vacuum packed fish. ... In order to prevent the production of the toxin, Michigan State University Extension advises it is important to keep food such as fish that is vacuum packaged (no oxygen) at the proper temperature.
A few more cooking questions 📍