I agree with the statements above. Food borne illness is a serious risk in our world today. One must take care to be safer. But relying on a shiney knife alone to keep you safe is like wearing a very expensive helmet when skydiving with a hello kitty backpack for a parachute...
Again, I submit the example of a cutting board (of wood, bamboo, plastic, or other typical materials used). Unless they are only a one use, disposable item, I’d like to see how they compare to a rough finish knife for the potential of trapping harmful bacteria. I look at my cutting boards (that do not get a tiny fraction of the use one might get in a commercial setting), I see hundreds of tiny cuts that could hold literally billions of bacteria. Of course I scrub my cutting boards and knives with a stiff brush, and I use bleach after cutting poultry or other meat. I don’t see the health department banning their use, but they probably do have something to say about use and cleaning.
I just believe that a knife with a rough finish would be much easier to clean/sanitize than a soft and/or permeable surface of a cutting board.
I understand health department rules, but they are practically overzealous. That is to say they have to be stringent, out of an abundance of caution, and because if there were little or no standards, some commercial food handlers would not practice any kind of safety or food borne illness prevention at all.