Food: Meaning of OU-Fish?

I understand that the OU symbol is used to identify kosher foods, but what is the meaning to OU-Fish? Fish is considered neither milk nor meat; therefore, it can be eaten with anything. Furthermore, the OU-Fish symbol is so rarely found. So, what is the point to the OU-Fish on the label of certain foods?

Simplistic answer: fish can be eaten at the same meal as either dairy or meat, but fish can’t be on the same plate as meat. I don’t keep kosher, so I’m sure somebody else will come along with a more detailed answer than mine.

Fish can be on the same plate as meat. I’ve never seen OU Fish before but I grew up kosher and am familiar with checking labels. Not all fish are kosher (must have scales for example), so it may indicate a kosher fish. Alternatively, it may indicate that it’s a kosher food that contains fish (as some kosher food is marked dairy or parve) for vegetarians. If it was just marked parve, a vegetarian may think it had no animal products in it.

Was this a whole fish, or a prepared product containing fish? Where you saw it might help explaining it.

Ponch8 is correct, but to clarify: it is not a kosher restriction, it is a Talmudic-era “health” practice to not have fish and meat simultaneously without eating something else (preferably some bread and wine) in between. This practice has persisted into the modern age even though there’s no scientific basis for believing the combination to be dangerous, so the OU makes sure that kosher-observant Jews are aware of fish content in products.

This is the reason why at many Orthodox Jewish Shabbat tables, there will be a fish appetizer, followed by a “l’chayim” of wine or other liquor, only then followed by the meat main dish.

I’m guessing the product on which the OP saw this label is Worcestershire Sauce.

Is there a scientific basis to any Kosher rules?

Well, there’s that trichinosis thing with pork. And slaughtered meat has to be inspected for signs of some diseases before it’s okay to eat. The latter might not matter much in the US now where there’s an FDA, but in other times and in other countries, it could.

No, but kosher laws aren’t making a testable claim.

Isamu:

There doesn’t have to be, because Kosher is a matter of commandment from G-d, not a health practice. But if a certain food (or combination thereof) is condemned because it’s said to be unhealthy, and not because G-d said it should be banned, I’d expect there to be some basis for the belief.

Not trying to be obtuse, but… so there are Kosher rules, and then separate rules that are not about Kosher, but are about health?

OK, I’ve got it now - wikipedia and the above posts were helpful. Thanks.

It may be for allergies as well. People could be allergic to fish, but not to other parve foods, in which case, you’ll probably see parve-eggs too.

But it may be for vegetarians. A lot of goyim vegetarians are part of the market for hekshered foods, and it’s worth the while of the certifying boards to keep that in mind-- it can be a selling point: "Use our heksher, because in addition to out large Jewish following, we have a large gentile following as well.

There’s one other possibility if the product contains gelatin, Jews will automatically reject it, and scratch their hands over the heksher. The “fish” prompts them to remember that “Yes, there is fish gelatin.”