They may be safe to eat, but they also may not be safe to eat. The designation, IIRC it is ‘Unfit for Human Consumption’, is a choice by the operator that can be applied to anything from broken pieces of food to containing rat poison. I assume if something found at the grocery store is labeled that way that a supplier has specified they are safe to eat in some other way. I would never eat anything labeled that way myself, but go ahead and take your chances if you like. I’m frankly surprised food with that designation would be sold in a grocery store.
ETA: I’m seeing ‘Not Fit for Human Consumption’ and ‘Not for Human Consumption’ hits from a search. Also a lot of state specific specifics. I Don’t get to use ‘specific specifics’ in a sentence very often.
It can just mean that nobody’s verified their safety. In which case they’re probably OK, but you don’t know. Or it can mean that someone absolutely definitely knows they’re not safe.
The FDA has a number of regulations that define the requirements of food that is fit for human consumption. As far as I can tell any labeling that says “Not for human consumption” or something similar means the product either does not meet the requirements, or hasn’t been checked for meeting the requirements of food fit for human consumption. Such products may even meet the requirements for Human Food Byproducts for use as Animal Food, or many other defined regulations.
So they sell these fish in a market and they’re labelled “not for human consumption”? What kind of market is this? Are they selling bait fish, or food for pets or for a zoo?
IIRC this was the case a while ago (still?) for example for fish from Lake Erie (and probably anything downriver of Detroit?) The problem was assorted chemical contaminants. Or it could be sewage
The issue was summed up in a political cartoon in the 1970’s: Person A: “Industry has polluted Lake Erie so much that the fish are not safe to eat. What should the government do?” Person B: “Ban fishing!”
Also, there were problems with fish in northern Ontario due to pulp mills - they used mercury as part of the process because it was harmless and would not escape into the waterways. A number of natives suffered from mercury poisoning in the decades since and the natives have been told not to eat their local fish, which was a major source of food.
I suspect a number of waterway have similar problems.
The issue may be that the fish are too contaminated for long-lived humans to eat; or there is a risk of that; or they simply haven’t been tested.
We’ve been doing lots of training with our dogs. My gf bought some new treats, and they were clearly marked as not for human consumption. I was tempted, but haven’t tried one.
If the herring are not for human consumption, is there any indication on the packaging what purpose they are intended for? Pet food? Bait? Cutting down the mightiest tree in the forest?
I don’t know about fish but I do know the USDA considers animal lungs to be “unfit for use as human food,” even though there is no known health risks of eating lungs and they are fairly often (and legally) eaten in Europe. The federal regulation explains why you can’t get a proper haggis or Beuschel (German lung-and-heart stew) in this country unless you slaughter your own animals.
Generally fish and seafood is regulated by the FDA, not the USDA. I don’t know if the FDA is more rational with their rules.