Butter is actually quite low in lactose content (like 9x less than milk) and the serving size is relatively small: https://en.wikipedia.org/wiki/Lactose_intolerance#:~:text=Ty...

So generally butter is not a problem for people with lactose intolerance anyway.

I do want to point out that this is not about lactose intolerance. This is about a milk allergy. Different things. Upset tummy vs anaphylaxis.

But the recommendation to throw it out is insane. There's nothing wrong with it besides the label. And what person who can't eat dairy is running around buying butter?

I guess people who bought it and can't use it could exchange it, and you have to throw that out because it lost the chain of cold, but the ones in the shelves? Simply putting a [CONTAINS MILK] sticker on each package should be less wasteful, but the ways of retail might have mysteries I ignore.

Imagine the labor required to individually sticker 47000 individual boxes of butter (approximately an entire 53' trailer) vs. just setting it aside for your regular food waste recycler to pick up. That's the equation they'd be looking at.

Devices to add stickers to packages was a solved problem before food allergy warning labels existed. In the 1980s supermarkets made money adding price stickers to every item of inventory, then changing the prices for sales. Meanwhile the food waste recycler (may not exist in your area, some exclusions apply) needs to remove all of the foil wrappers to the butter before recycling.

There’s a clear winner, unless you’re trying to send some kind of message to the supplier.

Nah, your food waste recycler is already picking up from your facilities weekly+ and all they're going to do with your pallet of butter is tip it into the depackager and wait.

I suspect that stickers might not be approved by whoever did the graphic design on the packaging.

It was Kirkland butter, I hope they are allowed to stain the artistic expression of their own design.

Or just ask Costco to slap a "Contains Milk" sticker on it?