On the farm growing up we used to kosher granulated stuff. Then as a hobby producer my friends and I used evaporated milk it was cheap u poke a hole in the can and one drop took care of the foam. When I went on my own and started selling I went with the Atmos defoamer just because it was FAD approved and readily available, virtually every distributor has it on the shelf. I have however always been kind of concerned about what's in it.

I realize the ppm that would end up in the syrup is very low but as others have said the same is true for Butter fat or animal fat.
I know one guy who uses unsalted butter and I really don't see anything wrong with it. If I have people in the shack and I'm Boiling and they see me adding atmos it always ends up with a long conversation about it depending on the vistor. Seems like if you just had a little butter or something like that it's pretty hard to argue with what it is.

Maybe someone knows exactly what's in the Atmos and why it's FDA approved and could explain it better.