Is the gray layer next to the skin in salmon good to eat? Should it be avoided?

you can eat it. In fact a lot of the vitamins and other essential nutrients that make fish an important part of most diets is stored there.

Cook’s Illustrated says it’s fine to eat. If I recall it does contain lots of omega-3 fatty acids or whatever it is in fish that makes them healthy.

It is fine to eat. Said to be the most nutritious part of the fish. If by “waste” you mean poop, no it’s not that.

I eat it – I’m still alive!

I don’t eat it myself. Just because it’s grey and kind of slimy but that’s just me. I probably should, but I can’t.

It’s fat. Therefore it’s tasty. The fact that it’s grey is strange, but not meaningful. Enjoy!

There is no part of the salmon, including the bone and the head, which are not safe to eat. It does not all taste good so avoid any parts you don’t like. Many people DO like the part you mention. I do.

Here is a link to some answers. It seems to support the posts above.
http://newsletter.vitalchoice.com/e_article001395559.cfm?x=b4V1KpQ,b2Jwwny2,w

I loved the slimy gray part when I used to eat fish my dad caught.
But I had salmon (fresh) once and hated it. I want to like it since most people do and it’s so nutritious (I think).