Class 1E cables in cable trays

New installation in the US? Part 50 or 52? For Part 50 plants, my instinctive response is that the cable trays would need to be QA1 and that you don't run 1E and non1E cables in the same tray.
The rationale for the QA1 is so the cables would continue to do their safety function in the event of any natural phenomena, including an earthquake. The rationale for the 1E/non1E split is so a fire in a non-safety system doesn't propagate to the safety systems. However, if you're looking for a specific requirement that says "You SHALL," I'd suggest talking to your licensing folks or you could look up the code of federal regulations online.

Patricia Lougheed

A FAQ for you to consider: FAQ731-376
Translation assistance: forum1529

It's probably easier to assess your question if you indicate what the proposed alternative is?

My general understanding is that you are relying on the cable raceway to perform a safety function (structural integrity), so it should be similarly classified as the cable that runs it.