In my 6,000+ hours (thumps chest) in the CRJ-200, I would not say it is unsafe at 40 or 41. I would say you need to have some experience in determining if it is going to make it up there by the mid-30's, so you don't put yourself in a bad situation above 390. That said, I think I made it to 40 one time in 9 years. Unless it is very cold and a lite load, forget about it.