I'm in the process of removing several flush mounted ceiling lights, to be replaced with can lights, and have run into a situation that I wanted to get a second opinion on. In one of the areas where I am replacing the old light, i've found that there is a stretch of soft, flexible, insulated duct work for the HVAC system right where the housing for the can needs to go. It's covered with the thin, aluminum foil looking stuff. I can shove the duct work to the side and out of the way to make room for the can, but the space is so tight that the duct work will essentially be pushed back up against the side of the housing. I have an IC rated can, and was just wondering if it's safe to have the can and the duct touching each other.

Should be perfectly fine. Insulation Contact - key word contact.

I'd be more worried about the mechanics of having ductwork touching a light fixture... vibration from the HVAC system, constant pressure on a fixture which might eventually move it out of alignment, etc.

Yep, it's safe.

Thanks guys.