Can plastic boxes be used in these areas?

Yes, see the UL listing(s)for the boxes in question.

Roger

One could also look inside the boxes and in most cases it will have lettering that will say "2 HR W C". In that case it would be suitable for a 2 hour rating in a wall or ceiling. I would qualify my statment by saying that is what I typically see in a non-metalic box used for NM cable. There would possibly be other ratings for other boxes.

typo's

[This message has been edited by George Little (edited 06-07-2006).]

Thanks for the info. Now how about the cover? I need to use a blank plate on a round plastic nail-on box. I looked at the Arlington plastic blank plate and I don't see a rating on it. Do I need to use a metal blank-up plate? I rather use the pastic one it is white like the ceiling.

Gserve:
Just had this discussion with UL (Northbrook, Il) today, regarding 'extensions' in fire rated ceiling.

Per the White Book, 'ANY' type of plate can be installed on the rated boxes, as long as the boxes are installed to mfg/UL specs.

My inquiry related to extensions on deep set boxes, 2 hr rated ceiling; answer was yes, Arlington BE-1R is OK (4" round), but, BE-1 for 1-gang device is not. Go figure??

John