Hilti (http://www.us.hilti.com/holus/modules/prcat/prca_navigation.jsp?OID=-12266) also makes fire stopping products. I specify them quite a bit and have been satisfied. The contractors seem to like them as well.
I think that Section 1104.3.4 (including the exceptions)of the 2000 International Mechanical Code outlines all items necessary to prevent the decomposition of refrigerant (i.e. boiler in the same room). They can be in the same room, but if it is a natural draft boiler you have to have a...
