Finally got some valid input about this system. Been a year and a half in the works. !. The deluge system is for control of a fire in the storage area with NO release of the chemical (methylhydrosilane). The MSDS and the info from the manufacturer state "Do Not use water on spills or leaks" It is permissable to use Ar-AFFF foam at an expansion rate of at least 30:1 or greater. There is a venting system with a neutralizier for any accidental release, and the process uses very small quantities of the material with elaborate purging procedures and vapor collection should a release occur. Someone (long since removed from the employ of the company) decided that it would be possible to flood the storage building with foam and simply places a sign at the sprinkler siamese stating that it should be supplied with AR-AFFF foam without consulting the FD as to their ability to perform this feat. Alarms initiate self closing valves on any cylinders that are on line, so this limits the possible problems within the process. We are still faced with possible handling problems, but it would be unlikely to simultaneously have a fire when changing containers. Glad we finally got some answers. FWDbuff... our code enforcement has a hard time looking at residential buildings and checking code compliance.. let alone dealing with chemicals and the resultant production of hazardous vapors. We really need to spend more time examining the MSDS as they are provided and improving communications with our industrial engineers. Quite an enlightening presentation the other night. People & officers making assumptions about how stuff is supposed to work, instead of how it really works.