Access Control and Security Systems, on May 15, has an article on the possible problems of a "smoke cloaking" security system. "The International Association of Fire Chiefs, Fairfax, Va., is concerned about a new burglar alarm system that deploys dense smoke to incapacitate an intruder. The systems are sold on the premise of protecting a property by having a blinding smoke screen quickly fill an area when a burglar alarm is activated. In turn, the blinding smoke may likely activate a smoke/fire alarm; this would precipitate a fire department response."

For those of you not familiar with how that system may function, The brief movie shown below - from a demo I received in June, 2003 from Arias Tech Ltd, on the "SmokeCloak" system, provides and effective demonstration of how the smoke system works: Smoke Cloaking

Notwithstanding some of the objections shown in the Access Control article, there are probably some good locations for the use of security devices such as this one. If you think your facility hmay have a need for an active security device of this type, it may behoove you to fully examine those systems.