Fumigation of microbiological safety cabinets

摘要

A cabinet, which is to be fumigated, comprises a housing 10 defining a chamber 12 having an opening closable by a panel 20, an exhaust duct 22 leading from an outlet 15 of the chamber, a filter 26 across the outlet, an extractor fan 25 in the exhaust duct, a vaporiser (not shown), an additional aperture 29 with electrically actuable closure means 30 and electronic control means (not shown). The control means controls the sequence of fumigation operations including the length of time the vaporiser is switched on, the time interval before the extractor fan is activated and the time interval between opening and closing the additional aperture (to allow air into the housing). Preferably the housing also contains an upper chamber 14 having a recirculation fan 19 with a filter between the chamber 12,14 so that, in use, air can be recirculated from chamber 12 via a return duct 18 to chamber 14.