Fume Cupboards are certified by SIRIM QAS international SDN BHD to the reference standard of ANSI / ASHRAE 110-1995 using the method of testing performance of Laboratory Fume Hood 

Report No. 2011MA0597

 Perchloric Acid Fume Cupboard with scrubber unit is used in the removal of acid fumes. It is commonly used in conjunction with the LABOFF fume cupboard, although it can be used in other scrubbing functions as well. It consist essentially of layers of pads to seperate and trap fume particles (hydrofluoric and perchloric acid), to allow them to be scrubbed. The system shall be designed to meet minimum 98% efficiency and pressure drop not exceeding 2 in. wg by having >98% voidage.

The principle of operation is that the fume shall initially be wet by the liquid spray as it passes through the lower pad at a predetermined velocity which depends upon the relative densities of the fume and the liquid. The droplets laden gas impinges on the filament of the pad where the droplets coalese and accumulate, eventually growing to such a size that they drain down and out of the pad against the direction of the gas flow and fall back into the liquid below. The top layer servers to eliminate any moisture vapour. The gas free of any suspended liquid particles passes out from the top of the pad.