Part i : tb lab services: diagram 1

DECONTAMINATION OF BSC BEFORE REMOVING FILTERS AND AFTER LABORATORY ACCIDENTS
Procedure:

Remove all material and equipment from the BSC and from the immediate environment. Ensure that the BSC is switched on

Seal all air intake and exhaust grills in the laboratory by taping large plastic garbage bags over the  grills. Also tape around door frames or other openings through which the formaldehyde  vapour may leak

Use 25ml of a  40% formaldehyde solution and 15g potassium permanganate for each cubic meter capacity that has to be decontaminated: Place the potassium permanganate crystals in a deep metal container in the BSC. Pour the formaldehyde solution over the crystals and leave the laboratory immediately since the reaction rapidly produces the release of heat and formaldehyde  gas. Close and seal the laboratory door

Allow the  formaldehyde vapour to act overnight (and preferably over a weekend), with the BSC being  switched on

Remove the covers from air intake and exhaust grills as well as the tape around doors and other openings. Allow the  room to air until no more formaldehyde is detectable, then mop all residue from the floors, walls and benches. If a white, powdery residue is obvious, remove by wiping with a  10% ammonium hydroxide solution (use gloves)

Switch the BSC off and proceed with replacement of filters or repair