Biological Safety Cabinets Types of Biological Safety Cabinets

Biological Safety Cabinets

Types of Biological Safety Cabinets • Biological safety cabinets – Class III

Class I Biological safety cabinets – Open fronted – Negative-pressure ventilated cabinet – Provides only worker protection NOT product protection

Class II Biological safety cabinets - Negative-pressure ventilated cabinet – Provides High efficiency particulate air (HEPA)-filtered, recirculated airflow within the cabinet – Exhaust air is HEPA-filtered – Provides personnel and product protection • Types of Class II BSCs – Class II A: HEPA filtered air is discharged into the room – Class II B: HEPA filtered air is discharged out of the room – Class II A/B: Can be used either way.

Class III BSC 1. Ventilated cabinet - totally enclosed 2. Gas tight construction 3. Operations are conducted through attached rubber gloves. 4. Both supply and exhaust air are HEPA-filtered 5. Provides both personnel and product protection Ambient Air Contaminated Air HEPA Filter

Safe work habits in a Class II BSC – Laboratory coats and latex gloves should always be used – Adjust the stool height so that your face is above the front opening

Safe work habits in a Class II BSC – The cabinet blower should be operated at least 3 to 5 minutes before you begin work – Manipulation of materials should be delayed for about 1 minute after placing your hands and arms inside the cabinet – All manipulations should be at least 10 cm from the front grille

Safe work habits in a Class II BSC The front and back grilles should not be blocked with equipment, notes, supplies

Safe work habits in a Class II BSC • Materials or equipment placed inside the cabinet can disrupt airflow – don’t do this! • Frequent movement of your arms in and out of the cabinet will disrupt the integrity of the air barrier

Safe work habits in a Class II BSC Use a smaller biohazard bag in the cabinet

Safe work habits in a Class II BSC • Open flames (Bunsen burners) are not allowed in a microbe-free environment of a BSC • Open flames actually creates turbulence that disrupts the air flow

Decontamination of BSCs All surfaces should be wiped down with a disinfectant at the end of any procedure • 70% Ethanol (ETOH) is the most commonly used disinfectant • Many people use 0. 05% sodium hypochlorite (Clorox or bleach) but remember this is very corrosive to stainless steel, need to wipe off residual bleach with water