It is classified in 4 categories:
Class II, type A1: this does not have to be vented, which makes it suitable for use in laboratory rooms which cannot be ducted. This cabinet is acceptable for use of low to moderate risk agents in the absence of volatile toxic chemicals and volatile radionuclides.
Type A, has a minimum inflow velocity of 75 ft/min. The filtered makeup air is divided equally over the work surface at about two to six inches above the work surface. Exhaust is drawn at the bottom of the cabinet where it rises to the top. At the top of the cabinet, 70% of the air recirculates through the supply HEPA filter, the other 30% of air exhausted through the exhaust HEPA/ULPA filter.
This type is not safe for work with hazardous chemicals except when ducted, usually with a "thimble" or canopy hood to avoid disturbing internal air flow.
Class II, type A2: this must be vented. 70% of the air is exhausted from the cabinet while 30% is recirculated. This cabinet may be used with etiologic agents treated with minute quantities of toxic chemicals and trace quantities of radionuclides that will not interfere with work if recirculated in the down flow air.
The Type A2 cabinet, has a minimum inflow velocity of 100 ft/min. A negative air pressure plenum surrounds all contaminated plenums that are under positive pressure. In other respects, the specifications are identical to those of a Type A1 cabinet.
Class II, type B1: this cabinet must be vented, with 30% of the air exhausted from the cabinet while 70% is recirculated back into the room. This cabinet may be used with etiologic agents treated with minute quantities of toxic chemicals and trace amounts of radionuclides required as an adjunct to microbiological studies if work is done in the directly exhausted portion of the cabinet, or if the chemicals or radionuclides will not interfere with the work when recirculated in the down flow air.
The Type B1 cabinets have a minimum inflow velocity of 100 ft/min
Class II, type B2: this cabinet must be totally exhausted, with100% of the air exhausted through a dedicated duct. This cabinet may be used with etiologic agents treated with toxic chemicals and radionuclides required as an adjunct to microbiological studies.
The Type B1 cabinets have a minimum inflow velocity of 100 ft/min.
The biosafety cabinet class 2are fabricated with inward air flow to protect personnel, HEPA-filtered downward vertical laminar airflow for product protection, and HEPA filtered exhaust air for environmental protection. When properly maintained and operated, they effectively contain and capture microbial contaminants and infectious agents using HEPA/ULPA filters.
Ambient air is pulled through front grille to create inflow, without going into the work surface. Inflow is joined by half of the downflow, to create front air curtain that is fine-tuned to create a large performance envelope. The combined air stream travels through the back air column towards the blower.
Approximately required air in the common plenum is exhausted through the HEPA/ULPA filter to the room. The remaining air is passed through the downflowHEPA/ULPA filter and into the work area as a vertical laminar flow air to create ISO Class 3 work surface and prevents cross contamination.
The biosafety cabinet class II has dual wall construction that surrounds the work zone with negative pressure plenums for maximum safety. Air flow is drawn from the room around the operator into the front grille of the cabinet. Moreover the powder coating finish prevents microbial growth on the exterior and delivers a sleek elegant appearance.
Illumination- Fluorescent light illumination greater than 800 lux on work table along with optimal wattage ultra violet UV light ensure high level of cleanliness in our equipments.
Noise level-The biosafety cabinet class II are designed to ensure minimum possible vibration and noise level.