Clean Air Systems
No. 4, Senthil Nagar, 100 Feet Road
Chennai - 600 094, Tamil Nadu, India
Phone: +(91)-(44)-23621476, 23622772
Mobile: 0091 9841074504, 0091 9551119111
Laminar Airflow
Bio-Hazard Safety Cabinet
Air Shower Entry System
Clean Room Pass Box
Powder Containment Booths
Sterile Garment Cabinet
Softwall Clean Room
Modular Clean Room
Positive Pressure Module
Clean Air Fan Filter Units
Laboratory Fume Exhaust Hoods
Laboratory Furniture
Air Curtains
Clean Room Validation
Metal Doors
Cleanair™ Biological Safety Cabinets, enclosed containers and other engineering controls are designed to remove hazardous biological materials. The biological safety cabinet is the principal device used to provide containment of infectious splashes or aerosols generated by many microbiological procedures. The equipment is widely applicable and is used in biomedicine, microbiology and gene recombination. Our Biological Safety Cabinets have the following technical specification:
Laboratory Biosafety Manual.
Second Edition (revised). Interim guidelines. World Health Organization. p32.
Class Inflow Velocity
Recirculation of Air (%) Exhaust
Air (%)
Control Plenum surrounded By Exhaust Alternatives Biosafety
Class I US: 038
EN: 0.70
0 100 Outside Air

Inside room /
Hard duct

1, 2 & 3
Class II
US: 038
EN: 0.40
70 30 Outside Air Inside room /
Hard duct
1, 2 & 3
Class II
US: 050
EN: 0.40
70 30 Negative Plenum Inside room /
Hard duct
1, 2 & 3
Class II
US: 050
EN: 0.40
30 70 Negative Plenum Hard Duct Only 1, 2 & 3
Class II
US: 050
0 100 Negative Plenum Hard Duct Only 1, 2 & 3
Class III Closed:*
0 100 Negative Plenum Inside Room/Hard Duct 1, 2, 3 & 4
* Pressure differential between chamber and environment
Bio Safety Cabinets Class I
Class I BIOSAFETY is designed for operator and environment protection from hazardous materials and substances for operator's health. The operation is based on the forced removal of hazardous substances from the working zone through the air up-flow, with high-effective air filtration and exhausting the air into the environment. Due to the unidirectional laminar air flow, there is no risk of their cross-contamination when there are more than 2 agents working on the equipment.
Bio Safety Cabinet Class II
Cleanair™ Class II Biosafety Cabinet Type A1 & A2 are designed for the security and protection of operator’s product and environment from pathogenic agents and microorganisms transmitted in respiratory way and also for creation of a bacterial dust free air environment. It has a common plenum from which 30% of air is exhausted, and 70% re-circulated to the work area as part of the downflow. Type A cabinets drain out air directly back to the laboratory, and they may contain positive pressure contaminated plenums. When toxic chemicals must be employed as an adjunct to microbiological processes, these cabinets should not be used. Exhaust HEPA filtration only.

Removes airborne aerosols including biohazards, and not chemical fumes.

The Class II Type A1 consists of the positively-pressurized contaminated plenum bordering the ambient environment, and therefore is less safer than the Class II Type A2 that has a negative pressure surrounding the positively pressurized contaminated plenum. In any unlikely event of a leakage on the positive plenum, the leaking aerosol will be pulled by the negative pressure back to the positive plenum, which prevents it from leaking out. On the grounds of safety, the Type A1 design is now considered obsolete. In the A2 cabinet, approximately 70% of air from the positive plenum is re-circulated as downflow.

Cleanair™ Class II Type B1 Biological Safety Cabinets
The Class II Type B1 biological safety cabinet has a common plenum from which 70% of air is exhausted, and 30% re-circulated to the work area as the downflow.

Type B1 cabinets also have a dedicated exhaust feature that eliminates re-circulation when work is performed towards the back within the interior of the cabinet. Toxic chemicals employed as an adjunct to microbiological processes should only be employed if they do not interfere with work when re-circulated in the downflow.

Cleanair™ Class II Type B2 Biological Safety Cabinets
In the case of Cleanair™ Class II Type B2 cabinet all inflow and downflow air is exhausted after HEPA filtration to the external environment without recirculation within the cabinet. This means that Type B2 cabinets are apt for working with toxic chemicals employed as an adjunct to microbiological processes under all conditions since no re-circulation occurs. In theory, Type B2 cabinets may be measured to be the safest of all Class II biological safety cabinets since the total exhaust feature acts as a fail-safe in the event that the downflow and / or exhaust HEPA filtration systems cease to function normally. However, Class II Type B2 cabinets, in practice, are difficult to install, balance and maintain.
Bio Safety Cabinet Class III
The Class III biological safety cabinet provides an absolute level of safety, which cannot be attained with Class I and Class II cabinets. All Class III cabinets are usually of welded metal construction and are designed to be gas tight. Work is performed through glove ports in the front of the cabinet. During routine operation, negative pressure relative to the ambient environment is maintained within the cabinet. This provides an additional fail-safe mechanism in case physical containment is compromised. On all Class III cabinets, a supply of HEPA filtered air provides product protection and prevents cross contamination of samples. Generally the exhaust air is HEPA filtered and incinerated. Alternatively, double HEPA filtration with two filters in series may be utilized.

Materials are transferred into the cabinet using a pass-through unit installed at the side of the work area. Class III cabinets usually exhaust air back to the laboratory; however, air may also be exhausted via a dedicated ductwork system to the external environment. When a dedicated ductwork system is employed, they are also suitable for work employing toxic chemicals as an adjunct to microbiological processes. All Class III biological safety cabinets are suitable for work with microbiological agents assigned to biosafety levels 1, 2, 3 and 4. They are frequently specified for work involving the most lethal biological hazards.
Dimensional chart for Bio Safety Cabinets
Model No Working Area Size  In Feet Overall Equipment
Size in MM
Top Cabinet
Size in MM
Support Stand Size in MM
  (W x D x H) (W x D x H) (W x D x H) (W x D x H)
CBS 0900  3' x 2' x 2' 1000 x 800 x 2000 1000 x 800 x 1400 1000 x 800 x 600
CBS 1200  4' x 2' x 2' 1300 x 800 x 2000 1300 x 800 x 1400 980 x 850 x 760
CBS 1800  6' x 2' x 2' 1900 x 800 x 2000 1280 x 850 x 1000 1280 x 850 x 760
Home   l   About Us   l   Products   l   Recommended Practices   l   Feedback   l   FAQ   l   Sitemap   l   Contact Us © Clean Air Systems 2010
design: mayuri infomedia