The right protection starts with the right class
Biosafety cabinet
Before any spec, one decision settles the rest: which class, and which type, does your work actually need? Get the biosafety level right and everything else follows. If you run a lab in India, this page helps you choose the right cabinet.
- NSF/ANSI 49
- HEPA H14 to EN 1822
- BSL-1 to BSL-3
- Engineered and built in-house
FIG. 01Class II biosafety cabinet, front elevation. Room air is drawn in at the work aperture and never blown out of it.
What it is
A biosafety cabinet (BSC), also called a biological safety cabinet, is a ventilated enclosure for working safely with infectious or biohazardous material. A Class II cabinet protects three things at once: the operator, the product and the environment. It does this with a moving shield of HEPA-filtered air.
One limit matters more than it looks. The filters capture airborne particles only, never gases or vapours. So a BSC contains biological aerosols, not solvent fumes.
A cabinet that guards a live culture is not the cabinet that guards you from acid vapour. Neither is the bench that only keeps a sample clean. Which protection you are buying is the whole decision, and the class decides it, covered next.
Three jobs, one box
What a Class II cabinet is actually protecting
Room air is drawn inward at the work opening to protect the operator, HEPA-filtered air falls over the work to keep the sample clean, and everything leaving the cabinet is HEPA filtered again to protect the room.
A fume hood does the first of these and nothing else. A laminar clean bench does the second and nothing else, and it does it by blowing air at you.
How a biosafety cabinet works
A Class II biosafety cabinet, the most-specified class, runs three airstreams at once. Each protects a different party.
Operator protection
Inward air curtain
Room air is drawn in through the front opening at a controlled inflow. The moving air forms a barrier at the sash, so aerosols cannot escape toward the person working there.
Product protection
HEPA downflow
A blower pushes air down through a HEPA filter. A curtain of clean, particle-free air falls vertically over the work surface, keeping the sample safe from room air and from the operator.
Environment protection
HEPA exhaust
Air leaving the cabinet passes through a HEPA filter before it is recirculated or discharged. Viable particles are captured before they can reach the room or the outside during normal operation.
Again, the filters trap particles only. They do nothing to gases or vapours, which is why a biosafety cabinet is not a substitute for a fume hood.
The inward barrier and the downflow are balanced against each other. Too little inflow and aerosols leak out. Too much and the air curtain disturbs the clean downflow over the work. That balance is set at manufacture and proven again at certification, on site.
| Airstream | Protects | Working figure |
|---|---|---|
| Inflow at the front openingRoom air, unfiltered | the operator | around 0.5 m/s (100 fpm) face velocity as general NSF/ANSI 49 practice; the Fabtech design figure is confirmed per model |
| HEPA downflowFiltered, vertical, over the work | the product | in the 0.25 to 0.4 m/s range as general practice |
| HEPA exhaustFiltered before it leaves | the environment | HEPA-filtered before air is recirculated or discharged |
FIG. 02General NSF/ANSI 49 practice. Fabtech design figures are confirmed per model.
The three classes of biosafety cabinet
Biosafety cabinets come in three classes, and they are not tiers of quality: they are different containment designs for different risks. The class is chosen by what you handle and at what biosafety level, not by cost.
Class I
Operator + environment
Open front, room air drawn across the work, HEPA on the exhaust only.
Not the product
Class II
Operator + product + environment
HEPA downflow over the work, inward air curtain at the front, HEPA exhaust.
The workhorse
Class III
Maximum containment
Sealed and held at negative pressure, HEPA supply, double-HEPA exhaust, autoclave pass-through.
Gas-tight glovebox
- Unfiltered room air
- HEPA-filtered air
FIG. 03The three classes in section. Class I leaves the work open to room air. Class II lays a HEPA-filtered curtain over it. Class III seals the operator out of the box entirely and works through gloves.
| Class | ProtectsTHIS PAGE | Containment principle | Typical biosafety use |
|---|---|---|---|
| Class IOpen front | operator and environment, not the product | open front; room air drawn in across the work; HEPA on the exhaust only | BSL-1 to BSL-3 work where the sample need not stay sterile |
| Class IIThe workhorse | operator, product and environment | HEPA-filtered downflow over the work, inward air curtain, HEPA exhaust | BSL-1 to BSL-3, including cell culture and sterile handling |
| Class IIISealed glovebox | operator, product and environment, maximum containment | gas-tight, sealed glovebox at negative pressure; supply and double-HEPA exhaust; autoclave or dunk-tank pass-through | BSL-3 and BSL-4; the most hazardous agents |
FIG. 04Protection direction is what separates the classes, not build quality or price.
The plain rule: protect your sample as well as yourself, Class II. A fully sealed barrier for the most dangerous agents, Class III. Operator and room only, Class I.
Class II is the class most Indian labs specify, and it is the only one of the three that splits further into types. Those types are set out below, because the split is where most specification errors are made.
Which class do you need? Match it to your biosafety level
The cleanest way to choose is to start from your biosafety level (BSL), the risk tier of the organism you handle. This is the standard WHO and CDC mapping, and it is the fastest route to the right cabinet before any quote.
| Your biosafety level | What you typically handle | Cabinet class that fitsTHIS PAGE |
|---|---|---|
| BSL-1Basic teaching and undergraduate labs | agents not known to cause disease in healthy adults | Class I or Class II |
| BSL-2Most clinical and diagnostic work | moderate-hazard agents, common in clinical, diagnostic and teaching labs | Class I or Class II, with Class II most common |
| BSL-3Containment suite, dedicated exhaust | serious or lethal agents transmissible by inhalation, for example M. tuberculosis | Class II with the right facility controls, or Class III |
| BSL-4Maximum containment | dangerous agents with no vaccine or therapy | Class III, or Class II with a positive-pressure suit |
FIG. 05Standard WHO and CDC mapping. The facility controls around the cabinet are set separately.
The biosafety level sets the cabinet class. The facility around it then has to match: the room pressure cascade, the HEPA-filtered exhaust, the airlocks.
Fabtech designs the two together, the cabinet and the room around it, as one system. We have built BSL-3 containment labs where both were designed and delivered together, not bought separately and hoped to agree on test day. If you are standing up a BSL-2 or BSL-3 lab, start from this row and we will size the cabinet and the suite together.
For the biology alongside the room design, see our work in biotech cleanrooms .
Class II types: A1, A2, B1 and B2
Most labs that ask for a biosafety cabinet need a Class II, and within Class II there are four types. They differ by how much air is recirculated versus exhausted, and by whether the cabinet is hard-ducted.
Everything in that sentence happens at one point inside the machine. Air leaving the work zone is pushed up the rear plenum by the blower and then divides: part of it goes back down through the supply HEPA as fresh downflow, and part of it goes out through the exhaust HEPA. The size of that division is the type.
- 01
The operator is protected by the inflow
Room air is pulled in through the front aperture and straight down into the front grille, so nothing raised on the work surface can travel back out at the person.
If it fails If the inflow drops, aerosols leak out of the aperture into the room and into the operator's breathing zone.
- 02
The product is protected by the downflow
HEPA-filtered air falls vertically over the work tray as a clean curtain, so the sample sees filtered air and never the room, the bench or the operator's hands on the way in.
If it fails If the downflow is disturbed or the filter is loaded, room air and skin flora reach the culture and the work is contaminated.
- 03
The environment is protected by the exhaust
Every cubic metre that leaves the cabinet passes a HEPA filter first, whether it is discharged to the room or ducted away through a canopy connection.
If it fails If the exhaust filter leaks or bypasses, viable particles are released into the laboratory or into the building's exhaust.
The plenum split
70 back, 30 out. That ratio is the type.
Recirculated air is filtered again on the way down. Exhausted air is filtered on the way out. A Type A2 divides them at roughly 70 to 30. A Type B2 does not divide them at all: everything goes out.
- Not yet filtered
- HEPA filtered
- Air route
FIG. 06Class II Type A2 in section, running. Three airstreams at three different velocities, all of them perpetual, dividing at the plenum. Roughly 70 percent of the air is recirculated back down through the supply HEPA and roughly 30 percent leaves through the exhaust HEPA. Move that division to 100 percent exhaust and the same cabinet becomes a Type B2.
- 01
The operator is protected by the inflow
Room air is pulled in through the front aperture and straight down into the front grille, so nothing raised on the work surface can travel back out at the person.
If it fails If the inflow drops, aerosols leak out of the aperture into the room and into the operator's breathing zone.
- 02
The product is protected by the downflow
HEPA-filtered air falls vertically over the work tray as a clean curtain, so the sample sees filtered air and never the room, the bench or the operator's hands on the way in.
If it fails If the downflow is disturbed or the filter is loaded, room air and skin flora reach the culture and the work is contaminated.
- 03
The environment is protected by the exhaust
Every cubic metre that leaves the cabinet passes a HEPA filter first, whether it is discharged to the room or ducted away through a canopy connection.
If it fails If the exhaust filter leaks or bypasses, viable particles are released into the laboratory or into the building's exhaust.
The plenum split
70 back, 30 out. That ratio is the type.
Recirculated air is filtered again on the way down. Exhausted air is filtered on the way out. A Type A2 divides them at roughly 70 to 30. A Type B2 does not divide them at all: everything goes out.
| Class II type | Recirculated / exhaustedTHIS PAGE | Ducting | What it suits |
|---|---|---|---|
| Type A2The default | around 70 percent recirculated, 30 percent exhausted | to the room, or ducted out through a canopy (thimble) connection | general microbiology and cell culture; the most common choice by a wide margin |
| Type A1Legacy arrangement | recirculated, at a lower inflow than an A2 | to the room, or canopy connected | an older, lower-inflow arrangement now less specified for new labs |
| Type B1Partial exhaust | a larger share of air exhausted than an A2 | hard-ducted | limited use of volatile chemistry in trace amounts alongside the biology |
| Type B2Total exhaust | 100 percent total exhaust, nothing recirculated | hard-ducted | trace volatile chemicals or radionuclides used alongside the biology |
FIG. 07As general NSF/ANSI 49 practice. Which types Fabtech catalogues is confirmed per model.
The practical fork
Type A2 covers the large majority of installations in Indian labs. The practical fork is ducting: an A2 can be run to the room or taken outside through a canopy connection, while a B1 or a B2 must be hard-ducted, and that decision belongs to the building, not to the cabinet.
Engineered and built in-house in India
This is the part that sets Fabtech apart: we design and build our biosafety cabinets in-house, in India. The cabinet is engineered to the room it will stand in. The airflow is set and proven by the same team that designs the containment suite around it. One accountable partner stands behind both.
If you are searching for a biosafety cabinet manufacturer in India, this is the difference you are buying: an engineering team that builds the cabinet, not just a supplier. We engineer and build these cabinets ourselves, and the team behind them has delivered 2,000+ controlled environments across every industry that needs controlled air since 2004, including BSL-3 containment labs.
What you buy is a cabinet specified to your biosafety level, built to standard, installed, and certified on site.
The filters themselves, their grades and how they are tested, are set out on HEPA filtration .
The build essentials
- Cabinet standard
- designed and certified to NSF/ANSI 49
- Filtration
- HEPA H14 on the downflow and on the exhaust, rated to EN 1822 for particulate capture
- Work zone
- stainless steel 304 or 316, for cleanability and chemical resistance
- Monitoring
- instrumentation that shows the operator the cabinet is within its safe airflow range
Build specifics are confirmed per model before quotation.
- Controlled environments delivered
- 2,000+
- Building controlled environments since
- 2004
- Sector that needs controlled air
- Any
- Highest containment level delivered
- BSL-3
The cabinet is half the answer
The biosafety level sets the class. The facility around it has to match.
A Class II cabinet in a room with no pressure cascade, no dedicated exhaust route and no airlock is a safety device asked to do a building's job. In a BSL-3 suite the cabinet, the cascade, the HEPA-filtered exhaust and the airlocks are one containment system, and they are commissioned as one.
- Highest routine containment most Indian labs build
- BSL-3
- The class most Indian labs specify
- Class II
- Cabinet and suite, designed together
- One system
Standards a biosafety cabinet is built and judged against
A biosafety cabinet earns trust on one question: does it actually contain, and keep containing? That is what its standards measure. They are the cabinet's own set, not the standards used for a fume hood.
The cabinet itself answers to NSF/ANSI 49, at build and again in the field. Its filters carry their own rating, and the room around it is classified separately under ISO 14644. Where the cabinet serves sterile or regulated production, the wider facility is also built to withstand inspection under EU-GMP Annex 1 and its Indian counterparts. Regulators inspect the facility; they do not certify a cabinet.
- NSF/ANSI 49Class II cabinet design, construction and, critically, field certification. The cabinet is certified at installation and re-certified on a schedule, typically annually. This is the standard that decides whether a cabinet is a safety device or a cupboard with a fan.
- EN 1822 (HEPA H13 / H14)The classification of the high-efficiency filters that keep the downflow and the exhaust clean of particulates. H13 captures at least 99.95 percent and H14 at least 99.995 percent of particles at the most penetrating particle size (MPPS), which is the hardest size for a filter to catch.
- ISO 14644-1 / -2 / -3The classified suite the cabinet lives in, from ISO Class 5 to ISO Class 8. The room is designed and validated to its own standard, not the cabinet's, and a certified cabinet in an unclassified room is still an unclassified room.
- EU-GMP Annex 1, Schedule M, WHO-GMPThe GMP context where the cabinet serves sterile or regulated production, including EU-GMP Grade A and Grade B zones. The facility is built to withstand inspection under these frameworks. Inspectors inspect the facility; they do not certify a cabinet.
There is no single Indian Standard for a biosafety cabinet
There is no single Indian Standard that is the biosafety cabinet code. Any specific IS or BIS reference is confirmed per project.
We anchor the cabinet on NSF/ANSI 49, and the room on its own cleanroom and GMP context, never a phantom code. Where a tender does cite an Indian Standard, it is read alongside NSF/ANSI 49 rather than in place of it.
How the room itself is classified, and what each ISO class means in particle terms, is set out on ISO classification .
Biosafety cabinet vs fume hood vs laminar clean bench
These three enclosures look similar and are constantly confused, but they protect opposite things. Choosing the wrong one is not a shopping error; it is a safety error.
Biosafety cabinet
Operator, product and environment
Biohazards: live cultures, infectious agents
Fume hood
The operator only
Toxic, corrosive and flammable chemical fumes
Laminar clean bench
The product only
Particle-sensitive work. Never a biohazard
- Unfiltered air
- HEPA-filtered air
FIG. 08Protection direction, drawn three ways. The biosafety cabinet pulls air in, filters a curtain down over the work and filters everything on the way out. The fume hood only pulls in. The clean bench only blows out, and it blows across the work and into the operator.
| Enclosure | ProtectsTHIS PAGE | Airflow | Right for | Never use for |
|---|---|---|---|---|
| Biosafety cabinetThis page | operator, product and environment | HEPA downflow over the work, inward air curtain, HEPA exhaust | biohazards: live cultures, infectious agents | significant volatile or flammable chemicals; most classes are not rated for them |
| Fume hood | the operator only | room air pulled in and exhausted away | toxic, corrosive and flammable chemical fumes | keeping a sample sterile, which it does not do; biohazards |
| Laminar clean bench | the product or sample only | clean HEPA air blown out, toward the operator | particle-sensitive work: sterile filling, electronics | any biohazard. It blows the agent straight at you |
FIG. 09Protection direction, not appearance, is what separates these three enclosures.
Read that last row carefully: a laminar-flow clean bench is not a biosafety cabinet. It protects the product and gives the operator no protection at all. It must never be used for infectious material.
If the hazard is chemical rather than biological, the right enclosure is a fume hood . If the purchase document calls it a fume cabinet, a fume cupboard or a fume chamber, those are names for the same machine . If you only need to keep a sample clean, and there is no hazard to the operator, that is a laminar air flow bench .
The one exception on chemicals is a Class II Type B2 cabinet. It is used for trace volatile chemistry alongside the biology, never as a replacement for a proper fume hood.
Where we have delivered containment
We have engineered and delivered BSL-3 containment laboratories at PGICH Noida and at ASMC Shahjahanpur. That is the highest routine containment level most Indian labs build. In both, the biosafety cabinet, the room pressure cascade, the HEPA-filtered exhaust and the airlocks were designed and validated as one system.
That is what a cabinet buyer gets from us: a team that has taken a containment suite all the way through design, build and on-site validation.
Containment record
FABCLEAN / CONTAINMENT RECORD
- 01
PGICH Noida
BSL-3 containment laboratory.
- 02
ASMC Shahjahanpur
BSL-3 containment laboratory.
Project scope and specifications are available on request.
- HEPA grade on downflow and exhaust
- H14
- H14 capture at MPPS, to EN 1822
- 99.995%
- Typical inflow face velocity
- 0.5 m/s
- Type A2 recirculated to exhausted
- 70 / 30
- Typical NSF/ANSI 49 re-certification
- Annual
Certification, validation and maintenance
A biosafety cabinet is a safety device, so its performance is proven on a schedule, not assumed. The proof runs on these tracks, from the build line to the annual re-certification.
- 01Build line
Balanced and set at manufacture
The inward barrier and the downflow are balanced against each other before the cabinet ships. Too little inflow and aerosols leak out. Too much and the air curtain disturbs the clean downflow over the work.
- 02At installation
Certified on site to NSF/ANSI 49
Inflow and downflow velocity, the airflow smoke pattern and filter integrity are measured in place and recorded against the standard. A cabinet is not certified in a factory; it is certified where it stands.
- 03Part of certification
HEPA integrity test, PAO or DOP
The downflow and exhaust filters are challenged with an aerosol and scanned across the face and the seal, proving they are leak-free with no bypass around the frame.
- 04Regulated production
Qualified with the room: DQ, IQ, OQ, PQ
Design Qualification checks the plan. Installation Qualification checks the build. Operational Qualification proves the cabinet runs to spec. Performance Qualification proves it keeps performing in use.
- 05Typically annually
Re-certified on a schedule
Certification is repeated on a schedule, and again after the cabinet is moved, after a filter change and after any work that could disturb the airflow balance.
- 06Equipment only
Maintained under AMC
Filter change-out, airflow re-certification and monitor checks, carried out on the cabinet as equipment. Facility maintenance stays with the client after handover.
FIG. 10From the build line to the annual re-certification. A biosafety cabinet is certified where it stands, not where it was made.
On the certificate
What a certification actually measures
Four measurements decide whether a cabinet is still a safety device. All four are taken on site, in the room the cabinet works in, with the room's own air handling running.
- Inflow velocity
- the speed of the air curtain at the front aperture, which is what keeps aerosols inside
- Downflow velocity
- the speed and uniformity of the clean curtain falling over the work surface
- Smoke pattern
- a visualised airflow test proving the curtain and the barrier are where the design says they are
- Filter integrity
- an aerosol challenge and scan of the downflow and exhaust HEPA filters, for leaks and bypass
An annual maintenance contract covers the cabinet as equipment: filter change-out, airflow re-certification and monitor checks. AMC applies to the equipment only. The project ends in a handover, and facility maintenance is managed by the client.
For validation across a whole controlled environment, not just the cabinet, see cleanroom validation .
Three ways out of this page
Which enclosure you need is decided by what you are protecting. Pick the row that matches your hazard.
If the hazard is chemical
HEPA captures particles, not gases or vapours. A chemical hazard needs an enclosure built to move vapour away from you and out of the building.
If you only need a clean sample
A laminar clean bench protects the product and nothing else. It is the right answer for particle-sensitive work with no hazard to the operator, and the wrong answer for anything biological.
If you are building the room around it
A cabinet is one component of a containment suite. The pressure cascade, the filtration, the transfer route and the validation file are the rest of it.
Biosafety cabinets, common questions
A biosafety cabinet is used for working safely with infectious or biohazardous material, such as live cultures and clinical samples. A Class II cabinet protects the operator, the product and the environment at the same time. HEPA-filtered air contains aerosols rather than letting them be inhaled or released.
The four biosafety levels, BSL-1 to BSL-4, rate the hazard of the agents in use. BSL-1 covers agents not known to cause disease in healthy adults, BSL-2 moderate-hazard agents, BSL-3 serious agents spread by inhalation, and BSL-4 agents with no vaccine or treatment. The level sets your cabinet class and the facility controls around it.
There are three classes. Class I protects the operator and the environment but not the product. Class II adds product protection with a HEPA-filtered downflow, an inward air curtain and filtered exhaust, and is the default for cell culture. Class III is a gas-tight glovebox for maximum containment.
A Class III biosafety cabinet is a gas-tight, sealed glovebox held at negative pressure and operated through attached gloves. It has a HEPA-filtered supply, a double-HEPA exhaust and a double-door autoclave or dunk-tank pass-through. It is used for BSL-3 and BSL-4 work.
A Class I cabinet protects the operator and the environment but does nothing to keep the sample clean, because room air is drawn across the work. A Class II cabinet adds product protection: a curtain of HEPA-filtered air falls over the work surface, so the sample sees filtered air rather than room air.
Type A2 is the most common: about 70 percent of air is recirculated, 30 percent exhausted, suiting general microbiology and cell culture. Type B2 is 100 percent total exhaust and hard-ducted. It is chosen only when trace volatile chemicals or radionuclides are used alongside the biology. Most labs need an A2.
No, and confusing them is dangerous. A laminar clean bench protects only the product and blows air toward the operator, so it must never be used for biohazards. A biosafety cabinet protects the operator, the product and the environment.
Generally no. A biosafety cabinet uses HEPA filtration, which captures particles only and does nothing for gases or vapours. It is not rated for significant volatile or flammable chemicals; those need a fume hood. The only exception is a Class II Type B2, at 100 percent exhaust, for trace volatile chemistry.
Class II cabinets are designed and certified to NSF/ANSI 49, which governs both the build and the field test. The HEPA filters carry their own rating under EN 1822. The room around the cabinet is classified separately to ISO 14644. In regulated production, the wider facility must also stand up to EU-GMP inspection.
A biosafety cabinet is certified to NSF/ANSI 49 at installation and re-certified on a schedule, typically annually. It is also re-certified after the cabinet is moved, after a filter change, and after any work that could disturb the balance between the inflow and the downflow.
A biosafety cabinet is quoted per requirement, not sold at one list price. Cost is driven by class and type, size, filtration grade, stainless grade, monitoring, installation and on-site certification. Send us your biosafety level and the agents you handle and we will scope it.
Tell us what you handle
Send us your biosafety level and the agents you handle. Our engineers will size both the cabinet and the room around it in one specification, rather than quoting a box and leaving the suite to someone else.