Congratulations, you have money allocated for a new hood or biosafety cabinet! But now comes the hard part: which important piece of protective equipment do you choose? Both serve a similar purpose — a form of containment — but there are some distinct differences you should consider before placing your equipment order.
First, let’s define the two.
- Biological safety cabinets (pictured above and also known as BSCs) provide personnel, product and environmental protection from hazardous particulates that require Biosafety Level 1, 2 or 3 containment. The Centers for Disease Control and Prevention (CDC) defines biological safety cabinets (BSCs) as “the primary means of containment developed for working safely with infectious microorganisms.”
- Laminar flow clean benches (pictured above), also sometimes known as laminar flow hoods, protect products and samples for a variety of life science, industrial lab and process applications. But it’s important to note that they don’t provide protection for lab workers or the environment. Laminar flow hoods provide a sterile environment for the sample, but you aren’t protected from airflow, which is why working with harmful or toxic materials or chemicals with this type of equipment is strongly discouraged.
Types of Biological Safety Cabinets
There are three types of biological safety cabinets, which vary in levels of protection. Your choice of cabinet will depend on what level of protection you need for your workers, your space and your samples.
- Class I provides protection for you and the environment, but not your samples.
- Class II, which is the most common, provides protection for you and those in your lab, samples and products, and the environment.
- Class III provides the most protection since the enclosure is gas-tight. These models include the same state-of-the-art features as the Class II cabinets, in addition to a primary physical barrier that offers protection between the lab worker and the biological agent.
Here’s a helpful chart, courtesy of BSC manufacturer The Baker Company:
| Classification | Biosafety Level | Application |
| Class I | 1, 2, 3 | Low-to-moderate-risk biological agents |
| Class II | 1, 2, 3 | Low-to-moderate-risk biological agents |
| Class III | 4 | High-risk biological agents |
Biosafety levels are “used to identify the protective measures needed in a laboratory setting to protect workers, the environment, and the public,” according to the U.S. Department of Health and Human Services. You can find the complete breakdown of biosafety levels here.
Pros & Cons for Biological Safety Cabinets
Pros
As we’ve mentioned, biological safety cabinets come in three levels, so there’s definitely not a “one-size-fit-all” approach. Your choice of cabinet depends on what level of protection you need for you, your lab workers, your space and the samples.
Biosafety cabinets also meet or exceed National Sanitation Foundation (NSF) 49, which is an international standard for this type of protective lab equipment. According to Baker, NSF tests biological safety cabinets to make sure they meet the minimum standards for cabinet classifications, which are defined as NSF/ANSI 49 – 2008, BioSafety Cabinetry: Design, Construction, Performance and Field Certification.
All BSCs come with a HEPA filtration, an audible alarm and a flashing LED screen to indicate when the sliding viewscreen is in an unsafe position. Some models that require connection to the HVAC system feature an audible/visual airflow alarm and automatic shutoff system called the Airflow Monitor (AFM), which warns when the exhaust airflow decreases.
Some models even save you up to 70% annually in operating costs due to a large reduction in energy consumption and heat yields.
Cons
A BSC is more expensive than a laminar flow clean bench, but it does provide more protection. BSCs are also large, so you need to make sure you have the floor space and ceiling height to accommodate this type of lab equipment.
Types of Laminar Flow Clean Benches
The two categories of laminar flow hoods refer to the direction of airflow within the hood.
Horizontal laminar flow clean benches are designed for a variety of industry applications involving low-risk agents, including:
- Sterile product preparation
- Sterile drug compounding
- IV admixture preparation
- Plant cell culture
- Media preparation
- Pharmaceutical procedures
Vertical laminar flow clean benches provide controlled airflow in one direction over the entire work surface. They are ideal for when product protection and particulate control are required. They are also designed for the same variety of industry applications as horizontal laminar flow hoods.
Pros & Cons for Laminar Flow Hoods
Pros
Laminar flow hoods come in two models, vertical and horizontal, depending on the desired direction of your airflow. If space is tight in your lab, consider a vertical model, which isn’t as deep. Space-saving models are great for limited areas such as IV and nursing stations, satellite pharmacies and intensive care units.
All laminar hood models also comply with standards from the International Organization for Standardization (ISO), which provides classifications for cleanrooms and the air inside them.
Cons
While a laminar flow hood is an important piece of equipment that protects your samples, it doesn’t protect you and your colleagues in the lab. Also, even though you might only need the product protection that a laminar flow hood provides, your research/work may change in the future, which means you may need the kind of protection a BSC provides.
When Should You Choose a Biological Safety Cabinet?
You should choose this type of lab equipment when you’re looking for the utmost protection, especially from hazardous, toxic or infectious droplets, aerosols and materials. A BSC will protect you, your lab and your samples depending on the model’s classification.
When Should You Choose a Laminar Flow Hood?
Since a laminar hood blows air toward you, it’s important that you don’t use this equipment for any type of toxic, pathogenic or hazardous material.
D.A.I. Scientific Is Your Trusted Choice for Lab Equipment
Biological safety cabinets and laminar flow hoods are both important pieces of lab equipment, but there are some major differences — and the last thing you want to do is order the wrong type or model. We know the process of selecting new equipment can be overwhelming, but don’t worry — we’re here to help!
The experts at D.A.I. Scientific are familiar with every type of analytical laboratory in the pharmaceutical, educational, clinical and biotech industries. What sets us apart is our commitment to understanding and supporting our products. Do you have questions about temperature monitoring, equipment capacity, voltage or dimensions? Our highly qualified staff has the answers and will find the right equipment for you.
We have what you need to get started, and we’d be more than happy to answer your questions about which biological safety cabinet or laminar hood is the best fit for your space. Contact us today to get started!
FAQs
Q: When should you choose a biological safety cabinet?
A: You should opt for a BSC when you’re looking for the utmost protection, especially from hazardous, toxic or infectious droplets, aerosols and materials.
Q: What’s the difference between a horizontal and vertical laminar flow clean bench?
A: The difference is the direction of airflow within the hood.
Q: What’s the difference between a fume hood and a biosafety cabinet?
A: A BSC provides protection from hazardous materials with HEPA filters that treat and exhaust air. Fume hoods provide personnel protection by keeping harmful vapors from the breathing zone of the users, but your samples are in unfiltered air, so there is no product protection.
Q: When is a vertical laminar flow cabinet the best choice?
A: They are ideal for when you are working with non-hazardous samples that require product protection with clean HEPA-filtered air.
Q: Why would I vent a Class II A2 BSC?
A: If your samples have an order to them, a non-ducted BSC would have those orders go back into the room. Also, a vented BSC does give you another level of protection. If somehow your exhaust HEPA filter became damaged, the potential contaminated exhausted air is not going back to the lab.
Q: Why would I choose a Class II B2 BSC instead of a vented Class II A2 BSC?
A: The A2 cabinet recirculates 70% of the air within the cabinet and exhausts 30%. If your work generates vapors, these vapors will get built up in a recirculating BSC. The B2 BSC is 100% exhaust, so there is no buildup of vapors.
Q: Can my workers be exposed by the UV light within a BSC?
A: No, most modern day BSC manufacturers have built-in safety interlocks that turn off a UV light if the sash is opened.
