Our partners over at Formaspace have taken an in-depth look at the key principles of laboratory furniture design in order to help those in the medical and healthcare industries understand how different types of equipment perform different sets of operations in the lab.
Final specifications for each type of equipment should be made in partnership with your lab’s Chief Safety Officer (CSO), casework manufacturer, and/or technical specialists who are familiar with the equipment manufacturer’s products. The governing regulations covering exposures to chemicals or biohazards from agencies such as OSHA (or Cal OSHA in California), the FDA, NIOSH, and the NSF should be considered as well.
Understanding The Full Spectrum Of Laboratory Cabinetry
You often hear these three terms used somewhat interchangeably: laminar flow cabinets, biosafety cabinets (BSCs), and fume hoods.
The confusion is understandable. First, medical lab furniture can all look somewhat similar to the untrained eye. Second, they all rely on fast-moving air to get the job done. The difference lies in the details.
While many lab cabinets look the same, their operation (as well as the objectives they are trying to achieve) can be quite different. For this reason, it can be dangerous to assume that, for example, a laminar flow cabinet can protect you from toxic fumes or biohazards. By design, it cannot.
Let’s start by taking a look at the role and function of laminar flow cabinets.
Laminar Flow Cabinets: Protecting The Product From Contamination
From a human safety standpoint, laminar flow cabinets are the simplest category. Why? They are specially designed to protect the product from contamination. This usually means human contamination, such as dust particles spread from clothing, dander from skin, stray human hairs, etc. Laminar flow cabinets DO NOT protect the human lab worker. Thus, their use in any lab setting is limited to working only with non-toxic materials. You’ll often find laminar flow cabinets located inside cleanroom environments, for example, in semiconductor manufacturing labs or in some USP 797 Non-Hazardous Drug Compounding operations.
How do Laminar Airflow Cabinets Work?
Typically, air is drawn into the cabinet using a fan, and then it passes through a HEPA filter to remove any particles. The particle-free air is blown across the work zone in a straight line—i.e. in a laminar air stream—at a rate of about 80-100 fpm.
The direction of the airflow can come from above, blowing directly down onto the product. This type is called a vertical laminar flow cabinet. The laminar airflow can also originate in the back of the unit blowing across the product into the face of the operator. This type is called a horizontal laminar flow cabinet.
Vertical flow designs are more suitable for manipulating large objects in the work zone, as the airflow does not get blocked as easily by the object. However, horizontal flow cabinets work well for small items, such as semiconductors, which can be positioned at the back of the work zone closest to the continuous flow of clean air.
BSL Level 4 Glovebox Biosafety Cabinet (Class III BSC)
Next, we’ll contrast the simplicity of the laminar flow cabinet with one of the most highly regulated units: a Glovebox Biosafety Cabinet (BSC) used in a Level 4 Biosafety Laboratory (BSL-4). This lab cabinet is built to handle extremely dangerous biohazards such as the ebola virus.
Unlike laminar flow cabinets, whose primary function is to maintain a sterile environment for handling products or sample specimens, the primary function of any class of biosafety cabinets is to protect the human lab workers from exposure to biohazards, including bacteria, viruses, fungus, etc.
You probably already have a good image in your mind of the glovebox biosafety cabinet design. A worker typically dons a white containment suit and enters a special BSL-4 cleanroom to work at a sealed, glass-fronted cabinet fitted with two arm holes mounted with internal rubber gloves.
The lab operator slides his hands into the gloves, allowing him or her to manipulate dangerous products or samples within the cabinet without having any direct contact with the air contained inside. The air entering the cabinet is HEPA-filtered on the way in. The contaminated exhaust air is HEPA-filtered twice on the way out then hard ducted directly through the roof to vent into the outdoors. (In some cases, an incinerator is used instead of the second HEPA exhaust filter.)
When to Use Fume Hood Cabinets
If you’re ever working with hazardous chemicals, you’ll want to think twice about the type of cabinets you’re using.
We should warn you: never use a Laminar Flow Cabinet to work with toxic chemicals under any circumstances. The Fume Hood’s primary function is to protect the user from chemical vapors by drawing in air from the front of the cabinet (away from the user’s face) and then either immediately exhausting it outside or thoroughly filtering it through one of the chemical filters before recycling the air into the room.
Most fume hood cabinets feature a window sash that opens in the front, which gives them a similar appearance to many of the laminar flow cabinets (except for the distinctive glovebox BSCs).
Which Fume Hood Type Should You Choose, Ducted or Ductless?
Ducted fume hoods have more capacity to deal with larger volumes or complex combinations of toxic chemical fumes. On the other hand, ducted fume hoods require a bigger investment for installation. Energy usage with ducted units is significantly higher, too.
Adhering to proper safety practices is critical for fume hood operation in general, whether you are using a ducted or ductless system. It’s very important to conduct regular safety inspections with certified gas detection systems to ensure that the filters are working properly in accordance with applicable regulations, such as OSHA guidelines for exposure to chemical hazards and toxic substances.
Take measures to prevent explosions seriously and keep safety equipment—such as fire extinguishers, eye wash stations, emergency showers, and chemical vapor test equipment—close at hand. Never use the fume hood as a storage area for chemicals.
For more information on laboratory cabinets, come see the brand-new bkm lab showroom and book a tour here. You can also take a look at some of our products from 300+ manufacturers for any of your technology laboratory casework or furniture needs.
A version of this article was originally published on Formaspace.