Laminar Flow Cabinets

Laminar flow cabinets, commonly referred to as tissue culture hoods or laminar flow hoods, are self-contained enclosures designed to protect sensitive materials from exposure to particulate or microbial contamination. It's a relatively simple device that utilises HEPA filtration to produce a stream of laminar flow air over the internal worksurface, thereby shielding workspace samples from contamination.

The first concept of "laminar flow air" originated during the late 1950s. Willis Whitfield developed the first laminar flow cleanroom in 1959 during his tenure at Sandia National Laboratories. Essentially, you can think of a laminar flow cabinet as a small-scale cleanroom with an ISO rating to match the level of cleanliness the workspace provides. While some laminar flow cabinets create ISO 4 cleanroom conditions, others create ISO 5. The level of cleanliness you need depends on the application or process the product is required for.

In theory, these devices also function similarly to a biosafety cabinet. However, unlike a biosafety cabinet, laminar flow cabinets do not protect the operator, only the sample. For example, if you have an application involving a benign, non-toxic material, a laminar flow cabinet would be a suitable device. On the other hand, if the material is potentially hazardous or zoonotic in nature, a class I, II or III biosafety cabinet would need to be used.

Laminar flow cabinets are available in two configurations, vertical and horizontal. Typically, the products also feature a germicidal UV-C lamp to cleanse the worksurface between tests, reducing the likelihood of cross-contamination.

A laminar flow cabinet works by streaming particle-free air over the unit's interior workbench at a smooth, uniform velocity to prevent sample contamination. A fan draws air from the intake grille through a high-efficiency particulate air (HEPA) filter, which removes 99.97% of airborne particles greater than 0.3 microns in size. The filtered air is then blown in a unidirectional pattern (laminar flow) over the work sample to remove contaminants and ensure a sterile working environment.

The products are available in two configurations, horizontal and vertical. The type of unit you choose depends on the nature of the application. A horizontal laminar flow cabinet directs filtered air from the back of the unit towards the operator. On the other hand, a vertical laminar flow cabinet directs filtered air from the top of the unit onto the work surface. Although both designs maintain the integrity of the sterile environment, vertical laminar flow cabinets are often preferred thanks to increased operator comfort and equipment storage space. For information on the differences between these two units, please visit: "Horizontal Vs Vertical Laminar Flow Cabinets".

To ensure your cabinet functions correctly, follow the recommended operator guidelines. When switching the unit on, double-check your airflows and move the sash to the correct working height. Next, minimise movement to prevent airflow disruption and avoid clutter inside the workspace.

Laminar flow cabinets can use HEPA and ULPA filters. However, the type of filter you choose depends on the process taking place inside your cabinet. While ULPA filters remove 99.9995% of particles 0.12 microns in diameter or larger, HEPA filters are more cost-effective, capturing 99.97% of particles 0.3 microns in diameter or larger.

Typically, you would only choose ULPA filters when working with fine particles or to increase the level of cleanliness. For example, ULPA filters can produce ISO 3 cleanroom conditions, while HEPA filters produce ISO 5.

For more information on the benefits of HEPA filters, please visit "What Are HEPA Filters and How Do they Work?".

No. Laminar flow cabinets are designed for benign, non-toxic materials. If you work with harmful biological substances, a Class I, II, or III biosafety cabinet is required to ensure sample and operator protection. If you work with corrosive acidic compounds such as hydrochloric, sulfuric, or nitric acid, a fume cupboard is necessary to capture and exhaust harmful vapours. Using a laminar flow cabinet for hazardous substances would expose the operator and the environment to significant risks.

Laminar flow cabinets specialise in creating ISO cleanroom conditions suitable for medical device assembly, manufacturing, packaging and pharmaceutical production. More specialised applications include optical lens assembly, semiconductor work, data recovery, and the preparation of sterile tissue cultures. These are applications where product sterility and particulate control are critical.

In short, choosing the correct cabinet depends on the materials you’re working with and the type of protection required. Laminar flow cabinets are ideal for clean, sterile operations involving non-hazardous materials. For hazardous biological work, a biosafety cabinet is required. When working with chemical fumes or corrosive vapours, a properly ventilated fume cupboard is the safe and appropriate choice.

Always follow your risk assessment and safety guidelines to select the right equipment for your needs. Alternatively, you can contact our team for more information or read "What Are Laminar Flow Cabinets Most Commonly Used For".

The time required to install a laminar flow cabinet varies depending on the unit's size and specifications. To unpack, position and level a floor-standing benchtop cabinet, a few hours should be sufficient. However, in our experience, site conditions are a crucial factor.

You should ensure the area is clear of equipment before commencing the installation process to minimise downtime. If the unit needs to be integrated with external laboratory systems, this could add another hour or two, depending on the complexity of the project.

Next, you should consider the commissioning and certification of the unit. Before use, the cabinet must be tested to ensure it meets ISO standards, which includes checking HEPA filter integrity and airflow velocity. This process can take a few hours and must be performed by a qualified engineer.

Altogether, for a straightforward installation in a ready-to-use lab, you can expect the entire process — from delivery to certification — to take about half a day.

A laminar flow cabinet will typically cost between £4,000 and £6,000, depending on the size and specification of the unit. The specification includes bespoke modifications such as multiple-piece work surfaces, height-adjustable stands, materials and electrical sockets.

Your laminar flow cabinet provider should include a listed breakdown of costs in the quotation process. At TION, we list these modifications as "Optional Extras", appearing separate from the standard base product.

If costs are a deciding factor in your quotation, you can edit the specification or change the model of your product. For example, we have two baseline models, Pro laminar flow cabinets and Essential laminar flow cabinets.

The difference between these two ranges lies in the building materials. The Pro model is built from medical-grade welded polypropylene while the Essential range is built from mild steel.

While PCR cabinets use UV to sterilise the environment, LAF cabinets use an air-cleaning filtration system (HEPA or ULPA). The technology removes any particles on the work surface, ensuring a contamination-free environment. There are two separate models available:

• Horizontal Laminar Flow Hood – Air is projected horizontally across the work area directly out of the front of the cabinet.
• Vertical Laminar Flow Hood – Air is projected downward, and then across the work surface and out of the unit.

Remember, laminar flow cabinets are produced to protect materials inside the workspace. They do not protect laboratory technicians and are not suitable for working with biohazards. To do this, you would need a class II biosafety cabinet.