Protective measures in a laboratory environment are dependent on what is being handled and the potential dangers involved. Testing tissues or materials that pose no danger to the user does not require the level of protection required when working with the bio-contaminants that could cause sickness or death. Both types of testing may require some level of air purification. Knowing which is essential not only in providing safety measures but also in determining the cost of equipment for the lab is extremely important.

The laboratory’s work area typically has lab fume hoods that remove contaminants; however, the level of protection may need to be increased to keep staff, the environment, and samples protected. Laminar flow cabinets and biological safety cabinets provide this protection.

Laminar Flow Cabinets

Fume hoods draw the air in the room which leaves the samples in the work area open to contamination. Laminar flow cabinets protect the samples using either horizontal or vertical airflow. Laminar flow cabinets are typically used in manufacturing, medical and pharmaceutical, and scientific research laboratories. The users in these labs are not normally working with dangerous samples and do not need the added layer of protection provided by biological cabinets.

Laminar flow cabinets are either horizontal or vertical flow cabinets, each offering benefits depending on the intended use.

Horizontal flow hoods have nominal wind effects on the work surface. This makes these hoods best suited for use in situations where the tools and equipment being used in testing would not get in the way of the airflow and possibly impede contamination control. Testing that requires a higher level of protection from contaminants should opt for horizontal flow.

Testing and other applications that use larger equipment in the work area are best suited for vertical flow cabinets. Gravity works with the vertical flow of air to push the contaminants away from the workspace. Air from these hoods is circulated back into the environment as is and is not purified or treated in any way.

Biological Safety Cabinets

Biological safety cabinets protect the user, environment, and the tested material from contamination during use. These cabinets are available with various levels of protection. Some can protect only the user, while others can protect the environment, the user, and the material being tested all at once. Some have open work areas, and others are completely enclosed with glove boxes for working.

  • Class I boxes offer user protection
  • Class II protects the user, environment, and specimen and has an open access area for work
  • Class III are glove boxes that protect the user, environment, and specimen in a closed work area
  • Class III boxes are essential when working with toxins, aerosols, and any biosafety level 4 material

Unlike laminar flow cabinets that push air away from the materials and possibly toward the operator, the biological safety cabinets have an airflow across the work surface that is unidirectional. When personal safety and the environment are a concern, these boxes have a negative pressure inside that prevents air contamination outside the work area.

The air inside biological safety cabinets is circulated through a HEPA filter before being recirculated and exhausted to the room. This ensures added protection to the user and the environment from potentially harmful contaminants.

Which is Better?

Both laminar flow hoods and biological safety cabinets are good at providing protection. The gauge for which one is better depends on why the protection is needed and what needs to be protected.

Laboratories that do not work with hazardous materials and only need to ensure that the samples they work with are not contaminated may be best suited with a less expensive laminar flow hood.

On the other hand, laboratories that work with potentially dangerous biotoxins or pollutants that could harm the user or the environment are better suited to the biological safety cabinet. Further, if the agent being tested needs added protection from being contaminated by the environment, this box is the best option.

If cost is the main consideration and there is no chance of harm to the user or environment, a laminar airflow cabinet may be the best option. But, if there is any chance that the user or environment could be harmed, the biological safety box is the best option.

Laboratories should also consider future testing when making investments in safety equipment. If the lab could possibly need the safety afforded by a biological safety box in the future, it may be worth the initial investment rather than having to purchase additional equipment later.


Laboratories that test materials and specimens use different types of protection compartments based on the type of materials tested. Laminar flow cabinets and biological safety boxes are the major choices, and each offers protection at varying levels.

Laminar flow cabinets offer protection for the samples being tested and not the user or the environment. The level of protection offered depends on the flow of air, either vertical or horizontal. These cabinets may be used with air filters that protect the air being circulated back into the environment. The work inside the cabinet is protected; however, the user and the environment are not protected from the material.

Biological safety cabinets have added protection that prevents the user, the environment, and the samples from being contaminated. The airflow configuration in these boxes is vertical only. These boxes must comply with regulations regarding the inflow, downflow, and cross-contamination processes that provide the protection.

Biological safety cabinets come in various classes, depending on how much protection is needed. This includes enclosed boxes that prevent the user from direct physical contact with the samples that are being tested.

Laboratories have to consider all aspects of the testing being performed now and in the future when making decisions on safety cabinets. Employee and environmental safety should be taken into account, as well as the validity of testing if the materials are exposed to contaminants in the air.

At Laboratory Design and Supply we offer a wide range of laminar flow cabinets and biological safety boxes that can be customized for your lab needs. If you need guidance and costing make sure you reach out to our specialist team today for more information.