Biosafety Cabinet 101

In this article we tackle the most common questions we get about biosafety cabinets

  • Biosafety cabinets are specialized lab equipment commonly found in labs across the country. In this article we tackle the most common questions we get about biosafety cabinets. We will cover the following topics in this article:

  • What Is A Biological Safety Cabinet Used For?

  • How To Use A Biological Safety Cabinet

  • How To Use a Biological Safety Cabinet

  • How To Use a Biological Safety Cabinet

  • The Different Biosafety Cabinet Types

  • Biosafety Cabinet vs Fume Hood

What Is A Biological Safety Cabinet Used For?

A biological safety cabinets sole purpose is to protect lab workers and the surrounding environment from potentially harmful biological materials. These cabinets ventilate the air within the workspace and filter that air. This prevents potentially contaminated air from seeping back onto the worker, into the work area or back into the environment. Before the air is ejected into the outside environment or filtered and recirculated, it is run through a HEPA filter. This is to help to pull bacteria and viruses from air protecting the lab environment, work area and user.

How To Use A Biological Safety Cabinet

  • Set up the workspace so that you work from clean to dirty. It is important to work consistently from one direction to the other to help avoid cross contamination.
  • You must work at least 4 inches inside the front grill to ensure vents don’t get blocked and contaminants stay within the cabinet.
  • Be careful not to overcrowd your biological safety cabinet, this can lead to air grills being blocked.
  • It is important to disrupt airflow as little as possible. You can do this by doing slow direct movements when operating in the space and avoiding fast sweeping motions.
  • Reduce foot traffic near the cabinet when in use to prevent airflow issues from occurring.

How To Clean A Biological Safety Cabinet

Once work is complete, you should disinfect and wipe down all reusable items before removing them from the biosafety cabinet. Once items have been removed from the cabinet it is important to disinfect the interior surfaces of the biosafety cabinet with the appropriate disinfectant.

It is important to routinely deep clean your biosafety cabinet. This can be done by using a disinfectant solution. This disinfectant commonly contains Isopropyl alcohol and deionized water but there are many disinfectants on the market. It is important to hit all interior surfaces when cleaning. It is recommended to do this in the following order:

  • Ceiling
  • Front Wall
  • Back Wall
  • Left Wall
  • Right Wall
  • Work Surface

Be sure to get all hard to reach places and use a swab if necessary. If a drain pan is in use it should be emptied into an appropriate container and the drain value should be cleaned as well.

You will then want to clean the exterior of the unit. For this you will commonly use non-sterile isopropyl alcohol and deionized water solution but many disinfectants are on the market. Start at the top and work your way down to the bottom when cleaning the exterior of the unit.

How Often To Certify A Biological Safety Cabinet

Biological safety cabinets should be certified when installed and the certified at least once every year according to OSHA. Annual certifications are occasionally waived on a case by case basis if activities within the cabinet are deemed to be “Low-risk”. It is also important to remember that if a biological safety cabinet is moved for any reason, it is required to be re-certified before put back into operation.

##The Different Biosafety Cabinet Types

There are 3 classes of biosafety cabinets as classified by the US Center for Disease Control and Prevention.

  • Class I cabinets are used for “lower risk” contaminants and do not offer product protection from contamination.
  • Class II cabinets are further divided into four sub types: A1, A2, B1 and B2. With each subtype the minimum inflow velocity differs and the way that air exhausted differs. Class II cabinets offer the product protection that Class I cabinets do not.
  • Class III cabinets are used for “high risk” contaminants and offer the most protection. These cabinets are gas tight and are commonly referred to as glove boxes.

Biosafety Cabinet Vs Fume Hood

Biosafety Cabinets and Fume Hoods may look similar in some instances, however there are some very important distinctions.

A fume hood is designed to remove chemical fumes and aerosols from a work space and protect employees working on them. Biosafety cabinets on the other hand, are designed to provide a clean working environment and protect the employees. So, the primary difference is that a fume hood protects the user and biosafety cabinets protect the user and the materials.

Another common difference is that biosafety cabinets utilize HEPA filtration systems while fume hoods do not. This is due to the nature of the infectious biological agents inside the cabinet.