Biosafety Cabinet: Defined

From the previous blogs, the term biological safety cabinet has been mentioned. But have you asked yourself, what is it? What does it do? Well, in this next blog, we will be discussing about biological safety cabinet and its relevance to biosafety.

What is a biological safety cabinet?

A biological safety cabinet (biosafety cabinet) has been widely used to describe a variety of containment devices equipped with HEPA filter(s), designed to provide personnel, or both personnel and product protection from biohazardous materials. In the European Standard EN 12469, the term used is microbiological safety cabinet.

Example of a Biological Safety Cabinet
Photo credits from: www.escoglobal.com

These terms should only be applied to those devices that meet the requirements of Class I, II or III specifications based on their:

1. Construction. Biological safety cabinets are cabinet-like containment devices with typical parts like HEPA filter, sash, work tray and blower.
2. Airflow velocities. Airflow velocities depend on international standards for biological safety cabinets like NSF/ANSI 49 and EN 12469.The airflow velocity of a typical biosafety cabinet is controlled so as to properly contain infectious microorganisms within the cabinet.
3. Airflow patterns. Airflow patterns vary among the classes of biological safety cabinets, some recirculate air to the cabinet while others totally exhaust air outside.
4. Exhaust systems. Exhaust systems vary among classes of biological safety cabinets, either through hard duct, thimble duct or inside the room.

Biological safety cabinets should be in accordance to international standards. Here are some of the international standards:

• American Standard NSF/ANSI 49
• European Standard EN 12469
• Australian Standard AS 2252
• Japanese Standard JIS K 3800
• Chinese Standard SFDA 440569

NSF/ANSI 49 and EN 12469 have been the most widely used international standards for biological safety cabinets.

What are the Classes of Biological Safety Cabinets?

In general, we have three (3) classes of BSCs – Class I, II and III. They have major similarities and differences which will be discussed on the next blog. Moreover, these different classes of BSCs have different applications too.

What is the relevance of using a Biological Safety Cabinet?

When working with infectious microorganisms, the use of personal protective equipment such as laboratory gowns, gloves and mask is not enough in ensuring the safety of the laboratory personnel.

Personal protective equipment is the least effective control. It is highly recommended to use a combination of controls (practices and techniques, safety equipment and facilities) – biosafety - to ensure the safety of not only the laboratory personnel but also the environment. 

Biological safety cabinets play an important role in an effective biosafety program. It is the primary means of containment when dealing with infectious microorganisms. Depending on the Biosafety Level, the use of the different classes of biosafety cabinets is highly recommended.

However, remember that a biological safety cabinet is only one part of an overall biosafety program. Following safety practices and techniques, wearing personal protective equipment and modifying facilities are still highly recommended.

Sources:

1. Centers for Disease Control and Prevention. Appendix A – Primary Containment for Biohazards: Selection, Installation, and Use of Biological Safety Cabinets. USA. Centers for Disease Control and Prevention. Available from http://passthrough.fw-notify.net/download/462456/http://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdf [Accessed August 24, 2015].
2. ESCO. A Guide to Biosafety & Biological Safety Cabinets. Singapore. Esco Micro Pte. Ltd. Available from: http://www.escoglobal.com/products/download/1334055444.pdf [Accessed August 24, 2015].