Balancing effectiveness, safety, and operating costs
Emerging concerns about laboratory safety, space utilization, and costs have caused a rethinking of what Class 2 BSCs are designed to do and how labs utilize them. Much of this reflection compares how cabinets perform in real life versus their optimized capabilities—standard GAP analysis.
Type 2 BSC design and specifications are governed by NSF/ANSI Standard 49, which was promulgated during the 1970s at the request of regulatory bodies such as the Centers for Disease Control (CDC), National Institutes of Health (NIH), and the National Cancer Institute (NCI). Under Standard 49, NSF (formerly the National Sanitation Foundation) certifies the design, construction, and performance of biosafety cabinets to NSF/ANSI Standard 49 and runs the Biosafety Cabinet Field Certifier Accreditation Program.
All type 2 BSCs provide approximately the same level of biological safety, says Brian Garrett, LEED green associate at Labconco (Kansas City, MO). “The differences lie in their abilities to manage various levels of hazardous or nuisance chemicals, odors, and radionuclides.”
B2 cabinets in particular are totally exhausted, so their entire workspace is suitable for hazardous materials. Yet type A2 BSCs are the most popular—used in 90 percent of installations, according to Garrett—because they provide the best balance between safety, energy efficiency, and ease of installation.
“There’s a gap, particularly in hazardous chemical safety,” Garrett adds. “You don’t want to use A2 for hazards because all the air is recirculated. But on the flip side, A2 cabinets are the easiest to install because they can be tied in with fume hoods, other biosafety cabinets, or even general exhaust. Because B1 and B2 models require dedicated exhaust, they are much more difficult to install.”
This conundrum—balancing effectiveness and safety against ease of installation—is something Labconco is working on. “It’s making us consider whether there may be another way to view safety and installation and provide harmony across those features.”
Smart motor technology
Ergonomics and operating costs—particularly energy savings—are the two leading trends in biosafety cabinets, says Brian Raymond, sales manager at Microzone (Ottawa, ON).
Depending on how they are vented and/or filtered, biosafety cabinets consume energy directly (through the motor) and indirectly (when conditioned air is vented to the environment).
Standard BSCs use alternating current (AC) motors drawing approximately 12 amperes. Leading manufacturers have replaced AC motors with ECM (electronically commutated motor) designs that run on direct current voltage converted from standard AC power.
The inherent efficiency of ECMs provides energy savings of 50 percent or more, while their rugged design increases the motor’s life span by a factor of three. Lower energy consumption also reduces heat loss to the lab environment, which improves user comfort.
ECM is a “smart” motor technology that controls airflow as needed. Much like fume hoods that sense usage or a room’s occupation, ECMs can turn down during off hours. And when desired, they can be programmed to maintain a constant airflow regardless of the HEPA filter load. “The motors communicate with controllers through a microprocessor,” Raymond tells Lab Manager. “If a sash is raised or lowered, airflow changes accordingly.”
Energy savings and service life are good enough reasons to purchase an ECM-based biosafety cabinet, especially for large research centers with a lot of cabinets. In addition, many vendors claim that ECMs are quieter, more ergonomic, and more reliable.
Regardless, this design has become the de facto standard.
For additional resources on biosafety cabinets, including useful articles and a list of manufacturers, visit www.labmanager.com/biosafety-cabinets