All portions of the biosafety cabinet must be accessible for decontamination procedures. Inaccessible areas within the biosafety cabinet may become reservoirs of contamination and hazardous to the certifier of the biosafety cabinet. All external corners and angles subjected to splash and spillage must be sealed as smooth as the surfaces being joined and formed without sharp edges which can cause injury. Uneven edges may cut the user and result in an occupational exposure to the biohazards used within the biosafety cabinet. All joints and seams must be sealed as smooth as the surfaces being joined.
Smooth surfaces facilitate decontamination and minimize the accumulation of dirt or debris.
All biosafety cabinets must be UL listed and NSF listed. All biosafety cabinets should have an audible alarm to indicate when the sash is raised above the manufacturer's specified opening height. The biosafety cabinet function is compromised when the sash is raised over the recommended height since the air intake velocity at the face of the biosafety cabinet will fluctuate. This will also invalidate the NSF listing since the tested height concurs with the manufacturers specifications. HEPA filters shall be tested for leakage of less than 0.01 percent when certified.