When does my biosafety cabinet need to be certified?

Class I and II biosafety cabinets should be tested and certified at the time of installation and at least annually thereafter. In addition, whenever HEPA/ULPA filters are changed, maintenance repairs are made to internal parts, or a cabinet is relocated. More frequent field recertification should be considered for particularly hazardous or critical applications or workloads.

USP 797 requires testing on a semi-annual basis.