Several studies have shown that hydrogen peroxide vapor (H₂O₂) can be useful in decontaminating HEPA filters, isolation chambers and centrifuge enclosures.^1-3 However, before hydrogen peroxide can be used reliably in a biological safety cabinet (BSC), it is essential to establish the cycle parameters which allow full decontamination, and which minimize overall cycle time. This paper describes research which established the appropriate physical modifications and decontamination cycle parameters for the Baker Model SG-600, which is a Class II, Type A/B3 biological safety cabinet.