An increasing number of Class II BSCS are used in animal studies and a significant number of these applications involve the use of cytotoxic drugs. Use of cytotoxic drugs in Class II BSCs exposes service personnel to permanently-contaminated surfaces. Notwithstanding that the volumes of drugs used in this work are relatively low compared to a hospital pharmacy; the potential exists for cabinet service personnel to be exposed to residue of drug compounds. This suggests the need to review criteria for selection of cabinets to protect all personnel – regardless of whether the application is in a in a research laboratory or a pharmacy.