A laboratory is not a uniform surface
Benches, seals, biological safety cabinets, filters, ductwork, instruments and heat-sensitive equipment have different contamination risks and treatment constraints. Airflows, inaccessible spaces and internal geometries make broad assumptions unsafe. A risk assessment must distinguish equipment to be retained, subjected to dedicated treatment or removed before the room strategy is finalized.
Cabinets and filters require separate assessment
A biosafety cabinet contains much more than a work surface. Plenums, internal compartments, seals and filters present specific access and containment issues. Decontamination before filter service, relocation or disposal must be performed by qualified personnel following a validated plan. Room-wide airborne surface disinfection alone does not establish successful prion treatment inside the cabinet or through filter media.
Sequence and traceability
A defensible plan documents inventory, risk classification, containment boundaries, approved procedures, exposure controls and waste routes. It must also assess non-biological risks such as refrigeration fluids, electricity and maintenance work. Cleaning, equipment removal and fixed-surface treatment should be coordinated to prevent shadowing and recontamination. Records should specify responsibilities and the outcome for each item.
Release requires appropriate evidence
ATP measurements, chemical indicators and bacterial biological indicators answer different questions; none independently proves prion inactivation. Test methods and acceptance decisions must match the risk. Final documentation should identify treated and excluded areas, deviations and outstanding uncertainties. Personnel protection takes precedence over minimizing intervention time.