Airborne Infectious Isolation Room Exhaust ducts, and the maintenance thereof.

[FBW]

Does anyone know if there are any regulated policies / procedures for working inside these exhaust ducts ( working on sensors, dampers, inspections, etc)? I've asked the question at my site and no one seems to know the answer. Lots of opinions, but no reference to any regulations/codes/standards/ etc. I cant believe this exhaust doesn't fall into some sort of definite category, with accompanying standards.

I should mention I'm in Canada, but from my experience we usually follow ASHRAE or other international standards.

Thanks.

 

[GMcD]

Here in BC, the design of the isolation room systems require protection of the maintenance staff, which falls under the WorkSafe BC acts, and there is no really "specific" guideline other that what you can also find in the Excited States OSHA and NIOSH publications. Things like bag-in-bag-out HEPA filters, UV lamps and other sterilization methods can be used. The general practice in the local Hospitals I've done Isolation rooms for have a local UV lamp set at the room exhaust point to minimize contamination upstream in the exhaust duct, and then we use UV lamps and HEPA filters at the main exhaust ducts before the exhaust fans to make sure the main isolation room exhaust fans are in a more or less "sterile" state for maintenance access. Each Hospital will have a Health and Safety Office and their own specific Work Practices Guidelines. I wrote a Standard Operating Procedures document for the BC CDC for their maintenance staff to use back in my mis-spent youth, and each major Hospital should have a similar document for infection control protocols.