The following list is a guide to locations where premise isolation may be considered a moderate hazard:
- shopping malls
- multi-unit residential
- office buildings
- pleasure boat marinas
- schools and colleges The following list is a guide to locations where premise isolation may be considered a severe hazard:
- hospital buildings with operating, mortuary or laboratory facilities
- radioactive material processing plants
- petrochemical processing facilities
- premises where inspection is restricted
- sewage treatment plants
- commercial laundries (excluding laundromats)
- plating or chemical plants
- docks and dockside facilities
- food and beverage processing plants
- steam plants
- trackside facilities for trains An assessment of the hazard must be carried out to determine the need, if any, for a backflow prevention device.