Revisions were made to reflect reference to ISO 6944 and provide clarification on the duct type to be Duct A. Furthermore, the use of the fan for developing 300 pa underpressure and leakage measurements in ISO 6944 is not required.

This Standard addresses requirements for both external fire engulfment and internal grease fire.

This Standard specifies a method of test and criteria for the determination of the fire resistance of grease ducts under standardized fire conditions. The requirements are intended to evaluate the ability of the grease duct to resist the spread of fire.

This Standard also covers requirements to evaluate the ability of the duct to protect adjacent combustibles from igniting in the event of an internal grease duct fire.

The grease ducts covered by these requirements are intended to be installed in accordance with the requirements in the National Building Code of Canada as pertaining to ventilation of commercial cooking processes.

This Standard does not include requirements for combustibility, the surface flammability and the smoke generation potential of the coverings or insulating materials used to protect the grease duct.