Sentence 4.2.4.2.(4)

Intent 1:

To limit the probability of the spread of smoke from a fire involving flammable liquids, combustible liquids or unstable liquids to occupied parts of the building, which could lead to harm to persons.

Intent 2:

To override the [implied] permission in Subsection 4.2.9. for fire separations to have openings [protected with closures as per NBC].