(1)
The ventilation system for a power-ventilated enclosure referred to in Article 6.3.4.2A. shall
(a)
conform to NFPA 91, “Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Particulate Solids,”
(b)
provide continuous exhaust ventilation at an air velocity sufficient to prevent the accumulation of combustible or reactive deposits in the power-ventilated enclosure and its exhaust duct system,
(c)
confine dangerous goods vapours and particles to the area where they are generated and exhaust them to the outdoors,
(d)
not return the exhausted air to the building, and
(e)
be provided with well identified control switches that are
(i)
located outside the power-ventilated enclosure, and
(ii)
readily accessible in case of an emergency.