The regulator may conduct an inquiry under this division if a notification under section 536 (Operators of certain facilities must notify regulator) or section 537 (Notification—proposed facilities) discloses, or if for some other reason the regulator reasonably suspects, that—
(a) the quantity of Schedule 15 chemicals present or likely to be present at a facility (or proposed facility) exceeds 10% of their threshold quantity but does not exceed their threshold quantity; or
(b) the operator of the facility (or proposed facility) may not be a suitable person to operate the facility (or proposed facility).