(b) Rules of the commission shall require that each specific model of diesel-powered equipment shall be approved before it is taken underground. The rules shall provide that in addition to requiring that each diesel engine have an assigned MSHA approval number securely attached to the engine with the information required by 30 C.F.R. §§ 7.90 and 7.105, the approval plate shall also specify the minimum ventilating air quantity required by the commission for the specific piece of diesel-powered equipment. The rules shall provide that the minimum ventilating air quantity be determined based on the amount of air necessary at all times to maintain the exhaust emissions at levels not exceeding the exposure limits established by the commission pursuant to section four hundred six of this article.
(c) Rules of the commission shall require that the minimum quantities of air in any split where any individual unit of diesel-powered equipment is being operated shall be at least that specified on the approval plate for that equipment. Air quantity measurements to determine compliance with this requirement shall bemade at the individual unit of diesel-powered equipment.
(d) Rules of the commission shall establish the minimum quantities of air required in any split when multiple units are operated. Air quantity measurements to determine compliance with this requirement shall be made at the most downwind unit of diesel-powered equipment that is being operated in that air split.
(e) Rules of the commission shall provide that minimum quantities of air in any split where any diesel-powered equipment is operated shall not be less than the minimum air quantities established pursuant to subsections (a) and (b) of this section and shall be specified in the mine diesel ventilation plan.