3.1.2 Adequate ventilation is to be provided for all areas and enclosed
compartments associated with the oil storage production and process plant. The
capacities of the ventilation systems are to comply, where applicable, with the
requirements of Pt 7, Ch 2, 6 Ventilation, or to an acceptable Code or Standard
adapted to suit the marine environment and taking into account any additional
requirements which may be necessary during start-up of the plant.
3.1.3 Ventilation in the vicinity of mud tanks is to be specially considered to
ensure adequate dilution of any dangerous gases.
3.1.4 For units using oil-based mud, the tanks are to be provided with special
ventilation arrangements, and for open systems, the maximum oil density in the air
above the tanks is not to exceed 5 mg/m3. Ventilation of the enclosed
spaces with open active mud tanks or pits is to be arranged for at least 30 air
changes per hour for personnel comfort.