Ventilation and drainage.
CFR · 2024-01-01 · US · Title 14
Each compartment containing any part of the powerplant installation must have provision for ventilation and drainage of flammable fluids. The drainage means must be— (a) Effective under conditions expected to prevail when drainage is needed, and (b) Arranged so that no discharged fluid will cause an additional fire hazard.
official document · source cfr-2024 · id 14:§ 27.1187