are maintained between the outer shell of any cupola or other melting unit and any wall, equipment or obstruction.
Firing and fuel supply controls, for each melting unit, are clear and accessible from an aisle or location that is remote from the melter.
Aisles or passageways adjacent to melting units are not less than 1.2 meters (4 ft) wide.
Working space at melting units is not less than 1.8 meters (6 ft), when measured horizontally from a pouring spout or furnace shell (additional space may be required, based on the plant risk assessment and sections 4.16(h) and 4.16(i) of this audit).