No source of ignition may be present inside any hazardous area, determined under AS/NZS 60079.10.1, while goods are loaded or discharged. For goods of class, division or subsidiary hazard 2.1, 3 or 4, the vehicle's engine stays off during discharge unless it drives the pump or compressor (brief running to clear hoses is allowed), and stays off during loading unless the vehicle is a vacuum tanker; the engine and any auxiliary combustion engine are also off while Division 2.1 hose connections are coupled or uncoupled.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.