Form and physical state matter: liquids spread and gases move faster and reach higher airborne concentrations, and vapours denser than air flow along floors to ignition sources in adjacent areas. Higher temperature usually lowers the lower explosive limit and raises vapour pressure, and pressure increases release rates and can destabilise chemicals. Confinement in tanks, ducts, silos or rooms makes explosions more violent. Oxidisers can react violently with organic materials, hydrocarbon solvents and other carbon-based chemicals, and the risk persists under an inert gas because they supply their own oxygen. Incompatible chemicals can react exothermically and rupture containers. Combustible dust (paper, grain, organic compounds, metals) explodes when accumulated dust is disturbed by wind, sweeping or compressed air and meets an ignition source, with a secondary explosion possible from dust shaken loose, and smaller particles raise the risk (metal filings or dust versus an ingot, aerosolised liquid versus bulk). Dust atmospheres are classified as hazardous areas under AS/NZS standards.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.