Assertion: ignition | /r/AtLocation | volumetric ratio of hydrogen
Facets:
value: in chemical properties
type: OTHER
value: to air
type: OTHER
value: due to the oxygen
type: CAUSE
value: in the air
type: LOCATION
Source sentences:
text: Hydrogen possesses the NFPA 704's highest rating of 4 on the flammability scale because it is flammable when mixed even in small amounts with ordinary air; ignition can occur at a volumetric ratio of hydrogen to air as low as 4% due to the oxygen in the air and the simplicity and chemical properties of the reaction.