Near Miss

An incident that is prevented at the last moment or is narrowly avoided.
Any unplanned event which, but for the mitigation effects of safety systems or procedures, could have caused harm to health, the environment or property, or could have involved a loss of containment possibly giving rise to adverse effects involving hazardous substances.
Reference: OECD Environment, Health and Safety Publications Series on Chemical Accidents No. 10, Annex 1, 2nd Ed., 2003.