major accident(An unexpected occurrence, failure or loss beyond normal or specified levels with the potential for harming human life, property or the environment)
major risk(The high probability that a given hazard or situation will yield a significant amount of lives lost, persons injured, damage to property , disruption of economic activity or harm to the environment; or any product of the probability of occurrence and the expected magnitude of damage beyond a maximum acceptable level)
major risk installation(Installations whose functioning involves the possibility of major hazards such as chemical plants, nuclear, coal and oil power production plants, etc.)