In this division:
"environmental emergency" means a foreseeable occurrence that, if it occurred, would be likely to cause—
(a) the entry into the environment of a measure of a pollutant that exceeds the measure authorised by or under this Act; and
(b) as a result of the entry of that excess pollutant, serious or material environmental harm.
"preparation requirements" means a course of action mentioned in section 81 (1) (b).