CAP168 (Feb 2001):
"The operational objective of the RFFS should be to achieve a response of 2 minutes,
not exceeding 3 minutes in circumstances of optimum visibility and surface conditions"
"Response time is considered to be the time between the initial call to the RFFS and the time the first responsing vehicle(s) are in position and
producing foam at 50% of the discharge rate specified" and "Any other vehicles required to deliver the amounts specified........should arrive no later than 1 minute after the first responding vehicle".
CAP168 (pdf)