For the purpose of these Guidelines the following definitions
apply:
1.2.1
Foam (fire fighting): an aggregate
of air filled bubbles formed from an aqueous solution of a suitable
foam concentrate.
1.2.2
Foam solution: a solution of
foam concentrate and waters.
1.2.3
Foam concentrate: the liquid
which, when mixed with water in the appropriate concentration, gives
a foam solution.
1.2.4
Expansion ratio: the ratio
of the volume of foam to the volume of foam solution from which it
was made.
1.2.5
Spreading coefficient: a measurement
of the ability of one liquid to spontaneously spread across another.
1.2.6
25% (50%) drainage time: the
time for 25% (50%) of the liquid content of a foam to drain out.
1.2.7
Gentle application: application
of foam to the surface of a liquid fuel via a backboard, tank wall
or other surface.
1.2.8
Sediment: insoluble particles
in the foam concentrate.