FIRE PROTECTION AND FIRE ALARM ENGINEERS MSF House, Charlwood Rd, Lowfield Heath, CRAWLEY, West
Sussex, RH11 OPT.
Tel 01293 543838. Fax 01293 537590. email:
sales@msf-fire.co.uk
The Extinguisher
AFFF (Aqueous Film Forming Foam) is a synthetic foam which modifies its molecular
structure when added to water. This liquid provides a medium which will not only cool a
fire but will form a fine film to prevent oxygen supporting the flames. On Class B fires
the film forming process will also prevent re-ignition occurring.
AFFF (Aqueous Film Forming Foam) as used in fire extinguishers is not recommended for
fires involving pure alcohol or alcohol based solvents in depth.
Fire Rating †
The fire rating of an extinguisher is intended to provide an indication as to the
effectiveness of the fire extinguisher and not a direct indication of the size of any
actual fire which an inexperienced operator could extinguish. Anyone who may have to use
an extinguisher should be trained in its use and receive basic instruction in safe fire
fighting.
Electrical Risks
Stored pressure Foam Spray AFFF extinguishers feature a purpose designed nozzle enabling
them to pass the 35kV test to Clause 4 of BS EN3 - 2 and be specified for Class A and B
risks in the proximity of live electrical equipment in accordance with 855306: Part 3:
1985.
NOTE: Should not be used to cover direct electrical risks.
