First choose the foam type by the fuel. For hydrocarbon fuels such as petrol, diesel and oil, AFFF forms a thin film on the fuel that stops vapour release, under a foam blanket that cools the fuel and cuts off oxygen: HD Fire offers AFFF 1-C6 at 1%, AFFF 3-C6 and 3F-C6 at 3% and AFFF 6-C6 at 6%, plus the low temperature AFFF 3FZ-C6 for storage and use down to -18°C, and Balaji Fire Safety offers 3% AFFF in 20 litre packs and a 1% AFFF, whose exact product FPS confirms with Balaji before supply. Where water miscible polar solvents such as acetone and IPA are stored, choose an alcohol resistant concentrate: HD Fire AR-AFFF 1X3-C6 is used at 1% on hydrocarbons and 3% on polar solvents, 3X3-C6 at 3% on both, and 3X6-C6 at 3% and 6%.
Then match the percentage and approvals to your system. A concentrate must run through a proportioner, inductor or branch pipe set to the same percentage, and a lower percentage means less concentrate to store for the same amount of foam solution; HD Fire lists most of its concentrates for fresh, sea/salt or hard water. Where a listed system is specified, HD Fire lists UL on AFFF 1-C6, AFFF 3-C6, AFFF 3F-C6, AR-AFFF 3X3-C6 and AR-SFFF F3 3X3, and FM Approved on AFFF 3F-C6 and on HD AR-AFFF 3X3-C6 as part of an FM approved low expansion system. Balaji Fire Safety offers an ISI marked 3% AFFF that it states is tested to IS 4989 and supplies with its ISI licence (CML) number, while its other 3% AFFF listings do not show ISI.
For specialist risks, HD Fire FP 3-C6 and FP 6-C6 fluoroprotein concentrates offer good sealing and burn back resistance, resist fuel pickup and suit sub-surface application, for long pre-burn fires at petroleum tank farms, oil jetties, refineries and offshore oil platforms. FFFP 3/6-C6 adds a fluorinated surfactant to a protein base so it spreads faster on non-polar solvent fires, Hazmat Foam (HF) forms a very stable blanket that holds down hazardous vapours from chemical surfaces, and AR-SFFF F3 3X3 is a fluorine free, PFAS free concentrate for hydrocarbon and polar solvent fires that also suits Class A risks.
For refilling ABC extinguishers, Balaji Fire Safety supplies multi purpose ABC dry powder, mainly monoammonium phosphate (MAP), in 25 kg bags for class A, B and C fires, with most listings showing ISI. Balaji lists the MAP content as 10% or 15%, so compare it with the grade shown on your extinguisher label, as the fire rating depends on the powder; FPS confirms the right powder for your units before refilling.