Type

Limitations

Rating

• Conductor of electricity
• Protection required below 40 degrees F and above 120 degrees F.
• Not effective on water-soluble flammable liquids (polar solvents) such as alcohol (unless otherwise stated on nameplate.)
• Not effective on pressurized flammable liquid/gas fires (AFFF only)
• Not effective on cooking grease fires

A/B

• Limited effectiveness under windy conditions
• Severely reduced effectiveness at sub-zero temperatures (F)
• Not effective on pressurized flammable liquid/gas fires
• Limited effective discharge range
• Not effective on cooking grease fires in depth reaching auto-ignition temperature (500-550 degrees F)

B/C

• Obscures visibility in confined spaces
• Cleanup needed on delicate electronic equipment
• Limited effectiveness on Class B obstruction fires

B/C

• Obscures visibility in confined spaces
• Corrodes uncoated metal surfaces (at above normal humidity and/or temperatures above 250 degrees F)
• Damages electronic equipment
• Limited penetrating ability on deep-seated Class A fires
• Marginal effectiveness on cooking oil grease in depth (flashback may occur)
• Limited effectiveness on Class B obstruction fires.

ABC

• Relatively ineffective on pressurized flammable liquid/gas fires.
• Restriction of agent concentration in enclosed areas
• May cause corrosion of metals exposed to moisture

B/C or
A/B/C

• Conductor of electricity
• Use on flammable liquids will spread fire
• Water type needs protection from freezing
• Loaded stream corrodes many metals or surfaces

A