What makes this powder suitable for Class A, B, and C fires?

It contains Monoammonium Phosphate (MAP). It smothers Class B/C fires and melts to form a barrier on Class A fuels, inhibiting re-ignition.

What is the minimum MAP content required by IS 14609?

The standard specifies a minimum of 50% MAP content by mass (Table 1).

What is the maximum allowed moisture content?

The maximum moisture content is 0.25% by mass (Table 1), to prevent the powder from caking inside the extinguisher.

Is this powder toxic?

It is generally considered non-toxic, but inhalation of the fine powder during discharge should be avoided as it can be a respiratory irritant.

IS 14609

: 1999

Dry Chemical Powder for Fighting A, B, C, Class Fires -Specification

CurrentEssentialSpecificationFire Safety · Fire Fighting

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This standard specifies the requirements for dry chemical powder, based on monoammonium phosphate, used for extinguishing Class A, B, and C fires. It covers the material's chemical composition, physical properties like particle size and moisture content, performance in fire tests, packing, and marking.

Dry Chemical Powder for Fighting A, B, C, Class Fires -Specification

Quick Reference Values

Minimum Monoammonium Phosphate Content50 percent by mass

Maximum Moisture Content0.25 percent by mass

Minimum Particle Retention on 150 micron IS Sieve0 percent

Minimum Particle Passing 45 micron IS Sieve35 percent by mass

Minimum Apparent Density (Tamped)0.85 g/ml

Practical Notes

The primary active ingredient is Monoammonium Phosphate (MAP), which smothers the fire and melts to coat Class A materials, preventing re-ignition.

Ensure the powder is stored in sealed containers as moisture absorption is the primary cause of caking and extinguisher failure.

This powder is mildly corrosive, especially in the presence of moisture. Post-discharge cleanup is important to prevent damage to metals and electronics.