What base chemicals are permitted by IS 4308 for dry chemical powder?

The powder must be based on either sodium bicarbonate or potassium bicarbonate.

What is the maximum allowable moisture content?

The maximum allowable moisture content is 0.25 percent by mass (Table 1).

Can this powder be used on electrical fires?

Yes, dry chemical powder meeting this standard is non-conductive and can be used on Class C and electrical fires.

IS 4308

: 2003

Specification for Dry Chemical Powder for Fighting B and C Class Fires

CurrentFrequently UsedSpecificationFire Safety · Fire Fighting

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This standard specifies the physical, chemical, and performance requirements for dry chemical powder (based on sodium bicarbonate or potassium bicarbonate) used as an extinguishing agent for Class B and Class C fires.

Specification for Dry Chemical Powder for Fighting B and C Class Fires

Quick Reference Values

Maximum Moisture Content0.25 % by mass

Apparent Density0.75 to 1.15 g/ml

Water Repellency Test Moisture AbsorptionMaximum 1.5 % by mass

Temperature Stability Range-20 °C to +55 °C

Practical Notes

Do not mix this powder with Monoammonium Phosphate (ABC powder) as it can cause a chemical reaction leading to pressure buildup and caking.

Powder must be stored in a dry environment and hermetically sealed to prevent moisture absorption, which degrades its free-flowing characteristics.

This specification covers B and C class fires only; it is not suitable for deep-seated Class A fires or Class D combustible metal fires.