This standard specifies the physical, chemical, and fire performance requirements for dry powder extinguishing agents used specifically for fighting Class D fires involving combustible metals such as magnesium, aluminium, zinc, sodium, and potassium.
Specification for dry powder for fighting fires in burning metals
Quick Reference Values
Target fire classClass D (combustible metals)
Maximum moisture content0.25 percent by mass
Extinguishing mechanismOxygen exclusion via crust formation/smothering
ToxicityNon-toxic
Practical Notes
Never use water, foam, or standard ABC/BC dry powders on combustible metal fires, as they can cause violent or explosive reactions.
The powder must be protected from moisture ingress during storage to prevent caking and ensure flowability.
Application of Class D powder must be done gently to build up a smothering crust without scattering burning metal particles.