IS 4861:1984 is the Indian Standard (BIS) for dry powder for fighting fires in burning metals. 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
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Moisture Content (max) | 0.25% by mass | 0.25% by mass | EN 615:2009 |
| Fire Performance Test | Extinguish fire of 2 kg magnesium turnings in a 50x50x10 cm steel tray. | Varies by rating. E.g., a 4-D rating test uses ~2.2 kg (5 lbs) of magnesium in a 30"x30" pan. | UL 711 |
| Apparent (Bulk) Density | 1.0 ± 0.1 g/ml (for TEC powder). Fixed value. | Manufacturer's nominal declared value ± 7.5%. Not a fixed value. | EN 615:2009 |
| Particle Size Distribution | ≥90% of mass shall be between 45 µm and 150 µm. | Specified as cumulative oversize on different sieves (e.g., <35% on 125µm, <90% on 40µm). | EN 615:2009 |
| Hygroscopicity Test | Static test: 48 hrs at 40°C & 80% RH. Moisture gain must be <0.5%. | Dynamic test: Involves cycles of humidification and heating, followed by a qualitative check for lumps and flowability. | EN 615:2009 |
| Heat Resistance (Thermal Stability) | Heat at 60°C for 24 hours. Mass loss should be <0.5%. | Heat at 60°C for 24 hours. No visible evidence of reaction, decomposition or caking (qualitative). | EN 615:2009 |