Specification for dry powder for fighting fires in burning metals

IS 4861 - Scope: Key Specifications & Requirements

Scope Summary:

• Applies to dry powder with specific particle size distribution.
• Ensures compliance with test/analysis results rounded per IS:2-1960.
• Governs use of Standard Mark under BIS Act, 1986.

Particle Size Distribution (Clause 2.2)

• Test sample: 100 g dry powder.
• Sieving duration: 30 min (hand), 110 min (machine).
• Follow IS:1607-1977 for test sieving method.

Rounding Off (Clause 0.5)

• Final test/analysis values rounded as per IS:2-1960.
• Retain same significant figures as specified values in the standard.

Additional Notes

• Standard Mark use is regulated by BIS Act, 1986.
• Revision based on Defence Institute of Fire Research studies (since 1968).

flowchart LR
    A[Dry Powder] --> B{Particle Size Distribution}
    B -->|100% passes| C[120 µm Sieve]
    B -->|≥ 90% passes| D[75 µm Sieve]
    B -->|≤ 10% passes| E[38 µm Sieve]
    F[Test/Analysis] --> G[Rounding per IS:2-1960]
    H[Standard Mark] --> I[BIS Act, 1986]

This concise scope ensures powder quality and compliance with BIS standards.

IS 4861: Requirements for Dry Powder in Metal Fire Fighting

Key Specifications (Clause 2.2 - Particle Size Distribution)

• 100% passes through 120 µm IS Sieve
• ≥ 90% passes through 75 µm IS Sieve
• ≤ 10% passes through 38 µm IS Sieve

Test Procedure

• Use 100 g of powder sample.
• Follow IS:1607-1977 for sieving.
• Sieving duration:
  • 30 min for hand sieving
  • 110 min for machine sieving

Rounding Off (Clause 0.5)

• Final test or calculated values must be rounded per IS:2-1960.
• Retain the same number of significant places as specified in the standard.

Summary Table: Particle Size Distribution

flowchart LR
    A[Dry Powder Sample (100g)] --> B{Sieving Method}
    B -->|Hand| C[Sieving for 30 min]
    B -->|Machine| D[Sieving for 110 min]
    C & D --> E[Measure % Passing through sieves]
    E --> F[Check % passing]
    F -->|120 µm| G[100% required]
    F -->|75 µm| H[≥ 90% required]
    F -->|38 µm| I[≤ 10% allowed]

This ensures powder fineness suitable for effective metal fire suppression per IS 4861.

IS 4861: Apparent Density of Powder

Key Specification (Clause 2.1)

• Apparent Density Range: 0.75 g/ml to 1.18 g/ml

Test Method (Clause 2.1.1)

1. Take 100 g of dry powder.
2. Place in a 250-ml glass-stoppered graduated cylinder (IS: 878-1975).
3. Rotate cylinder slowly end over end for 10 cycles.
4. Set upright, let powder settle for 60 seconds.
5. Gently level the surface.
6. Note volume of powder (V ml).

Formula for Apparent Density:

[ \text{Apparent Density (g/ml)} = \frac{100 \text{ g}}{V \text{ ml}} ]

Summary Table:

This method ensures consistent measurement of powder bulk density for quality control.

IS 4861: Free Flowing Characteristics of Dry Powder

Key Specifications (Clause 2.5)

• Use 100 g dry powder in a glass funnel (diameter 7.5 cm), outlet plugged.
• Release powder by removing thumb; powder must flow freely into a 250 ml cylindrical flask.
• Transfer powder to a conical flask, cork it, and vibrate at 200 vibrations/min for 2 hours.
• After vibration, powder must still flow smoothly without clogging.

Related Important Tests:

• Particle Size Distribution (Clause 2.2):

  • 100% passes through 120 µm IS sieve
  • ≥90% passes through 75 µm IS sieve
  • ≤10% passes through 38 µm IS sieve
  • Sieving duration: 30 min (hand), 110 min (machine)

• Apparent Density (Clause 2.1.1):

  • Apparent density = (\frac{100}{\text{Volume of powder (ml)}}) g/ml
  • Use 100 g powder in a 250 ml cylinder, rotate 10 cycles, settle 60 sec, measure volume.

• Heat Test (Clause 2.6):

  • 200 g powder in a 75 mm dia × 50 mm deep tin cup.
  • Heat at 60°C for 1 week.
  • Powder must not cake or form lumps that fail flow test.

Summary Table: Free Flow Test Setup

flowchart LR
    A[100 g Powder] --> B[Glass Funnel (7.5 cm dia)]
    B --> C[Release powder into 250 ml Flask]
    C --> D{Does powder flow freely?}
    D -- Yes --> E[Transfer to Conical Flask]
    E --> F[Mechanical Vibrator (200 vib/min, 2 hrs)]
    F --> G{Powder flows smoothly after vibration?}
    G -- Yes --> H

IS 4861 Fire Extinguishment Test (Clause 2.7) - Key Specifications & Setup

• Tray Dimensions:

  • Base: 1 m × 1 m (square)
  • Three vertical sides: 55 mm high
  • One vertical side: 40 mm high
  • Material: Steel plates, thickness ≥ 6 mm
  • Reinforcement: Continuous angle iron along three sides, top edge width ≥ 45 mm
  • Tray height from ground: ≥ 45 cm (on metal stand)

• Test Procedure:

  • Spread 25 mm thick dry sand layer uniformly inside the tray
  • Spread 500 g magnesium turnings/chips over 0.10 m² area
  • Ignite magnesium uniformly until fully alight
  • Apply 2 kg dry powder gently within 60 seconds
  • Fire must be completely extinguished
  • Leave for 30 minutes undisturbed
  • Remove upper crust; no unburnt powder should remain

Effectiveness Criterion: No unburnt powder left after 30 minutes indicates successful extinguishment.

Additional Heat Stability Test (Clause 2.6)

• Sample: 200 g dry powder in tinned steel cup (75 mm diameter, 50 mm deep)
• Condition: Oven at 60°C for 1 week
• Test: Check for caking/lumps; lumps dropped from 1 m must be friable (break easily)
• Purpose: Ensures powder stability at elevated temperatures

flowchart TD
    A[Prepare Tray] --> B[Spread 25mm Dry Sand]
    B --> C[Spread 500g Mg Chips on 0.10 m²]
    C --> D[Ignite Mg Chips]
    D --> E[Apply 2kg Dry Powder in 60s]
    E --> F[Observe Fire Extinguishment]
    F --> G[Wait 30 min undisturbed]
    G --> H[Remove Crust & Check Powder]
    H --> I{No unburnt powder?}
    I -- Yes --> J[Pass Test]
    I -- No --> K[Fail Test]

This test ensures the dry powder's effectiveness in extinguishing burning metal fires per IS 4861 standards.

IS 4861: Packaging and Containers - Key Points

Container Strength (Clause 3.3)

• Load test: Container must bear a 10 kg mass on a flat surface without distortion or failure.
• Drop test: No significant disintegration when dropped from 1 m height onto concrete.

Plastic Bag Sizes (Clause 3.2)

• Standard dimensions for powder packing:
  • 300 × 300 mm
  • 450 × 450 mm
  • 600 × 600 mm

Labelling Requirements (Clause 4.1)

Each pack must be labelled with:

• Manufacturer's name or trademark
• Quantity of powder
• Suitability for metal fires
• Date of manufacture

Additional Specification (Clause 4.1.1)

• Packing may carry the Standard Mark for certification.

Summary Table: Plastic Bag Sizes

This ensures packaging integrity and clear identification for safe handling and storage.

IS 4861 - Container Strength Key Points

• Strength Requirement (Clause 3.3):

  • No distortion/failure when placed on a flat surface under 10 kg mass.
  • No disintegration when dropped from 1 m height onto concrete after packing.

• Plastic Bag Sizes (Clause 3.2):

  • 300 × 300 mm
  • 450 × 450 mm
  • 600 × 600 mm

• Filling Capacity (Clause 3.2.1):

  • Bags filled to 3/4 of their capacity.

Practical Implications for Container Strength

• Load Bearing: Container must sustain a uniform load of 10 kg without permanent deformation.
• Drop Test: Must resist impact damage from 1 m drop onto hard surface.

Summary Table

flowchart LR
    A[Plastic Container] --> B[Load Test: 10 kg on flat surface]
    A --> C[Drop Test: 1 m on concrete]
    B --> D{No Distortion/Failure}
    C --> E{No Disintegration}

This ensures container durability during handling and transport as per IS 4861.

Key Specifications for Filling of Bags (IS 4861):

• Bag Sizes (Clause 3.2):

  • Plastic bags:
    • 300 × 300 mm
    • 450 × 450 mm
    • 600 × 600 mm

• Filling Quantity (Clause 3.1 & 3.2.1):

  • Plastic bags: 10 kg and 25 kg powder quantities
  • Jute bags: 50 kg powder quantity
  • Bags shall be filled to three-fourths (¾) of their capacity (Clause 3.2.1).

• Jute Bags (Clause 3.4):

  • Shall conform to IS 7406 (Part 2) - 1980 for quality and dimensions.

Practical Notes:

• Filling at ¾ capacity ensures ease of handling and prevents bursting.
• Dimensions relate to bag flat measurements; volume depends on bag thickness and powder density.
• For 50 kg jute bags, ensure compliance with IS 7406 for strength.

Summary Table:

For detailed jute bag specs, refer to IS 7406 (Part 2) - 1980.

IS 4861: Marking and Labeling Key Points

Clause 4.1: Labeling Requirements on Packs Containing Dry Powder

Each pack must be labeled with:

• Manufacturer's name or trademark
• Quantity of the powder
• Suitability for metal fires
• Date of manufacture

Clause 4.1.1: Packing Marking

• Packing may also bear the Standard Mark.

Clause 4.1.2: Use of Standard Mark

• Governed by the Bureau of Indian Standards Act, 1986.
• License conditions for using the Standard Mark are regulated by BIS.

Summary Table: Labeling Information on Dry Powder Packs

Notes:

• Marking ensures traceability, quality assurance, and compliance.
• Standard Mark usage requires BIS licensing.
• Labels must be clear, durable, and legible.

flowchart TD
    A[Pack Containing Dry Powder] --> B[Labeling]
    B --> C[Manufacturer's Name/Trademark]
    B --> D[Quantity of Powder]
    B --> E[Suitability for Metal Fires]
    B --> F[Date of Manufacture]
    B --> G[Standard Mark (optional)]

This concise labeling ensures compliance with IS 4861 for dry powder packaging.

IS 4861: Test Methods for Dry Powder for Fighting Fires in Burning Metals

Key Specifications & Test Methods

• Particle Size Distribution (Clause 2.2):

  • 100% passes through 120 μm IS Sieve
  • ≥90% passes through 75 μm IS Sieve
  • ≤10% passes through 38 μm IS Sieve
  • Sample: 100 g dry powder
  • Sieving time: 30 min (hand) / 110 min (machine)
  • Follow IS:1607-1977 for test sieving procedure.

• Heat Test (Clause 2.6):

  • Sample: 200 g dry powder in tinned steel cup (75 mm diameter, 50 mm deep)
  • Oven temperature: 60°C for 1 week
  • Post-test: Check for caking/lump formation.
  • Lump dropped from 100 cm must be friable (breakable).
  • Ensures powder stability at elevated temperatures.

• Rounding Off (Clause 0.5):

  • Final test values rounded per IS:2-1960.
  • Retain significant figures equal to the specified value.

Summary Table: Particle Size Limits

This ensures powder quality, stability, and effectiveness in fire-fighting applications.

IS 4861 - Application Techniques: Key Specifications

• Particle Size Distribution (Clause 2.2):

  • 100% passes through 120 µm IS Sieve
  • ≥90% passes through 75 µm IS Sieve
  • ≤10% passes through 38 µm IS Sieve
  • Test sample: 100 g powder
  • Sieving duration: 30 min (hand), 110 min (machine) (per IS 1607:1977)

• Powder Packaging (Clause 3.2):
  Plastic bags sized:

  • 300 × 300 mm
  • 450 × 450 mm
  • 600 × 600 mm

• Rounding Off (Clause 0.5):
  Follow IS 2:1960 for rounding test results, matching significant figures with specified values.

Application Methods (General from IS 4861 context)

• Dry powder applied by:
  • Spraying
  • Dipping
  • Brushing
  • Other site-appropriate methods

Summary Table: Particle Size Distribution

This ensures uniform powder quality for effective application and adherence to IS standards.