Specification for dry powder for fighting fires in burning metals
1984 Edition

Overview of Scope and Compliance Criteria

• Applicable to dry powders with defined particle size parameters.
• Test results and measurements are rounded following the guidelines in IS:2-1960.
• Usage of the Standard Mark adheres to the BIS Act, 1986.

Particle Size Distribution (Clause 2.2)

• Sampling involves a 100 g dry powder sample.
• Sieving durations: 30 minutes manually, 110 minutes mechanically.
• Testing follows procedures outlined in IS:1607-1977.

Rounding Guidelines (Clause 0.5)

• Final analytical values rounded in accordance with IS:2-1960.
• Maintain the same significant figures as those specified in the standard.

Additional Information

• The Standard Mark is regulated as per the BIS Act, 1986.
• This edition reflects updates based on Defence Institute of Fire Research findings since 1968.

flowchart LR
    Powder[Dry Powder] --> PSD{Particle Size Distribution}
    PSD --> Pass120[100% pass 120 μm sieve]
    PSD --> Pass75[≥ 90% pass 75 μm sieve]
    PSD --> Pass38[≤ 10% pass 38 μm sieve]
    Testing[Testing & Analysis] --> Rounding[Rounding per IS:2-1960]
    Mark[Standard Mark Usage] --> BIS[BIS Act, 1986 Regulation]

This section guarantees powder quality and consistency with BIS standards.

Detailed Requirements for Dry Powder Used in Metal Fire Extinguishing

Particle Size Requirements (Clause 2.2)

• 100% must pass through a 120 μm IS sieve.
• At least 90% must pass through a 75 μm IS sieve.
• No more than 10% may pass through a 38 μm IS sieve.

Testing Methodology

• Sample size: 100 g of dry powder.
• Sieving conducted as per IS:1607-1977.
• Duration: 30 minutes for hand sieving, 110 minutes for mechanical sieving.

Rounding Off Results (Clause 0.5)

• Test and analysis results rounded according to IS:2-1960.
• Keep the same number of significant digits as specified.

Particle Size Summary Table

flowchart LR
    Sample[100 g Powder Sample] --> Sieving{Sieving Method}
    Sieving --> Hand[Hand Sieving - 30 min]
    Sieving --> Machine[Machine Sieving - 110 min]
    Hand & Machine --> Measure[Measure % Passing]
    Measure --> Check120[Check 100% passes 120 μm]
    Measure --> Check75[Check ≥ 90% passes 75 μm]
    Measure --> Check38[Check ≤ 10% passes 38 μm]

This ensures the powder’s fineness to effectively suppress metal fires in line with IS 4861.

Apparent Density Measurement of Dry Powder (Clause 2.1)

Requirements

• Apparent density should be within 0.75 g/ml to 1.18 g/ml.

Procedure

1. Take 100 g of dry powder.
2. Place in a 250 ml graduated glass cylinder with a stopper (per IS:878-1975).
3. Rotate the cylinder gently end over end for 10 full turns.
4. Set upright, allow powder to settle for 60 seconds.
5. Level the powder surface carefully.
6. Record the volume occupied (V ml).

Calculation

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

This method ensures consistent bulk density measurement crucial for quality assurance.

Evaluation of Free-Flow Properties (Clause 2.5)

Procedure

• Place 100 g of dry powder in a glass funnel with 7.5 cm diameter outlet plugged.
• Remove the plug to allow powder to flow into a 250 ml cylindrical flask.
• Powder must flow freely without obstruction.
• Transfer powder to a conical flask, seal it, and subject it to vibration at 200 vibrations per minute for 2 hours.
• After vibration, powder should continue to flow smoothly without clogging.

Related Tests

• Particle size distribution as per Clause 2.2.
• Apparent density measurement per Clause 2.1.1.
• Heat stability test (Clause 2.6) involving heating 200 g powder at 60°C for one week, ensuring no caking or lump formation.

flowchart LR
    Start[100 g Powder] --> Funnel[Glass Funnel (7.5 cm diameter)]
    Funnel --> Release[Remove plug]
    Release --> Flow[Powder flows into 250 ml Flask]
    Flow --> CheckFlow{Does powder flow freely?}
    CheckFlow -- Yes --> Transfer[Transfer to Conical Flask]
    Transfer --> Vibrate[Vibrate at 200 vibrations/min for 2 hrs]
    Vibrate --> PostCheck{Flow smooth after vibration?}
    PostCheck -- Yes --> Pass[Passes Flow Test]
    PostCheck -- No --> Fail[Fails Flow Test]
    CheckFlow -- No --> Fail

This test confirms powder’s ability to flow freely and maintain stability under agitation.

Procedure for Assessing Fire Extinguishing Capability (Clause 2.7)

• Use a square steel tray with dimensions:
  • Base: 1 m x 1 m.
  • Three vertical sides: 55 mm in height.
  • One vertical side: 40 mm in height.
  • Steel thickness: minimum 6 mm.
  • Reinforced edges with continuous angle iron at least 45 mm wide.
• Tray mounted on a stand at a height not less than 45 cm from the ground.
• Spread a uniform 25 mm layer of dry sand on the tray’s base.
• Scatter 500 g of magnesium turnings/chips over an area of 0.10 m².
• Ignite magnesium uniformly until fully alight.
• Gently apply 2 kg of dry powder within 60 seconds.
• Fire must be completely extinguished.
• Leave the setup undisturbed for 30 minutes.
• Remove top crust; no unburnt powder should remain.

Acceptance Criterion: Absence of unburnt powder after 30 minutes confirms successful extinguishment.

Heat Stability Test (Clause 2.6)

• 200 g powder sample placed in a tinned steel cup (75 mm diameter, 50 mm depth).
• Heated at 60°C for one week.
• Post-test, powder must not cake; lumps dropped from 1 m should break apart easily.

flowchart TD
    PrepareTray[Prepare Steel Tray] --> SpreadSand[Spread 25 mm Dry Sand]
    SpreadSand --> ApplyMg[Apply 500 g Magnesium Chips]
    ApplyMg --> Ignite[Ignite Magnesium]
    Ignite --> ApplyPowder[Apply 2 kg Dry Powder within 60s]
    ApplyPowder --> Extinguish[Observe Fire Extinguishment]
    Extinguish --> Wait[Wait 30 minutes undisturbed]
    Wait --> RemoveCrust[Remove top crust & inspect powder]
    RemoveCrust --> Check[Lump-free, no unburnt powder?]
    Check -- Yes --> Pass[Test Passed]
    Check -- No --> Fail[Test Failed]

This test validates the powder’s effectiveness in controlling and suppressing metal fires per the standard.

Packaging Guidelines and Container Durability (Clauses 3.2, 3.3, and 4.1)

Container Strength

• Containers must support a static load of 10 kg on a flat surface without deformation or damage.
• Must endure a drop from a height of 1 meter onto concrete without significant disintegration.

Plastic Bag Dimensions

• Standard plastic bag sizes:
  • 300 mm x 300 mm
  • 450 mm x 450 mm
  • 600 mm x 600 mm

Labeling Criteria

Each package must be clearly marked with:

• Manufacturer’s name or logo.
• Net powder weight.
• Indication of suitability for metal fire applications.
• Date of manufacturing.
• Optional: BIS Standard Mark with proper licensing.

These provisions ensure safe handling, transport, and identification of the powder packages.

Essential Container Strength Requirements (Clause 3.3)

• Must withstand a uniform load of 10 kg when placed flat, without bending or damage.
• Must resist breakage or rupturing when dropped from 1 meter onto a hard surface.

Plastic Bag Size Standards (Clause 3.2)

• Dimensions:
  • 300 x 300 mm
  • 450 x 450 mm
  • 600 x 600 mm
• Bags are filled to three-quarters (75%) capacity.

flowchart LR
    Container[Plastic Container] --> LoadTest[Load Test: 10 kg on flat surface]
    Container --> DropTest[Drop Test: 1 m onto concrete]
    LoadTest --> PassLoad{No Distortion?}
    DropTest --> PassDrop{No Disintegration?}

This section defines packaging durability to safeguard powder integrity.

Specifications for Filling Dry Powder Bags (Clauses 3.1, 3.2, and 3.4)

• Plastic bag sizes:
  • 300 x 300 mm
  • 450 x 450 mm
  • 600 x 600 mm
• Filling quantities:
  • Plastic bags: 10 kg and 25 kg powder.
  • Jute bags: 50 kg powder.
• Filling level: bags filled to 75% of their capacity to ensure ease of handling and prevent rupture.
• Jute bags must comply with IS 7406 (Part 2) - 1980 for quality and dimension standards.

Refer to IS 7406 (Part 2) - 1980 for detailed jute bag specifications.

Labeling Requirements for Dry Powder Packaging (Clause 4.1)

Each package must be clearly marked with:

• Manufacturer’s name or trademark.
• Net quantity of the powder.
• Confirmation of suitability for extinguishing metal fires.
• Manufacturing date.
• Optional: The BIS Standard Mark, subject to licensing requirements.

Regulatory Compliance (Clause 4.1.2)

• Use of the Standard Mark is governed by the Bureau of Indian Standards Act, 1986.
• Licensing conditions regulate the authorization to display the Standard Mark.

flowchart TD
    Package[Dry Powder Package] --> Label[Labeling]
    Label --> Manufacturer[Manufacturer Name/Trademark]
    Label --> Quantity[Powder Quantity]
    Label --> Suitability[Suitability for Metal Fires]
    Label --> Date[Date of Manufacture]
    Label --> BISMark[Standard Mark (optional)]

Proper labeling ensures traceability, compliance, and user information.

Testing Protocols for Dry Powder Specifications

Particle Size Analysis (Clause 2.2)

• 100% must pass through a 120 μm IS sieve.
• At least 90% must pass through a 75 μm IS sieve.
• No more than 10% should pass through a 38 μm IS sieve.
• Sample size: 100 g dry powder.
• Sieving duration: 30 minutes by hand or 110 minutes by machine.
• Test methods as per IS:1607-1977.

Heat Resistance Test (Clause 2.6)

• 200 g sample placed in a tinned steel cup (75 mm diameter, 50 mm depth).
• Heated at 60°C for one week.
• Check for caking or lump formation.
• Lumps dropped from 1 m must crumble easily.

Rounding Off (Clause 0.5)

• Final results rounded following IS:2-1960.
• Maintain the same significant figures as the standard values.

These tests assure powder quality, stability, and performance for metal fire suppression.

Recommended Methods for Applying Dry Powder (General Overview)

• Particle size distribution must meet the standards specified (Clause 2.2).
• Powder packaging includes plastic bags of sizes 300 x 300 mm, 450 x 450 mm, and 600 x 600 mm (Clause 3.2).
• Rounding off of test results conforms to IS 2:1960 (Clause 0.5).

Application Techniques

• Applying dry powder by spraying from an extinguisher with an applicator for controlled dispersion.
• Direct placement of dry powder-filled plastic bags onto burning metals to smother flames.

This ensures the powder meets quality requirements and is applied effectively according to IS guidelines.