Specification for Industrial Safety Helmets(Bi-Lingual)
1984 Edition

Overview of Scope and Size Parameters for Industrial Helmets

Scope (Clause 2.0)

• Defines terminology associated with industrial safety helmets.
• Helmets intended to safeguard workers from head trauma in industrial settings.

Size Specifications (Clause 4.1 & 2000 Amendment)

• Helmets offered in sizes based on the internal headband circumference:

• Updated sizes include: 520, 530, 540, 550, 560, 570, 580, 590, 600 mm.
• Helmets must have clear size markings and adjustable headbands for fit.

Additional Information

• Headband continuity is optional if a nape strap is present (Clause 2.3.1).
• Flammability testing procedures are detailed in Appendix G (Clause 8.3).

Summary Table: Helmet Size and Headband Range

This ensures helmets accommodate varying head dimensions while complying with safety standards.

Definitions and Key Terms in Helmet Standards

Clause 2.0: Terminology

• Establishes clear definitions for terms related to industrial helmets for consistency.
• Essential for understanding components, testing methods, and usage.

Clause 4.1: Helmet Size Ranges

• Helmets must include adjustable headbands fitting these ranges.

Clause E-2.4: Impact Test Block Specifications

• Monolithic concrete or equivalent block used for impact testing.
• Minimum dimensions:
  • Height: 1 meter
  • Length: 1 meter
  • Width: 0.6 meter
  • Mass: Approximately 1 tonne
• Block placed on dry sand over a solid floor for stability.

Summary:

• Clarifies helmet-related vocabulary.
• Defines proper sizing for secure fit.
• Standardizes impact test setup.

flowchart LR
A[Helmet] --> B[Adjustable Headband]
B --> C{Size}
C -->|Small| D[500-540 mm]
C -->|Medium| E[540-590 mm]
C -->|Large| F[590-640 mm]
G[Test Block]
G --> H[Dimensions: 1m x 1m x 0.6m]
G --> I[Mass: 1 tonne]
G --> J[Placed on dry sand]

Refer to additional clauses in IS 2925 for detailed material and testing requirements.

Material Requirements for Helmet Components

• Helmet Shell: Must endure 15 minutes at 93 76C without warping, separation, or softening (Clause 2.1).
• Strap Cross-sectional Area: Minimum of 180 mm8 as per Amendment No.1.
• Corrosion Resistance: Metal elements tested following Appendix B (Clause 3.3) to confirm durability.
• Water Absorption: Assessed according to Appendix J (Clause 8.5) ensuring structural integrity in wet environments.
• Salt Spray Test: Metal parts exposed to sodium chloride solution to verify corrosion protection (Amendment No.1).

Testing Overview

These ensure helmets meet the necessary standards for protection, durability, and wearer comfort.

Helmet Size Specifications and Sizing Options

Clause 4.1 (Amendment December 2000):

• Helmets are manufactured in the following internal headband circumferences:

• Sizes can be achieved using combinations of shells and headbands.
• Helmets must clearly indicate the adjustment range.

Additional Details

• S-hook Dimensions (Clause 2.3): Approximate height 100 mm, width 50 mm, constructed from 10 or 12 mm steel rod.
• Headband may be continuous or segmented if a nape strap is utilized (Clause 2.3.1).

Visual Summary

flowchart LR
    H[Helmet Size] --> I[Shell + Headband]
    I --> J{Adjustment Range}
    J -->|520-600 mm| K[Marked on Helmet]
    S[S-hook] --> T[Dimensions: 100 mm x 50 mm, steel rod]

Always consult the most recent IS 2925 amendment for precise sizing and manufacturing standards.

Construction Standards and Test Setup Specifications

Support Block (Clause 2.4):

• Constructed from concrete or similar monolithic material.
• Minimum dimensions:
  • Height: 1 m
  • Length: 1 m
  • Width: 0.6 m
• Approximate mass: 1 tonne.
• Placed on a dry sand bed over a solid floor for stability during testing.

Headband Size Tolerance (Clause 4.1.1):

• Allowed tolerance: 710 mm.
• Measurement performed using fixed ring gauges, expanding metal gauges, or headforms.

Support Block Dimension Summary

Additional Notes

• The block provides a stable foundation for helmet impact tests.
• Bedding on dry sand ensures uniform support.
• Proper headband sizing tolerance guarantees safety and comfort.

flowchart TD
    B[Concrete Support Block] --> C[Supports Gauge and Headform]
    B --> D[Dimensions: 1m x 1m x 0.6m]
    B --> E[Mass: Approximately 1 tonne]
    B --> F[Bedding on dry sand]

This setup is essential for reliable helmet impact testing under IS 2925.

Workmanship and Finishing Requirements

• Surface Quality (Clause 6.1):

  • Helmet exterior must be smooth and free from burrs.
  • All sharp edges must be eliminated for safe and comfortable contact.
  • Metal parts, including rivets, should be smooth and free from rough projections.

• Cable Clip Specifications (Clause 5.5):

  • Constructed from plastic or other appropriate materials.
  • Firmly attached to helmet shell.
  • Tested by suspending a 2.25 kg weight from a 50 cm cord attached to the clip.
  • The weight is dropped twice from 30 cm height.
  • The clip must remain undamaged after testing.

• Wooden Headform (Clause 5.5):

  • Used for mounting helmets during testing to ensure correct positioning.

• Additional Tests:

  • Corrosion resistance of metal components (Appendix B, Clause 3.3).
  • Helmet penetration resistance (Appendix F, Clause 8.2).

Cable Clip Drop Test Summary

flowchart TD
    A[Helmet with Cable Clip] --> B[Attach 2.25 kg weight via 50 cm cord]
    B --> C[Drop weight from 30 cm height]
    C --> D{Is Clip Undamaged?}
    D -- Yes --> E[Pass]
    D -- No --> F[Fail]

These requirements ensure the helmet’s components maintain integrity and safety.

Helmet Mass Criteria and Labeling Requirements

• Maximum Weight:

  • Complete helmet (excluding attachments and peak) should not exceed 400 g (Clause 7.1).
  • If heavier, weight must be rounded to nearest 35 g and marked on the helmet.

• Water Absorption Limit:

  • Absorption should not exceed 5% of the helmet’s mass (Clause 8.5, Appendix J).

• Load Test for Wearing Clearance:

  • Helmet mounted on IS 7692 headform subjected to 10 kg load.
  • Minimum clearance from headform top to bottom edge of nape strap must be 115 mm (Clause 5.3.2.1).

• Clearance Measurement:

  • Use a rod not exceeding 10 mm diameter inserted along vertical axis of headform.
  • Adjust clearance for helmets with reinforcing ribs by factoring rib depth (Clause 2.1).

Summary Table

flowchart LR
    H[Helmet] --> I[Mass 6 400 g?]
    I -- Yes --> J[No Label Needed]
    I -- No --> K[Label Mass Rounded to 35 g]
    H --> L[Water Absorption Test]
    L --> M[Absorption 4 5% of mass]
    H --> N[Load Test with 10 kg]
    N --> O[Clearance 115 mm]

This ensures helmets meet safety, comfort, and compliance standards.

Primary Performance Requirements for Industrial Helmets

1. Weight Limit (Clause 7.1)

• Maximum helmet mass without attachments/peak: 400 grams.
• Above 400 grams, helmet must carry a mass label rounded to the nearest 35 grams.

2. Impact Shock Absorption (Clause 8.1, Appendix E)

• Helmets must withstand impact tests simulating workplace shocks.
• Test involves dropping helmet mounted on a headform from specified heights.
• The peak acceleration transmitted must be below a defined limit, typically under 250 g.

3. Flame Resistance (Clause 8.3, Appendix G)

• Helmets tested for resistance to ignition and flame.
• Materials should self-extinguish quickly and not support continuous burning after flame exposure.

Summary Table:

flowchart LR
    H[Helmet Mass 400 g] --> I[Label if Exceeded]
    H --> J[Shock Absorption Test]
    J --> K[Peak Acceleration < 250 g]
    H --> L[Flammability Test]
    L --> M[No Sustained Burning]

Refer to Appendices E and G in IS 2925 for detailed testing procedures.

Sampling Procedures and Acceptance Criteria

• Sampling Methodology: Follow IS 9695:1980 which outlines statistical sampling for industrial products.
• Sample Size and Selection: As per Clause 9.1 of IS 2925 and IS 9695, samples are drawn from production lots.
• Acceptance Criteria: Batch acceptance or rejection depends on the number of defective items found, based on Acceptance Quality Levels (AQL) defined in IS 9695.
• Heat Resistance Test: Helmets must withstand heat exposure without deforming or separating (Clause 8.6, Appendix K).

Typical Sampling Plan Summary

Refer to IS 9695 for comprehensive sampling tables.

flowchart TD
    B[Product Batch] --> C[Sample Selection per IS 9695]
    C --> D{Testing}
    D -->|Defects 4 Ac| E[Batch Accepted]
    D -->|Defects > Ac| F[Batch Rejected]

Consult IS 9695 for exact sample sizes and acceptance rules.

Marking Requirements for Industrial Helmets

Mandatory Markings (Clause 10.1)

Each helmet shell and suspension harness shall be clearly and permanently marked with:

• Manufacturer’s name or trademark
• Helmet size

Additional Marking Instructions (Clause 11.1)

Markings on the helmet or attached labels must include:

• Confirmation that helmet fits or is adjustable to the specified size.
• Statement indicating helmets absorb energy via partial destruction, and helmets subjected to severe impact should be replaced.
• Warning against any structural or component alterations to preserve protection efficiency.

Use of Standard Mark (Clauses 10.1.1 and 10.1.2)

• Helmets may bear the Standard Mark.
• Usage governed by the Bureau of Indian Standards Act, 1986.
• Licensing details available from BIS.

Marking Overview Table

Marking Process Flow

flowchart LR
    H[Helmet] --> I[Mark Manufacturer Name/Trademark]
    H --> J[Mark Helmet Size]
    H --> K[Attach Safety Instructions]
    K --> L[Fit/Adjust Size Warning]
    K --> M[Impact Damage Replacement Warning]
    K --> N[No Alteration Warning]

Procedure for Testing Helmet Sterilization

This appendix specifies how to verify helmets are free from microbial contamination, critical for medical and industrial applications.

Key Points:

• Sterilization Techniques: Usually autoclaving or chemical sterilization methods.
• Testing Process:
  • Subject helmet samples to sterilization cycles.
  • Following sterilization, incubate samples in culture media to check for microbial growth.
• Acceptance Criteria: No microbial colonies should develop after incubation, confirming sterilization effectiveness.

Related Testing Procedures in IS 2925:

Sterilization Test Flow

flowchart TD
    S[Sample Helmet] --> T[Sterilization Cycle]
    T --> U[Incubate in Culture Media]
    U --> V{Microbial Growth?}
    V -- No --> W[Pass: Sterilization Confirmed]
    V -- Yes --> X[Fail: Sterilization Inadequate]

Refer to specific sterilization standards for detailed parameters such as temperature and duration.

Testing Method for Corrosion Resistance of Metallic Components

Test Details:

• Solution Composition: 5 parts sodium chloride (NaCl) to 95 parts distilled water by weight.
• Temperature Range: 256 to 356C.
• Exposure: Continuous salt spray for 24 hours.
• Post-Test Treatment: Rinse with clean water and dry thoroughly.
• Acceptance: No visible corrosion should appear on metal parts.

Important Notes:

• Metal parts should be inherently corrosion-resistant or suitably treated.
• Helmets intended for underground mining must exclude aluminum, magnesium, and their alloys.

Summary Table

flowchart TD
    A[Prepare NaCl Solution] --> B[Continuous Spray for 24 hrs]
    B --> C[Rinse with Clean Water]
    C --> D[Dry Specimens]
    D --> E{Corrosion Present?}
    E -- No --> F[Pass]
    E -- Yes --> G[Fail]

This test verifies the corrosion resistance of metal parts in helmets.

Methodology for Assessing Clearance Above Head and Wearing Depth

Key Requirements (Clause 5.2.2 & Appendix C):

• Clearance Above Head: Minimum 30 mm space between the top of the wearer’s head and the helmet crown at smallest headband setting.
• Wearing Depth: Minimum 80 mm depth of fit at the maximum headband adjustment.
• Cradle (Headband) Requirements:
  • Anti-concussion tapes fixed at four or more anchoring points.
  • Strap width not less than 19 mm.

Measurement Procedure (Appendix C, Clause 2.1):

1. Place the helmet on a standard headform (IS 7692-1975) of appropriate size.
2. Apply a vertical load of 10 kg on the helmet’s top.
3. Insert a rod of diameter 10 mm or less through a hole on the headform’s vertical axis to measure clearance.
4. For helmets with reinforcing ribs, measure rib depth and adjust clearance values accordingly.

Summary Table

flowchart TD
    A[Mount Helmet on Headform] --> B[Apply 10 kg Load]
    B --> C[Insert 10 mm Rod Through Headform]
    C --> D[Measure Clearance Above Head]
    C --> E[Measure Wearing Depth]
    D --> F{Helmet Has Ribs?}
    F -- Yes --> G[Measure Rib Depth & Adjust]
    F -- No --> H[Use Direct Measurement]

This procedure ensures proper helmet fit and wearer protection under loading.

Shock Absorption Testing Procedure

Testing Conditions (Clause 8.1, Appendix E):

• Preconditioning: Helmet samples are subjected to one of the following for 4 hours:
  • (a) Oven at 50 7 56C
  • (b) Refrigerator at -10 7 26C
  • (c) Water flow over the helmet shell at 1 l/min at ambient temperature
• Testing: Conduct shock absorption tests within 1 minute of conditioning.
• Acceptance Criteria:
  • No penetration or cracking of the helmet shell.
  • Suspension harness remains intact and functional.
  • Maximum impact force transmitted to the base must not exceed 5 kN (510 kgf).

Test Summary

Additional Information:

• Helmets tested under worst shock absorption conditions are also subjected to penetration resistance tests.
• No shell failure or penetration allowed.

flowchart TD
    A[Condition Sample] --> B{Condition Type}
    B -->|a) Oven 507 56C| C[4 Hours]
    B -->|b) Refrigerator -107 26C| C
    B -->|c) Water Flow 1 l/min| C
    C --> D[Conduct Shock Absorption Test]
    D --> E{Force Transmitted 4 5 kN?}
    E -- Yes --> F[Pass]
    E -- No --> G[Fail]

This test verifies helmet performance under different environmental conditions.

Procedure for Penetration Resistance Testing

• Testing Timeframe: Conduct the penetration test within one minute after the shock absorption test that yielded the worst result (Clause 8.1).

• Acceptance Requirements:

  • The helmet shell must not rupture or be pierced to the degree that the headform is contacted.
  • No part of the helmet should fail or deform enough to allow it to be forced over the headform.
  • Maximum allowable penetration or dent depth, including the shell thickness, is 10 mm.

• Test Setup:

  • Utilize a pointed impactor as described in Appendix F.
  • Apply specified impact energy according to striker mass and drop height.
  • Measure penetration depth immediately after impact.

Key Specifications

This test confirms helmets maintain structural integrity against sharp impacts after shock loading.

flowchart LR
    A[Shock Absorption Test] --> B[Identify Worst Result]
    B --> C[Conduct Penetration Test Within 1 Min]
    C --> D[Impact with Pointed Striker]
    D --> E[Measure Penetration Depth]
    E --> F{Penetration 4 10 mm?}
    F -- Yes --> G[Pass]
    F -- No --> H[Fail]

Refer to Appendix F for detailed striker specifications and impact parameters.