Head injuries are among the most serious and potentially fatal hazards in industrial workplaces. To safeguard workers in industries such as construction, mining, tunnelling, shipbuilding, and heavy engineering, the Indian Standard IS 2925:1984 specifies the requirements for industrial safety helmets. First published in 1964 and revised in 1975, the current (second) revision incorporates practical updates, including the provision for ventilation holes and relaxation of cradle anchoring points, making helmets more versatile and comfortable.
This standard ensures that helmets provide adequate protection against falling objects, impact forces, and associated hazards commonly faced in industrial environments. It also aligns with international practices, being technically equivalent to ISO 3873.
Contents
Scope
The standard defines the materials, construction, workmanship, finish, sizes, and performance requirements of industrial safety helmets. It covers helmets designed to protect against falling objects and general industrial hazards, but special requirements may apply where exposure to chemicals, oils, or other unique risks is present.
Key Terminology
- Brim – Rim surrounding the shell.
- Chinstrap – Adjustable strap under the chin for securing the helmet.
- Harness – Assembly maintaining helmet position, including headband and cradle.
- Cradle – Straps providing clearance and shock absorption.
- Peak – Extension of shell above eyes.
- Shell – The hard, smooth outer material.
- Ventilation Holes – Openings for air circulation inside the helmet.
Materials
- Shell – Made of non-metallic material, tested for durability and resistance.
- Harness – Sweat-resistant, non-irritant, and skin-safe material.
- Metal parts – Corrosion-resistant or specially treated; aluminium/magnesium parts are prohibited in underground mines due to fire risks.
Sizes
Helmets are available in three nominal sizes based on headband circumference:
- Small: 500–540 mm
- Medium: 540–590 mm
- Large: 590–640 mm
Adjustability is essential, ensuring proper fit across head sizes.
Construction Requirements
- Shell Design – Dome-shaped with a continuous brim, with or without a peak. No metallic component should pass through the shell.
- Ventilation – Optional, but where present, holes must not exceed 6 mm diameter and maintain safe spacing.
- Harness – Minimum 30 mm wide headband, with at least 4 anchoring points for cradle straps, ensuring:
- 30 mm clearance above head
- 80 mm wearing depth
- Chinstrap/Nape Strap – At least 19 mm wide, strong, and adjustable.
- Additional Fittings (where required):
- Lamp Bracket for miners.
- Cable Clip for secure attachment.
Performance Requirements
Helmets must undergo rigorous testing:
- Shock Absorption – Withstand impact without transmitting force greater than 5 kN to the headform.
- Penetration Resistance – Must not be pierced or dented beyond 10 mm by a pointed impact.
- Flammability Resistance – Should self-extinguish within 5 seconds after flame removal.
- Electrical Resistance – Leakage current must not exceed 3 mA under 2000 V AC.
- Water Absorption – Maximum of 5% increase in mass after immersion.
- Heat Resistance – No distortion or softening at 93 ± 5°C.
Workmanship and Finish
Helmets must have a smooth surface free of burrs and sharp edges. All fittings should be securely attached and corrosion-free.
Weight
The maximum mass of a helmet (without attachments) should not exceed 400 grams. If heavier, the exact weight must be labeled.
Marking and Instructions
Every helmet must display:
- Manufacturer’s name or trademark.
- Helmet size.
- BIS certification mark (if licensed).
User instructions must include:
- Proper fitting and adjustment for protection.
- Replacement of helmets subjected to severe impact.
- No unauthorized alterations to structure or parts.
Testing Methods
The standard prescribes detailed test methods for each requirement, such as:
- Shock Absorption Test (Appendix E)
- Penetration Test (Appendix F)
- Flammability Test (Appendix G)
- Electrical Resistance Test (Appendix H)
- Water Absorption Test (Appendix J)
- Heat Resistance Test (Appendix K)
These tests ensure helmets maintain structural integrity and protective function under extreme conditions.
The IS 2925:1984 standard serves as a cornerstone in occupational safety, ensuring industrial helmets deliver reliable head protection. By defining strict requirements for design, material, performance, and testing, it minimizes risks of head injuries in hazardous workplaces. Compliance with this standard not only fulfills legal safety obligations but also reinforces a strong safety culture, safeguarding the workforce in industries where accidents from falling objects and impacts are prevalent.
