Specification for Non-Metal Helmets for Firemen and Civil Defense Personnel
1983 Edition

Overview of Scope and Specifications

• Details material and dimension requirements for protective helmets.
• Incorporates definitions and sampling procedures aligned with IS 9695-1980.
• Includes flame exposure testing with precise parameters.

Performance Parameters

Additional Considerations

• Burner flame test validates heat resistance of helmet materials.
• Brim shape and width are critical for structural integrity.
• Visor mounting holes are optional and created only if a visor is fitted.

This section clarifies terms related to helmets for firefighting and civil defense use, focusing on:

• Material specifications for durability and protection.
• Manufacturing quality and workmanship standards.
• Surface finish and acceptable weight limits.
• Performance benchmarks under test conditions.

Key Testing Parameters

Sampling and acceptance criteria refer to IS 9695-1980.

Helmet material requirements per IS 2745 include:

• Conformance with IS 9695-1980 sampling and acceptance criteria.
• Materials must provide sufficient flame resistance, durability, and protection.
• Burner test conditions specify:
  • Flame height of 150 mm.
  • Fuel maintained at 760 ± 75 mm above burner base.
  • Copper wire positioned 50 mm above burner that melts within 6 seconds to confirm flame intensity.

These ensure helmets meet essential safety and performance criteria.

Key design and dimension standards include:

• Concrete block for support: 1 m (height) × 1 m (length) × 0.6 m (width), weighing 1 tonne, placed on dry sand over solid flooring.
• Helmet sizes vary with inside headband circumference from 530 mm to 620 mm, with ±3 mm tolerance.
• Burner test configuration requires a flame height of 150 mm and fuel level at 760 ± 75 mm.
• Brim must be integral and continuous according to specified dimensions; visor fixing holes are optional if a visor is used.

Details on helmet parts:

• Shell: Smooth surface without sharp edges, shaped per standard figures, free of metal except for visor attachments.
• Padding: Minimum thickness of 8 mm, covering all inner surfaces except 15–25 mm near retention anchors; no gaps exceeding 5 mm; padding must be securely fixed.
• Headform and chinstrap: Chin strap fastened via two metal rollers (12.5 ± 0.5 mm diameter, 76 ± 0.5 mm apart) to simulate realistic load transfer.
• Helmet sizing: Inside headband circumferences from 530 to 620 mm with ±3 mm tolerance.
• Shock absorption testing after conditioning at specified temperatures and water flow rates.

Quality and finishing requirements ensure:

• Compliance with IS 9695-1980 for sampling and conformity.
• Visor mounting holes should be at least 5 mm in diameter and meet IS 9995-1981 specifications.
• Burner flame test parameters: 150 mm flame height, 760 ± 75 mm fuel level, copper wire melting within 6 seconds.
• Helmets must have smooth finishes, no sharp edges, and firmly fixed components to maintain durability and safety.

Each helmet must be marked clearly and indelibly with:

• Manufacturer’s name or trademark.
• Size along with color coding.
• Year of manufacture.
• Indication of visor presence (with or without).

The standard mark may be applied subject to BIS licensing as per the Bureau of Indian Standards Act, 1986.

Sampling is conducted in accordance with IS 9695-1980:

• Random samples drawn from production batches.
• Performance testing includes shock absorption after conditioning at 65 ± 2°C (oven), 10 ± 2°C (refrigerator), and water flow at 1 L/min for 4 hours.
• Mass limits exclude visor: maximum 800 grams; if exceeded, mass marked rounded to nearest 30 grams.

These procedures ensure helmets meet safety and quality benchmarks.

Performance requirements emphasize:

• Retention system strength tested to withstand specified tensile loads without failure.
• Material quality assessed for impact resistance and durability.
• Helmets must maintain structural integrity under impact and retention load tests.
• Workmanship ensuring smooth surfaces without defects.

Sampling and acceptance follow IS 9695-1980, with numerical values rounded per IS guidelines.

Mandatory markings include:

• Manufacturer’s identification.
• Size with color.
• Year of manufacture.
• Visor status indication.

The Standard Mark may be used under BIS licensing conditions, certifying conformity with IS 2745.

Helmets undergo conditioning at:

• 65 ± 2°C for 4 hours (oven).
• 10 ± 2°C for 4 hours (refrigerator).
• Water flow at 1 L/min for 4 hours at ambient temperature.

Following conditioning, helmets are mounted on wooden headforms and subjected to impact by dropping a striker from 2.5 m ± 5 mm. Impact forces are recorded using photographic or high-speed instrumentation to evaluate energy absorption.

Penetration tests follow immediately after shock absorption testing:

• Plate Test: No helmet failure or deformation allowing contact with wooden headform; no dents or penetration.
• Plumb Bob Test: Maximum dent or penetration limited to 10 mm; no failure allowing helmet displacement over headform.

Striker weight is 3 ± 0.05 kg dropped from 2.5 m ± 5 mm.

The retention system (headband, chin strap, cradle) is tested as follows:

• Apply preload of 0.25 kN for 30 seconds.
• Increase load at 1 kN/min to 0.5 kN and hold for 2 minutes.
• Measure elongation; maximum allowable extension difference between preload and maximum load is 25 mm.

No failure or excessive stretch is permitted under these conditions.

Helmets are inverted on a wire frame within a container filled with 6 g/L sodium chloride solution, soaked for 18-24 hours at 27 ± 2°C. An AC voltage of 2000 V RMS at 50-60 Hz is applied for 1 minute between internal and external electrodes. Leakage current must not exceed 3 mA at 2000 V, and no electrical breakdown should occur.

Post shock absorption test helmets are weighed dry, immersed in water at 27 ± 2°C for 24 hours, then surface wiped and weighed again. Water absorption percentage is calculated as:

Water Absorption (%) = ((Wet Weight - Dry Weight) / Dry Weight) × 100

Maximum allowed water uptake is 5% of dry mass.

Using a Barthel burner per IS 4355-1967, the helmet mounted on a wooden headform is exposed to flame at 12 cm below the crown, rotated at 2 revolutions per minute for one full rotation. No visible flame penetration inside the helmet is permitted during or after the test, ensuring flame resistance.