Safety Protocol Specification
ISI IS 4151
Story & Background
ISI IS 4151 is the mandatory certification for all motorcycle helmets sold in India. It was recently updated to ban non-ISI helmets to improve the safety of the world's largest two-wheeler market.
1993
First release of Indian Standard IS 4151 regulating motorcycle protective helmets.
2015
Major revision aligning testing requirements closely with ECE principles.
2018
Government of India mandates ISI certification for all helmet manufacturing and sales.
2024
Strict enforcement banning non-ISI helmets to eliminate unsafe counterfeit imports.
Testing Protocol & Methods
Bureau of Indian Standards
- Impact Absorption: Maximum acceleration not to exceed 150g.
- Penetration: Tested with a 3kg striker.
- Retention: Static and dynamic tests for chin straps.
Technical Specifications & Performance
Impact G-Force
300G Max
Drop Velocity
7.0 m/s
Retention Load
150 kg static
Rigidity Test
Transverse Load
ISI IS 4151 vs DOT FMVSS 218
Comparing legal minimums for India and the USA
DOT FMVSS 218
Max G-Force Allowance: 400G
Government Lab Audit: No
ISI IS 4151
Benchmark
Max G-Force Allowance: 300G
Government Lab Audit: Yes (Mandatory BIS)