It means the standard is legally recognised and can be used to prove compliance with PPE regulations in the UK and EU. 

EN 397:2025 being harmonised means it is now officially recognised under UK and EU PPE legislation, so helmets certified to this new standard can be CE and UKCA marked and used to demonstrate legal compliance.

What does it mean when a standard is harmonised?

When a standard is harmonised:

• It is published in the Official Journal (EU) or recognised in UK legislation
• It gives a presumption of conformity with PPE Regulation requirements
• Manufacturers can certify products against it
• Employers can specify it with confidence in risk assessments

This is the biggest change to industrial helmet standards in nearly 30 years.

The key change: Two types of helmets

EN 397:2025 introduces two clearly defined helmet types.

Type 1 helmets

• Focus on top impact (crown) protection
• Similar to EN 397:2012 performance
• Optional chinstrap
• Impact test: 49 Joules
• Force transmission limit: 5kN

Use case:
Environments where falling objects are the primary hazard.

Type 2 helmets

• Protection from top and side impacts
• Designed for multi-directional risk
• Mandatory chinstrap
• Crown impact test: 98 Joules
• Side, front and rear testing included
• Force transmission limit: 10kN

Use case:
High risk environments such as:

• Construction at height
• Infrastructure projects
• Rail, utilities and tunnelling
• Areas with fall risk or movement hazards

Chinstraps are now a serious consideration

A major shift in EN 397:2025 is how helmet retention is treated.

• Type 1: chinstrap optional, tested to 150N
• Type 2: chinstrap mandatory, tested to 500N

There is also retention testing, ensuring the helmet stays on during sudden movement or impact.
You now need to consider whether your workforce requires helmet stability, not just impact protection.

Broader protection 

EN 397:2025 introduces a risk-based approach with optional performance features.

New and updated options include:

• Off-crown penetration resistance (OCP)
  Tests protection from lateral hazards
• Electrical insulation (moved to EN 50365:2023)
  Covers higher voltages up to 17kV
• Enhanced visibility
  For both daylight and low light conditions
• Electrostatic properties
  Important for ATEX environments
• Temperature performance
  Testing above +150°C and below -20°C

Compatibility testing is now defined

EN 397:2025 introduces new compatibility requirements for helmet attachments and accessories. In accordance with the new standard, ergonomic assessments and performance tests will be carried out to verify that items are safe for use together.

Attachments fall into two categories:

• Additional protective functions
  Example: visors, face shields, ear defenders
• Accessories (non-protective)
  Example: lamps, cameras

EN 397:2025 requires:

• Testing with attachments fitted where relevant
• Defined assessment criteria
• Ergonomic testing with real users

Why this matters:
Previously, compatibility was often assumed. Now it must be verified and documented.

What happens to EN 397:2012 helmets?

There is no immediate requirement to replace existing helmets.

• Current certifications remain valid until expiry
• A transition period is expected

More information can be found on our website.

 

EN 397:2025 changes the question from:

“Do we have head protection?”

to:

“Do we have the right type of head protection for our risks?”

This puts more responsibility on:

• Health and Safety managers
• Procurement teams
• Site supervisors

to make informed decisions.

For a full technical breakdown of EN397:2025, visit our website.