A Clear View on EN ISO 16321:2022 – The New Global Standard for Eye Protection

Jul 29 2025 11:03AM

For over two decades, EN 166:2001 has been the cornerstone of safety eyewear certification across Europe and the UK. But as of May 2023, a new international benchmark has emerged: EN ISO 16321. This comprehensive standard is set to replace EN 166, bringing with it a wave of changes that will reshape how eye and face protection is tested, certified, and used in workplaces around the world.

Why the Change?

The shift to EN ISO 16321 is about global harmonisation. By aligning safety standards internationally, manufacturers and safety professionals can ensure consistent protection across borders. This is especially important in a world where supply chains and workforces are increasingly global.

Key Dates to Know

• Legal adoption date: 11 November 2025
• EN 166 certificates remain valid until their expiry (up to 5 years), meaning products certified by this date can be sold until 31 October 2029.

What’s New in EN ISO 16321?

The EN ISO 16321 series is divided into three parts:

• Part 1: General requirements for occupational eye and face protection
• Part 2: Additional requirements for welding protection
• Part 3: Additional requirements for mesh protectors

Here are the most impactful updates:

1. Expanded Headform Testing

Gone are the days of one-size-fits-all. EN ISO 16321 introduces six headform sizes (European and Asian, small to large), covering 95% of global head shapes. This ensures better fit, comfort, and protection.

2. New Impact Resistance Levels

The familiar EN 166 levels (S, F, B, A) are replaced with C, D, and E, each tied to a protection zone:

• C (45 m/s) – Orbital Protection Zone (OPZ)
• D (80 m/s) – Extended Orbital Protection Zone (EOZ)
• E (120 m/s) – Face Protection Zone (FPZ)

3. Updated Filter Markings

Lens filter markings have been modernised for clarity:

• UV filters: Now marked as U1.2 to U4
• Sunglare filters: Marked as G0 to G4
• Infrared filters: Marked as R1.2 to R10
• Welding filters: Marked as W1.2 to W10

Optional L marking indicates compliance with colour recognition for signalling lights.

4. New Optional Features

EN ISO 16321 introduces several new optional safety features, including:

• High mass impact (HM)
• Chemical resistance (CH)
• Protection against radiant heat (7)
• Use in explosive atmospheres

These join existing features like anti-fog (N), scratch resistance (K), and protection against dust, liquids, and gases.

5. More Comprehensive Testing

The new standard includes updated test methods under EN ISO 18526, covering:

• Optical and physical properties
• Mechanical strength
• Headform compatibility
• Filter performance

The transition to EN ISO 16321 is more than a regulatory update, it’s a leap forward in ensuring better, more inclusive, and globally consistent eye protection. By understanding the changes and preparing early, you can ensure your workplace remains compliant and your team stays safe.