For decades, EN 166 has been the benchmark European standard for workplace eye protection. From construction sites and manufacturing facilities to engineering workshops and warehouses, millions of workers have relied on safety spectacles and goggles certified to EN 166.
However, the industry is now transitioning to EN ISO 16321-1:2022, a new international standard that modernises eye and face protection requirements while creating greater consistency across global markets.
The introduction of EN ISO 16321 has caused some confusion, with many safety managers and PPE buyers asking:
- Is EN 166 still compliant?
- Do we need to replace existing safety eyewear?
- What has changed under the new standard?
The good news is that EN 166 has not become immediately become obsolete. Existing EN 166 certified products remain compliant during the transition period, and organisations do not need to replace suitable eye protection overnight.
In this guide, we will explain the differences between the two standards, what the new classifications mean, and how businesses can prepare for the ongoing transition.
Is EN 166 Still Compliant?
One of the most common misconceptions surrounding the introduction of EN ISO 16321 is that EN 166 certified safety glasses are no longer compliant.
This is not the case.
The transition to EN ISO 16321 has been designed to allow manufacturers, distributors and end users sufficient time to adapt to the new requirements.
The Transition Timeline
- EN ISO 16321-1:2022 was published as the new international standard for occupational eye and face protection.
- The transition period for manufacturers and PPE suppliers began in November 2025.
- Manufacturers are gradually re-testing and certifying products to the new standard.
- EN 166 certified products can continue to be sold and used throughout the transition period (up to a maximum of 5 years from their issue date).
- Businesses purchasing new safety eyewear will increasingly see products certified to EN ISO 16321 appearing across product ranges.
For employers, this means there is no immediate requirement to replace compliant safety eyewear that continues to provide appropriate protection for workplace hazards.
Why Was EN ISO 16321 Introduced?
According to guidance from leading safety eyewear manufacturers including our trusted suppliers, UVEX and Bollé Safety, the new standard was introduced to address changing workplace risks and create more consistent international requirements.
Key objectives include:
- Improved global harmonisation of eye protection standards
- Greater clarity in product markings
- Enhanced testing procedures
- Better classification of workplace hazards
- Easier product selection for safety managers and end users
Rather than completely changing how safety eyewear works, EN ISO 16321 builds on the foundations established by EN 166 while introducing a more modern and structured framework.
Understanding the New Markings
One of the biggest changes under EN ISO 16321 is the updated marking system.
While EN 166 users became familiar with markings such as F, B and A for impact resistance, the new standard introduces more detailed identification codes that provide additional information regarding:
Mechanical Protection: Clearer identification of impact resistance performance.
Environmental Condition: Protection suitability for extreme temperatures and workplace environments.
Solar Protection: Enhanced classification of products designed to reduce glare and sunlight exposure.
Specific Workplace Hazards: More detailed information regarding the intended application of the eyewear.
For PPE purchasers, these changes help ensure the correct product is selected based on workplace risk assessments.
Need Help Choosing Compliant Eye Protection?
Explore our safety eyewear range today or get in touch with our team to find the right protective eyewear solution for your workforce.