What standard regulates safety glasses? Complete guide to EN 166.

Every year, thousands of workplace accidents in Europe affect workers' eyesight due to particle impacts, chemical splashes, or radiation. The good news is that there is specific legislation regulating the design, manufacture, and performance of this Personal Protective Equipment (PPE): the EN 166 standard.

If you work in construction, metallurgy, laboratories, or any sector with eye hazards, knowing this standard is not optional: it is the guarantee that the glasses you buy truly protect and comply with the CE marking required by European legislation.

In this article, we explain what the EN 166 regulates, how to identify it in a product, and which glasses to choose according to your activity.

WHAT DOES THE EN 166 STANDARD ESTABLISH?

The EN 166 is the European reference standard for personal eye protection. It defines the general requirements that all eye protectors (full-frame glasses, side-shield glasses, and face shields) used in the workplace must meet, regardless of the specific risk they protect against.

Requirements covered by EN 166

• Optical quality: classified into classes 1, 2, or 3, depending on the allowed visual distortion. Class 1 allows continuous use throughout the workday.

• Mechanical resistance: impact tests at different speeds (from low-energy impact to high-speed impact).

• Robustness and resistance to aging: durability against continuous use, corrosion, and flammability.

• Field of vision: absence of optical defects that could impair the worker's visual perception.

• Mandatory marking: each lens and frame must be marked with the manufacturer, optical class, mechanical resistance symbol, and reference to the standard.

Complementary standards for safety glasses according to risk

The EN 166 is the foundation upon which specific standards are based according to the type of exposure:

An evolving standard

It is worth noting that there is already an update in development: the EN ISO 16321-1, which will gradually replace the EN 166 in the future and introduces facial fit tests with multiple anthropometric models, as well as a stricter integration of UV and IR protection. Staying informed about this transition is key for any PPE purchasing manager.

WHEN ARE EN 166 CERTIFIED GLASSES USED?

Glasses certified under this standard are mandatory in activities where there is a risk of particle projection, splashes, or radiation. The most common sectors and tasks are:

• Construction and civil works: cutting, drilling, using power tools.

• Metallurgy industry: welding, grinding, machining.

• Chemical sector and laboratories: handling corrosive substances or liquid splashes.

• Carpentry and woodworking: projection of chips and dust.

• Industrial maintenance and logistics warehouses: risk of impact from suspended particles.

At Sekureco, you will find EN 166 certified glasses classified by type of risk, so you can choose the exact protection your job requires.

EN 166 certified products at Sekureco

Some highlighted categories within our catalog:

• Full-frame glasses (panoramic type): ideal for environments with dust, gases, or chemical splashes.

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• Ventilated sports-style glasses: lightweight and comfortable, recommended for long days in construction or warehouses.

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• Glasses with UV/IR filter (EN 170/171) 3M: essential for work with intense solar radiation or heat processes.

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• Welding glasses (EN 175): provide complete face and eye protection during welding tasks.

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QUESTIONS ABOUT SAFETY GLASSES AND EN 166

1. Is the CE marking mandatory on safety glasses? 

Yes. All eye protection PPE marketed in the EU must bear the CE marking, which certifies its compliance with Regulation (EU) 2016/425 and the corresponding harmonized standards, such as EN 166.

2. What is the difference between EN 166 glasses and regular sunglasses? 

Regular sunglasses are not designed or certified to withstand impacts or meet PPE requirements. Only glasses with the EN 166 marking guarantee certified mechanical protection.

3. Can I use prescription glasses certified EN 166? 

Yes, there are models of safety glasses that are prescription or designed to be worn over corrective glasses, as long as they meet the same resistance and identification requirements.

4. How often should protective glasses be replaced? 

There is no universal fixed timeframe; it depends on wear, lens scratching, and the manufacturer's instructions. Regular visual inspection and replacement at any sign of deterioration are recommended.

5. Will EN 166 disappear?

 It will gradually be replaced by EN ISO 16321-1, although during the transition period, both regulations may coexist according to the implementation schedule.

PROTECT YOUR EYES WITH THE RIGHT CERTIFICATION 

Choosing certified safety glasses is not a formality: it is the difference between real protection and a false sense of security. At Sekureco, you will find a selection of EN 166 certified eye protection glasses, with different optical classes and filters according to your professional activity.

Discover our catalog of certified safety glasses and equip your team with the eye protection required by European regulations.