EN 166 2001

Eye Protection Standard

The EN 166 standard defines the requirements for personal eye protection. Safety eyewear compliant with this standard consists of frames and lenses, which are classified based on optical performance, mechanical strength, and protection against hazards. It applies to all types of protective eyewear, including safety glasses, goggles, and face shields.

Protective Properties

Each EN 166-compliant lens or frame displays key markings:

  • Protection Class (for filtering lenses)

  • Manufacturer’s mark

  • Optical Class (except for ancillary lenses)

  • Certification mark (if applicable)

  • Symbols indicating mechanical strength and resistance to molten metal

Standards Referenced

  • EN 166 – Specifications for personal eye protection

  • EN 167 – Optical test methods

  • EN 168 – Non-optical test methods

Frame Marking

Frames must include the CE marking, the manufacturer’s name, logo or brand, the EN standard number, and relevant use and mechanical strength symbols.

Use Symbols:

  • 1 – Protection against liquid droplets or splashes

  • 2 – Protection against large dust particles (>5 microns)

  • 3 – Protection against gas and fine dust particles (<5 microns)

  • 4 – Protection against electrical short circuit arcs

  • 5 – Protection against molten metal and hot solids

Mechanical Strength Symbols:

  • S – Extra strong, resists a 22 mm, 43 g ball falling from 1.3 m

  • F – Low energy impact, resists a 6 mm, 0.86 g ball at 45 m/s

  • B – Medium energy impact, resists a 6 mm, 0.86 g ball at 120 m/s

  • A – High energy impact, resists a 6 mm, 0.86 g ball at 190 m/s

Lens Marking

Lenses must include the scale number for filtering lenses and the manufacturer’s name or logo.

Optical Class:

  • 1 – Suitable for continuous work

  • 2 – Suitable for intermittent work

  • 3 – Suitable for occasional work (not for continuous use)

Mechanical Strength Symbols:

  • S – Extra strong, resists 22 mm, 43 g ball falling from 1.3 m at 5.1 m/s

  • F – Low energy impact, resists 6 mm, 0.86 g ball at 45 m/s

  • B – Medium energy impact, resists 6 mm, 0.86 g ball at 120 m/s

  • A – High energy impact, resists 6 mm, 0.86 g ball at 190 m/s

  • K – Resistance to surface damage by fine particles (optional)

  • N – Resistance to fogging (optional)

  • T – Authorised for use with high-speed particles at extreme temperatures (optional)