EN 166 - European standard for protective eyewear

EN166 is the European standard covering the requirements for protective eyewear. It applies to all eye protection and guarantees adequate marking and the quality of the equipment. The standard also defines the basic characteristics to which all eye protection must conform with regard to two criteria: optical quality and minimum mechanical strength. While all eye protection must be EN166 certified, filters and equipment are also covered by specific standards which must be understood in order to ensure protective equipment is adapted to the activity of its wearer.

EN 166

Standards for protection against artificial and natural radiation

EN170
EN171
EN172

Standards relative to welding work for equipment and against radiation

EN169
EN175
EN379

Standards relative to laser work

EN207
EN208

Mandatory Markings

Requirement Lens Symbol Frame Marketing
Scale Number or Shade Number Required for filters only -
Manufacturer’s Identification Required Required
Number of the Standard See below for explanation EN166
Optical Class 1, 2 or 3
Minimum Robustness No symbol No symbol
Enhanced Robustness S S
Low Energy Impact F F
Medium Energy Impact B B
High Energy Impact A A

Particular / Optional Markings

Requirement Lens Symbol Frame Marketing
Droplets or splashes of liquids 3 3
Large dust particle 4 4
Gas and fine dust particle 5 5
Short circuit electric arc 8 8
Molten metals and hot solids 9 9
Resistance to surface damage by fine particles K
Resistance to fogging N

Marking for standards numbers

  • EN170
    • 2: UV filter, color recognition may be affected
    • 2C: UV filter with good color recognition
  • EN171
    • 4: IR protection
  • EN172
    • 5: Solar filter without infrared protection
    • 6: Solar filter with infrared protection