EN 166 - 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.
Standard EN166 also defines the basic characteristics to which all eye protection must conform with regard to two criteria: the optical quality and the minimum strength. While all eye protection must be EN166 certified, all 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.
Scale Number or Shade Number
Required for filters only
Number of the Standard
See below for further explanation
If high-speed particle testing requirements are met, the S symbol is replaced by one of the symbols below.
Low Energy Impact
Medium Energy Impact
High Energy Impact
Droplets or splashes of liquids
Large dust particle
Gas and fine dust particle
Short circuit electric arc
Molten metals and hot solids
Resistance to surface damage by fine particles
Resistance to fogging
Marking for standards' numbers
2: UV filter, color recognition may be affected.
2C: UV filter with good color recognition.
4: IR protection
5: Solar filter without infrared protection.
6: Solar filter with infrared protection.