The European standard DIN EN 166 describes all personal eye protection requirements in general. Safety glasses in accordance with DIN EN 166 consist of a frame and lenses, which are classified in the following standards into safety lenses and lenses with a filter effect.

Labelling in accordance with DIN EN 166:  Technical information on safety eyewear lenses are given in the following order in accordance with EN 166: 

  • protection class (filters only)
  • manufacturer mark
  • optical class (except for ancillary lenses)
  • certification mark (if applicable)
  • symbol for mechanical strength
  • symbol for non-adherence of molten metal

DIN EN 169 – Filters for welding and related techniques

In relation to special product requirements for eye protection, the EN 169 standard defines protection levels and transmittance requirements for lens filters intended to protect employees during:

  • light flame cutting
  • hard soldering
  • welding
  • arc gouging
  • plasma cutting

Labelling and protection levels for welding filters in accordance with standard EN 169

Welding filters must be permanently marked on the edge. The first number refers to the protection class of the safety eyewear. Depending on the procedure, higher electrical currents require higher protection classes in accordance with DIN EN 169. 

DIN EN 170 – Ultraviolet filters

As part of the standards for special product requirements, standard DIN EN 170 defines the protection levels and transmittance requirements for ultraviolet filters. If the lens of the eye is exposed to ultraviolet light for too long, it can lose its transparency, potentially leading to visual impairment or vision loss. Safety eyewear lenses in accordance with EN 170 therefore meet performance requirements to protect the eye from ultraviolet radiation during hazardous activities.  Unlike welding filters in accordance with EN 169, the UV filters are not suitable for looking at electrical arcs, either directly or indirectly.