All optical products carry the CE mark indicating compliance with the relevant European Standard EN166. This standard tests for: impact, optical quality, chemical, dust and molten metal protection.
S - 22mm ball at 5.1m/s (11mph)
F - 6mm ball at 45 m/s (101mph)
B - 6mm ball at 120 m/s (268mph)
1 - Optical quality
3 - Liquids
4 - Large dust particles
9 - Molten metal and hot solids
K - Anti-scratch
N - Anti-fog
T - Extreme temperature
Equipment for eye and face protection during welding and allied processes.
Specifies materials, design, performance requirements, test methods and marking requirements for mesh eye and face protectors.
S - basic robustness
F - high speed particles, low energy impact
B - high speed particles, medium energy impact
A - high speed particles, high energy impact
If the symbols F, B and A are not common to both the mesh, the additional or alternative occular and the frame then it is the lower level which shall be assigned to the complete mesh eye and face protector.