Eyewear standards, frame marking & lens marking
UV and the effects on the eye
When protecting the eyes it is important to select the correct type of lens filter. Clear polycarbonate lenses offer protection at the lower (UV215 to 380NM) range, whilst a filter conforming to EN172 offers additional protection through to 780NM.
Standards
- EN170 – Recommended during high UV radiation
- EN166 – Guaranteed minimum resistance of the protective eyewear against everyday risks including dropping the protective eyewear onto the ground, ageing by light exposure, exposure to heat or corrosion etc.
Frame marking
Frame marking must include the CE Symbol and manufacturer’s name (logo or brand). If the glasses refer to the EN standard, the EN standard number is mandatory together with the various use and mechanical strength symbols, in accordance with the tests requested by the manufacturer.
Mechanical strength symbols:
- B. Medium energy impact, resists a 6mm, 0.86g ball at 120m/s
- S. Extra strong, resists a 22mm, 43g ball falling 1.3m
- T. The letter T, immediately after the mechanical strength symbol, authorises use for high speed particles at extreme temperatures
Use symbols:
- 3. Liquid droplets or splashes
- 4. Large dust particles > 5 microns
- 5. Gas and fine dust particles < 5 microns
- 9. Molten metal and hot solids
Lens marking
Lens marking must include the scale number for filtering lenses and the manufacturer’s name (logo or brand recommended by the manufacturer).
Mechanical strength symbols:
- B. Medium energy impact, resists a 6mm, 0.86g ball at 120m/s
- T. The letter T, immediately after the mechanical strength symbol, authorises use for high speed particles at extreme temperatures
- F. Low energy impact, resists a 6mm, 0.86g ball at 45m/s
- S. Extra strong, resists a 22 mm 43g ball falling 1.3m at 5.1m/s
Optical class symbols:
1. Continuous work
Use symbols:
9. Molten metal and hot solids
Others symbols:
- K. Resistance to surface damage by fine particles (optional)
- N. Resistance to fogging (optional)
