ONORM EN 170 : 2003

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Designation and identification
5 Requirements
   5.1 General
   5.2 Transmittance requirements
   5.3 Ocular with enhanced colour recognition (optional)
Annex A (normative) Relative visual attenuation quotient
        for signal light recognition
Annex B (informative) Guidance on selection and use
Annex C (informative) Uncertainty of measurement and results
        interpretation
Annex ZA (informative) Clauses of this European Standard
         addressing essential requirements or other provisions
         of EU Directives
Bibliography

Defines the transmittance requirements and the scale numbers for filters for protection against ultraviolet radiation. EN 166 gives other applicable requirements for these types of filters. Annex A gives advice on the selection and use of these filters.