UV Hazard Calculator
UV hazard assessment with the ICNIRP/ACGIH actinic weighting function S(λ) and the UVA eye limit. Covers 180–400 nm.
Educational only — not compliance-grade
These pages implement the published exposure limits for the cases each one states, but they are educational tools: no laser safety officer has signed them off.
- Do not use these results alone for PPE selection, NHZ / NOHD approval, controlled-area sign-off, enclosure/interlock approval, or formal classification.
- Always verify against ANSI Z136.1, IEC 60825-1, your local procedures, and the responsible laser safety officer / CLSO.
S(λ) Weight
0.500
Effective Irradiance
5.00e-3 W/cm²
Max Safe Time
0.60 s
Hazard Ratio
48000.000
Limits for the eye within 8 h (ICNIRP 2004): S(λ)-weighted exposure ≤ 3 mJ/cm², and unweighted 315–400 nm exposure ≤ 1 J/cm². For a single wavelength, effective irradiance = irradiance × S(λ). Limited by: Actinic limit, 3 mJ/cm² S(λ)-weighted.
Model and references
Exact. The equations are exact within the stated assumptions, or are a standard's tabulated values. The results are as good as the inputs. About the tiers
Monochromatic source: S(λ)-weighted limit of 30 J/m² plus ICNIRP's unweighted UVA limit of 10⁴ J/m² (315–400 nm), within 8 h. ACGIH and IEC relax the UVA limit after 1000 s; ICNIRP, used here, does not.
- ICNIRP (2004). Guidelines on limits of exposure to ultraviolet radiation of wavelengths between 180 nm and 400 nm (incoherent optical radiation). Health Phys. 87(2), 171–186. Table 1 (S(λ) and the exposure limits). doi:10.1097/00004032-200408000-00006
- IEC 62471:2006. Table 4.1 (the same S(λ) values).