Skin MPE and Hazard Calculator
ICNIRP 2013 skin exposure limit from 180 nm to 1 mm: the limit for your exposure time, the beam's irradiance over 3.5 mm and the largest safe power.
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.
Skin limit H
1.00e+5 J/m² (10.0 J/cm²)
As irradiance H/t
10000 W/m² (1.00 W/cm²)
Beam over 3.5 mm
64929 W/m² (6.49 W/cm²)
Max power for this time
151 mW
Power / max power
6.64× — exceeds the skin limit
Skin exposure limit from ICNIRP 2013 (Health Phys. 105:271, Table 7) for one exposure of 1 ns to 30 000 s. From 400 to 1400 nm: 200 C_A J/m² up to 100 ns, 1.1×10⁴ C_A t^0.25 J/m² up to 10 s, then 2 C_A kW/m², with C_A = 1 below 700 nm, rising to 5 at 1050 nm. In the UV and above 1400 nm the skin has the eye's corneal limit. Above 1400 nm and beyond 10 s, an exposed area over 0.01 m² (here the area inside the 1/e² diameter) lowers the CW limit from 1000 W/m² to 10/A W/m², and to 100 W/m² above 0.1 m². The beam is a round Gaussian averaged over a 3.5 mm aperture (11 mm from 100 µm). The max power is the largest that stays within the limit at every duration up to t; the tables' rounded joints can make it up to 2 % lower than the limit at t alone.
The skin limit across the spectrum for the chosen exposure time, and the beam's radiant exposure over the averaging aperture.
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
ICNIRP 2013 Table 7 skin limit, 1 ns – 30 ks, with the large-area rule above 1400 nm; round Gaussian beam averaged over 3.5 mm, or its peak if under 1 mm (1/e; Table 7 note b). Not modelled: pulse trains.
- ICNIRP (2013). Guidelines on limits of exposure to laser radiation of wavelengths between 180 nm and 1,000 µm. Health Phys. 105(3), 271–295. Tables 3, 5, 7 and 8. doi:10.1097/HP.0b013e3182983fd4