UV dose at the workplace — EU-wide harmonised; the country only decides the enforcement authority.
UV band
Scenario
① Daily dose · 8 h shift
Effective exposure H_eff
30J/m²
Highest erythema and keratitis effectiveness; classic industrial UV-C case
② Maximum irradiance
Effective irradiance E_eff
~ 1mW/m²
For 8 h of continuous exposure · see the reciprocity table for other times
Reciprocity · H = E × t
Exposure time
Max. permitted E_eff
Field example
1 second
30.0 W/m²
Quick glance through an open maintenance hatch
10 seconds
3.0 W/m²
Brief service action with the source on
1 minute
500.00 mW/m²
Short walk-through without PPE
10 minutes
50.00 mW/m²
Cleaning task nearby
1 hour
8.33 mW/m²
Extended stay in the area around the system
8 h (day shift)
1.04 mW/m²
Continuous workplace next to the system — practically only achievable with shielding
Field reality at UV-C 254 nm A 36 W low-pressure Hg lamp at 1 m distance typically produces ~1 W/m² E_eff.
At that irradiance the maximum permitted exposure time is 30 s.
8 h continuous requires a factor-1000 shielding.
UV intensity × distance · service and installation sizing
I = I₀ / r²
Irradiance E_eff
1.00W/m²
Reference: 1 W/m² bei 1 m
Reduction vs. reference
100.0 %vs. 1 m
Max exposure time
30seconds
= ICNIRP 30 J/m² ÷ aktuelle E_eff
Distance1.0 m
Source type
Practice: At 1.0 m distance you reach ~100 % of the reference intensity.
Double to 2.0 m → only ~25 %. Distance is the most powerful protective lever.
Mandatory protective measures (DE)
Interlock against unauthorised opening during operation
Viewing window with UV-blocking glass (UV-block PMMA or specially filtered)
Warning sign "UV radiation" + operating instructions per OStrV
Annual instruction of employees (DGUV-I 203-039)
Documented risk assessment (BAuA / DGUV template)
Country · enforcement
Enforcement & escalation in DE
These authorities are responsible for your worker-safety path.