Protective measures against natural optical radiation

Photograph of a yellow parasol under a blue sky

Source: grafxart - stock.adobe.com

Solar radiation has positive properties for the human body. Excessive exposure, however, may have serious and long-term consequences: in the worst-case scenario, exposure over the course of a lifetime may lead to skin cancer.

This risk can be reduced effectively by simple protective measures. However, it must be emphasised that the protective measures listed here provide protection against ultraviolet (UV) radiation not only during occupational activities; in order to reduce the risk of skin cancer significantly, these measures can - and should - also be taken during leisure time activities.

If a risk assessment reveals that persons working outdoors face an increased risk due to intensive UV exposure, protective measures must be taken in accordance with the TOP principle. This means that technical measures always take precedence over organisational and personal measures. If necessary, however, a combination of different measures may be used. Since work involving high UV exposure is often accompanied by high outdoor temperatures, consideration must be given at the same time to protection against heat.

As a first indication of whether outdoor work involves intense exposure to solar UV radiation, Occupational health rule AMR 13.3 provides a definition of “intense exposure to solar UV radiation.”


  • Technical measures

    These include the provision of shade, e.g. by:

    • Canopies
    • Parasols, awnings
    • Enclosed vehicle cabs
  • Organizational measures

    These measures are intended to reduce the time spent outdoors:

    • Avoiding spending time in the sun around midday (approx. 11 am - 3 pm)
    • Relocating activities to shaded or indoor areas, if possible, particularly during breaksIf
    • Avoiding overtime when the UV index (UVI) is high (> 6)
    • Restructuring of work processes; sharing work between several employees if appropriate
    • Instructing workers on possible hazards and protective measures
  • Personal measures
    Photograph of two employees wearing sunglasses and protective clothing

    Sunglasses, long clothing and headgear covering the back of the neck, for protecting workers who work outdoors frequently and for long periods
     Source: Wolfgang Bellwinkel/DGUV

    • Suitable (long-sleeved) clothing covering the whole body, with adequate UV protection (Ultraviolet protection factor, UPF)
    • Suitable headgear (with protection for the back of the neck if appropriate)
    • UV protective glasses or sunglasses that meet the requirements for sun glare filters for industrial use in accordance with EN 172
    • Use of suitable sunscreen with a sufficiently high sun protection factor (at least SPF 30; better: 50+), for all parts of the body not covered by clothing

  • UV Index

    The UV index describes the anticipated daily peak value at ground level of sunburn-inducing UV radiation. The UV index was developed to provide a tangible tool, easy to use in the field, for quantifying the risk posed by UV radiation. It is therefore eminently suitable for raising awareness of UV-induced skin cancer and preventing it.

    Table showing the “traffic-light” system: if the UV index is low (green), no measures are required. Successively greater measures are required at medium, high and very high index values.

    UV index and recommended protective measures.
     Source: BG BAU

    The IFA is part of the UV monitoring network of the German Federal Office for Radiation Protection (BfS), with a measuring station of its own in Sankt Augustin. Progressions of the UV index, updated daily, can be viewed at the station.


One area of activity of the IFA's Section Optical Radiation is examining and assessing the suitability of measures for protection against exposure to optical radiation. The analysed information is published online to give guidance and raise awareness for the selection of different types of suitable protection.

IFA Project 4208 examined the UV radiation transmission of vehicle windows. The results of this study can be found in the information sheet: Focus on IFA's work No 0387.

Photograph of a truck with a measuring instrument fitted to the window

Measuring the transmission properties of truck windows
 Source: IFA

Further projects examined the transmission properties of UV protective clothing and the suitability of wearable devices as UV warning systems with focus on occupational settings (see Wearable UV sensors for use during work performed outdoors, in: Focus on IFA’s work, No 0442). A test specification is currently being implemented for sunscreen products, which are to be tested and assessed for their suitability for usage in an occupational context.


Information on Heat and Climate Change

Competence Centre for Climate Change and Occupational Safety and Health (KKA) at the IFA

Recommendations for a safe, healthy climate at work
Info page of the BAuA on Workplace Climate