Protecting Workers from Ultraviolet Radiation - icnirp

Protecting Workers from Ultraviolet Radiation
• avoid unnecessary additional elective UV exposure, as from sunbed use.
When these measures are used properly and in combination, it is possible to reduce exposure to
solar UVR to within acceptable levels without seriously limiting the range of outdoor activities
that can be safely pursued. Protective measures should be adequate but consistent with the type
of work being conducted and not impair the efficiency of the work or cause additional hazards.
Whilst protection of the eye is essential for all races, skin protection is much more important for
workers with sun-sensitive (melano-compromised) skin (Table 2). The following guidance for
skin protection is therefore critical for the latter category of workers.
9.1 Engineering Controls and Shade
Shade can be provided naturally by trees, by utilizing canopies and semi-permanent structures, or
by constructed shade in areas where large numbers of workers may gather. It is important that
the shade structure used blocks the line-of-sight path from most of the sky, as well as that from
the solar disc. At least half of the total (“global”) solar UVR is received from the sky, as a result
of scattering by the atmosphere. An even greater fraction is skylight (“diffuse” component of
sunlight) under cloudy or hazy conditions or when the solar zenith angle is greater. At lower
latitudes, the contribution from the sky is smaller than that from the solar disc, but is never
insignificant. This effect is more pronounced for UVR than visible radiation, so that observing
the amount of shade provided by a structure at visible wavelengths provides an over-estimate of
its UVR protective properties. Small shade structures that leave large amounts of sky visible will
provide only limited UVR protection; this protection may be sufficient for those workers
outdoors for 1-2 h or less. An example of practical use of shade is the addition of an awning to
workers on a scaffold. Canopies or cabs on earth-moving equipment and farm tractors can
provide substantial protection. Since glass strongly attenuates UVB and some shorter
wavelengths of UVA, glass enclosures, windows in automobiles, trucks and the cabs of tractors
and earth-moving equipment can provide substantial protection; hence, if such equipment can be
operated with windows up, greater protection can be afforded. Some vehicle windows, such as
windscreens have a shatter-proof laminate that contains a UVB absorber, with the result that
UVA radiation in blocked as well.
Materials that are visibly clear will absorb UVR to varying degrees. For example, window glass
transmits some radiation down to 310nm (within the UVB), whereas most plastics such as
polymethyl-methacralite (e.g., Perspex® or Lucite®) and polycarbonate normally do not
transmit below about 370 nm. In general windscreens (windshields) on cars block both UVA and
UVB (Sliney 1994). Cockpit windscreens on airplanes block UVB and UVA (Diffey and
Roscoe 1990).
9.2 Administrative Controls
9.2.1 Educational Programs: Training and Awareness
Training programs must be tailored to local circumstances. A program for outdoor workers in
the tropics would not be appropriate for workers in more temperate zones. The nature of the
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