UV3W-LED.docx
Page 7 of 17
© UV Light Technology Limited - Issue No: 3/12
Operating Instructions for UV 3W LED
Some people may be unusually photosensitive, exposed to photosensitising agents,
aphakic (had an eye lens removed and not replaced by an artificial lens) or
pseudophakic (had an eye lens replaced with a non UV light absorbing artificial
intraocular lens) in which case these exposure limits may not provide adequate
protection.
The UV light exposure limits – within an 8 hour period per day are as follows:
UV light in the spectral region 180nm-400nm (UV-A, UV-B and UV-C)
maximum permissible effective radiant exposure for
the unprotected skin and eye = 30 J/m
2
eff
UV light in the spectral region 315nm-400nm (UV-A)
maximum permissible radiant exposure for
the unprotected eye = 10,000 J/m
2
It is necessary for duty holders to limit personal UV light exposure time at the
specified distances in the Table on page 5 (hazard values), to ensure that the
maximum permissible exposure values for the unprotected skin and eye are
NOT
EXCEEDED
within an 8 hour period per day.
The exposure limit values are derived from the ICNIRP guidelines which are based on
maximum permissible exposure values for an 8 hour working day and take into
account the daily 24 hour light/dark cycle where cellular repair can take place after the
exposure is discontinued. Therefore, in cases where continuous exposure for longer
than 8 hours is possible, for example 10-12 hour extended shifts or even double
shifts, special care needs to be taken.
The distance at which the maximum permissible UV light exposure time is equal to 8
hours is known as the Hazard Distance (HD). At this distance and beyond, the
applicable exposure limit value cannot be exceeded.
If the maximum permissible exposure values are exceeded then the UV light
irradiance must be reduced by appropriate control measures. These could include
containment, moving further away from the UV light source, reducing exposure time,
or as a last resort provision of personal protective equipment (PPE).
