BlueWave® QX4® User Guide
6
UV Exposure
Figure 1. UV Spectrum
Standard Dymax UV light-curing systems have been designed primarily to emit UVA and
Visible energy (Figure 1). Depending on the type of LED head used, the energy emitted
from the
BlueWave QX4
can either be in the upper end of the UVA portion of the
spectrum (PrimeCure® & RediCure®) or in the lower portion of the visible spectrum
(VisiCure
™
). UVA energy is generally considered the safest of the three UV ranges: UVA,
UVB, and UVC. Although OSHA does not currently regulate UV-light exposure in the
workplace, the American Conference of Governmental Industrial Hygienists (ACGIH)
does recommend Threshold Limit Values (TLVs) for ultraviolet light.
The strictest interpretation of the TLV (over the UVA range) for workers’ eyes and skin
allows continuous exposure up to 1 mW/cm
2
(intensity). Unless you are placing bare
hands into the curing area, it is unusual to exceed these limits. To put 1 mW/cm
2
limit
into perspective, a cloudless summer day will typically exceed 3 mW/cm
2
of UVA light,
and also include the more dangerous UVB light (primarily responsible for sun tans, sun
burns, and skin cancer).
Checking the Workstation
The human eye cannot detect "pure" UV light, only visible light. A radiometer should be
used to measure stray UV light to confirm the safety of a UV light-curing process. A
workstation that exposes an operator to more than 1 mW/cm
2
of UVA continuously
should be redesigned.
Protecting Operators
Light-curing technology can be a regulatory compliant, "worker-friendly" manufacturing
process when the proper safety equipment and operator training is utilized. There are
