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UVCS LED Light-Curing Conveyor Systems User Guide
Figure 1. Light Spectrum
The strictest interpr
etation of the TLV (over the UVA range) for workers’ eyes and skin is 1 mW/cm
2
(intensity),
continuous exposure. Unless workers are placing bare hands into the curing area, it is unusual to exceed these
limits. To put 1 mW/cm
2
limit into perspective, cloudless summer days in Connecticut regularly exceed
3 mW/cm
2
of UVA light and also include the more dangerous UVB light (primarily responsible for suntans, sun
burns, and skin cancer) as well.
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 two ways to protect operators from UV
exposure: shield the operator and/or shield the source.
Shield the Operator
UV-Blocking Eye Protection - UV-blocking eye protection is recommended when operating UV light-curing
systems. Both clear and tinted UV-blocking eye protection is available from Dymax.
UV-Blocking Skin Protection
Where the potential exists for UV exposure upon skin, opaque, UV-blocking clothing, gloves, and full-face
shields are recommended.
Shield the Source of UV
Any substrate that blocks UV light can be used as a shield to protect workers from stray UV light. The following
materials can be used to create simple shielding structures:
Rigid Plastic Film
—
Transparent or translucent/UV-blocking plastics (typically polycarbonate or acrylic) are
commonly used to create shielding where some level of transparency is also desired.
