A Need to Revise Human Exposure Limits for Ultraviolet UV-C Radiation^†.

Area of Science:

• Environmental Health
• Photobiology
• Public Health

Background:

• The COVID-19 pandemic increased interest in UVGI for indoor air disinfection.
• Safe installation of UV-C lamps is a significant challenge for UVGI implementation.
• Current exposure limits for UV-C radiation (180-280 nm) may be overly conservative.

Purpose of the Study:

• To review the scientific basis for existing UV-C exposure limits.
• To propose adjustments to UV-C exposure limits for enhanced safety.
• To differentiate safety limits for skin and eye exposure to UV-C radiation.

Main Methods:

• Literature review of UVGI safety and exposure limits.
• Analysis of UV-C spectral bands and their biological effects.
• Development of revised exposure limit recommendations.

Main Results:

• Current UV-C exposure limits require reassessment.
• Proposed adjustments include separate limits for skin and eyes below 300 nm.
• Increased exposure limits are suggested for UV-C below 250 nm.

Conclusions:

• Adjusted UV-C exposure limits can enhance the safe application of UVGI.
• Revised limits will facilitate wider adoption of UVGI in public and medical settings.
• Further research into UV-C dosimetry and biological effects is warranted.