CIE 187:2010 PDF Download

The CIE 187:2010 standard addresses the potential risks associated with the use of UV-C energy for air disinfection purposes. UV-C radiation, with a wavelength range of 100 nm to 280 nm, is commonly used in low-pressure mercury lamps to eliminate airborne pathogens in various environments. However, in settings where direct exposure of the room air is required above the heads of occupants, there is a possibility of human exposure to reflected or scattered UV-C radiation.

The standard highlights the known side effects of overexposure to UV-C radiation, which include transient corneal and conjunctival irritation (photo-keratoconjunctivitis) and skin irritation (erythema). These effects typically resolve within a 24 to 48-hour period and are not known to cause lasting biological damage. The standard further mentions that well-engineered UV-C systems should meet the threshold limit for continuous exposure to UV-C radiation set by organizations such as the ACGIH and ICNIRP (6 mJ*cm-2 or 60 J*m-2 over 8 hours).

While there have been incidents of accidental UV-C overexposures due to poor installations, the standard emphasizes that UV germicidal irradiation can be safely used for upper air disinfection without a significant risk of long-term delayed effects such as skin cancer. This is due to the attenuation provided by the stratum corneum and epithelial tissues of the skin, which greatly reduce the risk relative to UV-B radiation.