UV Sterilization: Effectiveness Against Bacteria & Parasites

Ultraviolet (UV) light is a clean and safe alternative to chlorine and sodium hypochlorite, which are used widely for bacteria sterilization. While it is proving to be a promising technology, its uses are still limited.

Exposure

• The exposure time for sterilization by UV light varies. Vibrio parahaemolyticus is 100 percent sterilized over 10 minutes, while E. coli requires 30 minutes of exposure.

Resistance

• While no bacteria develop resistant strains to UV emissions, some parasites such as cryptosporidium and giardia do not respond to UV treatment.

Sterilization

• UV light does not kill bacteria. It sterilizes them. Bacteria sensitive to UV rays are not able to reproduce after treatment.

Proximity

• Effective UV sterilization requires the bacteria be close to the emission source. The cited study used a lamp source set 20mm (just under an inch) from the subject organisms.

Industrial Application

• Due to the limited range of exposure and unproven results with parasitic organisms, UV sterilization is limited to smaller industrial applications as the technology is developed.