Commercial, The radiation from ultraviolet light at 2537 angstroms provided inside the Lifegard Ultraviolet Sterilizer exerts a lethal effect on micro-organisms. UV light alters genetic material within the cells, which interrupts respiration. UV light, when used properly, is extremely beneficial in destroying disease causing pathogens as they pass through the unit. UV sterilization is an effective method of disease control. Four major factors affect the percent kill of free-floating micro- organisms by UV radiation.