Action spectrum of Bacillus subtilis spores for validation of polychromatic ultraviolet (UV) systems.

In Germany, UV treatment systems for municipal drinking water must be validated and certified prior to implementation. This applies to systems using both low- and medium-pressure mercury discharge lamps (LP and MP lamps). To evaluate germicidal efficacy of the systems and define operational ranges, full-scale biodosimetry is carried out by an accredited laboratory using a non-pathogenic surrogate microbes.