The development of photosensitized pulsed and continuous ultraviolet decontamination techniques for surfaces and solutions

The experimental results of a decontamination process that uses an ultraviolet (UV) light and a chemical photosensitizer for disinfecting surfaces and solutions are reported. Reduction in the microbial viability as a function of applied UV fluence and initial photosensitizer concentration is presented for the inactivation of both the vegetative and spore forms of Bacillus subtilis niger. Encouraging results have been obtained with both aqueous solutions and surfaces; and with both continuous and pulsed UV light sources. Extrapolation of the results and an estimate of the process speed and efficiency permit a comparison with other decontamination methods.