A comparison of pulsed and continuous ultraviolet light sources for the decontamination of surfaces

The experimental results on the development of a decontamination process th at uses ultraviolet light and chemical photosensitizer for disinfecting sur faces and solutions are reported. Reduction in the microbial viability as a function of applied UV fluence is presented for the inactivation of Bacill us subtilis spores. Results obtained with aqueous solutions and with surfac es indicate that pulsed UV light is more effective than continuous UV light . Nearly three orders of magnitude of enhanced inactivation have been achie ved with the photosensitized UV process on surfaces.