and clean rooms via a mobile or centralized system with
handheld, drop-down or low pressure sprayers [20]. Greene [22] compared the effectiveness as
disinfectants of ozonated water and a chlorinated sanitizer. Stainless steel plates were incubated in
UHT-pasteurised milk inoculated with pure cultures of either Pseudomonas fluorescens or
Alcaligenes faecalis. The method was designed to simulate the formation of a biofilm containing
these bacteria. The active component of the chlorine-based commercial product employed in the
experiments was sodium dichloro-s-triazinetrione. The product was applied for a 2 min contact time
as specifically recommended by the manufacturer for dairy industry surfaces. The water employed
contained 0.5 ppm ozone and was applied for 10 min in each treatment. As the following table
shows, the treatments were equally effective in inhibiting both microorganisms, with both treatments
destroying over 99% of those present.