Background Clean-In-Place (CIP) systems are closed processes in which a recirculation cleaning solution is used to disinfect food-processing plants. Though these cleaning and disinfection methods are essential for maintaining hygienic conditions, they have significant environmental impacts, particularly high water consumption and production of highly-polluted effluents. Hazardous by-products from disinfection are a further serious environmental consideration. Objectives The OZONECIP project sought to develop approaches that would lead to a reduction in the environmental impact of cleaning operations in food-processing plants. The project aimed to demonstrate an innovative, environmentally-friendly and efficient technique using ozone as an alternative cleaning agent. CIP is already considered a Best Available Technique (BAT) by the European reference documents (BREFs). However, the ‘Ozone CIP’ technique goes beyond the current BAT. Ozone is a highly efficient antimicrobial agent which leaves no residues, because it breaks down into oxygen after being used for disinfection. The new technique should result in significant water savings and improvements in wastewater quality. Results The OZONECIP project fulfilled the expectations of it as detailed in the project proposal: that it would contribute to the reduction of the environmental impact of sanitation operations in the food industry through use of an innovative sanitation technique, based on the use of ozone. A pilot ozone CIP system was constructed to simulate conventional cleaning protocols based on the use of ozonated water. The demonstration activities focused on brewery, winery and dairy sector conditions, and the results were very satisfactory, with the ozone as a cleaning agent leading to the following results: Up to 50 percent water savings per cleaning cycle compared to conventional cycles; Up to 50 percent reduction in organic load in wastewater, in terms of weight per cleaning cycle, compared to traditional cycles. This was due to the fact that ozone is quite unstable and quickly breaks back down into oxygen. This meant that effluents could be treated in the same way as urban wastewater; Achievement of better environmental results than current CIP practice while maintaining, at least, the same level of efficiency in terms of cleanliness and disinfection; Reduced energy costs, and; Reduced use of disinfectants, in particular chlorine, one of the most commonly used disinfectants for water.The results achieved at the end of the project should make it possible to consider the Ozone CIP technology as a BAT/BATNEC (Best Available Technology Not Entailing Excessive Cost) in the next version of the BREF for the sectors studied by the project. Further information on the project can be found in the project's layman report (see "Read more" section).