Use of ozone in food industries for reducing the environmental impact of cleaning and disinfection activities

Background: cutting the environmental cost of cleaning in food factories

Cleaning and disinfection are unavoidable in food manufacturing, but they carry a heavy environmental cost. In some plants these operations account for roughly 60 to 80 per cent of total water use, and they generate large volumes of wastewater loaded with detergent and disinfectant residues. Conventional chlorine-based sanitisers can also leave undesirable by-products such as trihalomethanes. At the same time, European legislation like the IPPC Directive (96/61/EC) has pushed food processors to adopt cleaner, less wasteful methods. This review sets out to examine whether ozone can meet that need as a more sustainable alternative for cleaning and disinfection.

What this review covers

The paper is a narrative review that draws together published research and industrial case studies on the use of ozone, applied both as a gas and dissolved in water, for sanitation across the food and drink industries. It looks at how ozone works as an antimicrobial agent, the concentrations and contact times reported in the literature, its effects on water and wastewater, the materials that are and are not compatible with ozone, and the occupational safety considerations that come with its use. Examples are drawn from sectors including dairies, breweries and wineries, and the work is framed within the European OZONECIP project, which aimed to validate ozone cleaning across these industries.

Findings: broad-spectrum sanitising with less water and fewer chemicals

The review reports that ozone is a powerful, broad-spectrum antimicrobial that is active against bacteria, fungi, viruses, protozoa and spores, acting by breaking down cell walls rather than by a mechanism that encourages microbial resistance. Studies cited show useful microbial reductions at concentrations of roughly 0.5 to 3.5 ppm. Dissolved in water, ozone typically achieved its effect within about 1 to 10 minutes, whereas gaseous application required longer exposure of several hours.

Because ozone breaks down quickly back into oxygen, it leaves no persistent chemical residue, which the review links to cleaner wastewater with lower chemical load and reduced electrical conductivity, and to the possibility of reusing ozonated water between cleaning stages. One case study cited a fall in daily water consumption from 56.8 to 22.7 cubic metres. The review also notes practical industrial examples, such as replacing chlorine-based sanitisers and controlling spoilage organisms during barrel sanitation in wineries. Other reported advantages include faster action than some alternative disinfectants, low-temperature operation and the removal of the need to store hazardous chemicals on site.

What the authors concluded

The authors conclude that ozone represents a viable and environmentally favourable option for cleaning and disinfection in the food industry, with the potential to qualify as a Best Available Technique under European environmental directives. In their view, the reductions in water use, chemical consumption and wastewater load, together with the absence of persistent residues, can offset the higher initial investment over time. They point to the OZONECIP project as the vehicle for validating these benefits in real dairy, brewery and winery settings.

Limitations of this review

This is a review and technical overview rather than a single controlled experiment, so it synthesises evidence and case-study figures of varying design rather than testing ozone under one standardised protocol. The authors are candid about several practical constraints. Ozone systems carry a higher capital cost than chlorine-based ones, and each installation needs a tailored feasibility study rather than an off-the-shelf solution. Material compatibility must be checked in advance: ozone is compatible with materials such as PTFE, PVDF, PVC and 316L or 304L stainless steel, but degrades natural rubber and, over time, silicone. Ozone is also a respiratory hazard, so exposure must be controlled within occupational limits (commonly cited as around 0.1 ppm over an 8-hour shift, with a short-term ceiling near 0.3 ppm) using monitoring and off-gas destruction. The findings relate to industrial food-processing sanitation and should be read in that context.