Ozonated Water for Disinfecting Hospital Instruments

Background: keeping hospital surfaces free of microbial contamination

Surfaces in hospital surgical centres - particularly the stainless-steel tables that hold instruments - can carry microbial contamination that contributes to healthcare-associated infections. A 70% alcohol solution is a common disinfectant for these surfaces, but it evaporates quickly and its cleaning performance can vary. The researchers set out to test whether ozonated water, a solution of ozone gas dissolved in water, could disinfect a metal instrument table at least as well as the standard alcohol routine.

Study design: comparing ozonated water with 70% alcohol using ATP swabs

The team ran an experimental comparative study in the surgical centre of a Brazilian hospital. Cleanliness was measured with adenosine triphosphate (ATP) bioluminescence swabbing, a rapid hygiene-monitoring method that reports organic residue as relative light units (RLU); lower readings indicate a cleaner surface, with values below 100 RLU taken as the acceptable threshold. Stainless-steel instrument-table surfaces were swabbed after disinfection, comparing ozonated water against 70% alcohol across 20 trials for each agent.

Findings: ozonated water recorded lower residue readings than alcohol

Ozonated water produced a higher measured disinfection effectiveness than 70% alcohol - reported as 98.1% versus 86.5%. Every surface treated with ozonated water returned an RLU value below the 100 threshold, whereas four of the alcohol-treated surfaces exceeded it. On the ATP measure used here, the ozonated-water routine left less residual organic material on the metal surface than the alcohol routine.

What the authors concluded

The authors concluded that ozonated water was more effective than 70% alcohol as a disinfectant agent for a metal surface in the hospital environment. They positioned it as a promising, low-residue option for surface disinfection in surgical settings, noting that it is prepared from water and oxygen and leaves no chemical residue.

Limitations of this study

This was a small experimental study carried out on stainless-steel instrument-table surfaces in a single hospital, with 20 trials per agent. It assessed surface cleanliness through ATP bioluminescence (organic residue) rather than culturing specific pathogens, so it does not report reductions in named micro-organisms. The stability of ozonated water depends on its concentration and how soon it is used after preparation, which can affect real-world results. The findings apply to environmental surface disinfection and should not be read as evidence about ozone used as a medical treatment.