The virucidal activity of ozone occurs rapidly following ozonation (28-30). As with many other products used in disinfection, there is no specific information on efficacy against SARS COV-2. On the other hand, several studies are available that support its virucidal efficacy (Norovirus) in healthcare and non-healthcare settings (29). Even at low concentrations, with high humidity, ozone has a high virucidal disinfectant action in the air (30)
The International Ozone Association ( www.ioa-pag.org ) confirms the effectiveness of ozone for the inactivation of many viruses even if it is not aware of specific research on SARS-CoV-2.
At the industrial level, ozone is generated in situ by ozonizers, which must be adapted from time to time in relation to the spaces (dimensions, materials involved) and the targets (11,19,20,21,22,23 , 24.25). Ozone generators must comply with the directives on low voltage (Directive 2014/35 / EC), electromagnetic compatibility (Directive 2014/30 / EC) and Directive 2011/65 / EC (RoHS) on the restriction of hazardous substances
Ozone is an unstable gas and spontaneously decays to oxygen (31,32,33). The time required for ozone decay, which depends on temperature, humidity and chemical and biological contamination, and is always a function of the concentrations of use.
In real conditions, the natural decay time required to make the premises accessible is at least 2 hours. If possible, it is preferable to carry out the treatments at night so that when work is resumed the quantity of ambient ozone is within the health safety limits.
Avoid eliminating residual ozone by resorting to forced ventilation to convey it to the external environment: Legislative Decree 155/2010 (67) sets limit values and quality objectives also for concentrations of ozone in the ambient air.
On the basis of the CLP and REACH regulations (34,35), registrants have classified, under self-classification, ozone as: substance that can cause or aggravate a fire; lethal if inhaled, causes severe skin burns and serious eye damage, causes damage to organs in the event of prolonged or repeated exposure by inhalation, very toxic to the aquatic environment with long-lasting effects. Some notifiers identify ozone as a suspected mutagen. The competent German authorities expressed their intention to ECHA in 2016 to propose a harmonized classification and labeling for ozone also as a category 2 mutagen and a category 21 carcinogen.
Source: www.iss.it
