Ozone has garnered public attention for its potential to eliminate viruses, particularly in the context of disinfection. This article explores how ozone interacts with viruses, where it is applied for disinfection, and the important safety considerations associated with its use.
Understanding Ozone and Viruses
Ozone (O₃) is a molecule composed of three oxygen atoms, forming a pale blue gas with a distinct pungent odor. It is a highly reactive, powerful oxidizing agent that readily reacts with other molecules by taking their electrons. Ozone is unstable, quickly breaking down into a more common and stable form of oxygen.
Viruses are microscopic, non-living infectious particles that cannot replicate on their own. They consist of genetic material, either DNA or RNA, encased within a protective protein shell called a capsid. Some viruses also possess an outer lipid envelope, derived from the host cell membrane. Viruses reproduce by invading living host cells and commandeering their cellular machinery to create more viral particles.
How Ozone Inactivates Viruses
Ozone inactivates viruses through its strong oxidizing properties, directly damaging their structural components. For enveloped viruses, including SARS-CoV-2, HIV, and influenza H1N1, ozone primarily attacks the outer lipid envelope. This envelope is crucial for the virus to attach to and enter host cells, and its destruction by ozone renders the virus non-infectious.
Ozone’s oxidative action extends to other viral structures. It can damage the proteins that make up the viral capsid and directly destroy the genetic material (DNA or RNA) within the virus. This chemical reaction leads to a breakdown of the virus’s integrity and its ability to replicate or infect host cells. Ozone can also disrupt the virus’s capacity to bind to target cell receptors, preventing infection.
Where Ozone is Used for Disinfection
Ozone’s virucidal properties are harnessed in controlled environments where its concentration can be carefully managed. A widespread application is in water treatment, including municipal drinking water facilities, wastewater treatment plants, and swimming pools. In these settings, ozone improves water quality by removing undesirable tastes, odors, and colors.
Ozone is also employed for air purification and surface disinfection in industrial and medical settings, such as hospitals. It sterilizes rooms, equipment, and tools. Pharmaceutical industries utilize ozone to ensure the purity of water used in their processes and for treating wastewater, benefiting from its ability to be generated on-site and decompose without leaving harmful residues.
Important Safety Considerations
While ozone eliminates viruses, it is also a toxic gas that poses significant health risks to humans and animals at concentrations required for effective disinfection. Inhaling ozone, even at low levels, can irritate the respiratory tract, leading to symptoms such as coughing, chest pain, shortness of breath, and a sore throat. It can also aggravate pre-existing respiratory conditions like asthma and compromise the body’s ability to fight respiratory infections.
Individuals, including children, older adults, and those with asthma or other respiratory diseases, are particularly susceptible to ozone exposure. Ozone generators should never be operated in spaces occupied by people or pets. After ozone treatment, the area must be thoroughly ventilated, and sufficient time allowed for the ozone to dissipate before re-entry. Consumer-grade ozone generators marketed for household air purification are generally not safe or effective, as the concentrations needed to kill viruses are unsafe to breathe. Ozone can also react with other chemicals found indoors, potentially forming new and harmful byproducts.