Virucidal

Virucidal refers to the property of a substance or process that inactivates or destroys viruses. A virucidal agent reduces or eliminates the ability of a virus to infect a host cell. Virucidal activity is typically demonstrated in laboratory tests and is distinct from antiviral drugs, which act inside living organisms to inhibit viral replication, and from general antiseptics or disinfectants that may target bacteria or fungi as well as viruses.

Virucidal action can be achieved by chemical disinfectants or physical methods. Chemical virucides include oxidizing agents such as hydrogen peroxide and peracetic acid, chlorine-based compounds, alcohols (ethanol and isopropanol), and certain aldehydes or quaternary ammonium compounds. Physical methods include ultraviolet light (UV-C) and heat, which can denature viral proteins or damage nucleic acids.

Effectiveness depends on virus type and environmental conditions. Enveloped viruses are generally more susceptible to many virucidal agents than non-enveloped viruses such as norovirus or adenovirus, which tend to be more resistant. Efficacy depends on concentration, contact time, temperature, and the presence of organic material or surface irregularities. Some agents may inactivate a broad range of viruses, while others have narrower spectra.

Regulatory labeling and testing vary by jurisdiction. Products marketed as virucidal are typically tested under standardized conditions and may bear claims based on regulatory approvals. In the United States, EPA regulatory listings include disinfectants with virucidal claims; in Europe, standards such as EN 14476 are used to substantiate virucidal activity. The term is often contrasted with virustatic or antiviral actions, which pertain to inhibition of viral replication within a host.