Viruses are microscopic entities that can cause a variety of infectious diseases, from the common cold to more severe illnesses like COVID-19. In the fight against viral infections, disinfectants play a crucial role by inactivating viruses on surfaces and in environments where transmission could occur. The European Standard, EN 14476, provides a rigorous framework for testing the virucidal activity of chemical disinfectants to ensure that they are effective against the viruses which they claim to target. This article explores the importance of EN14476 for virucidal disinfectants, explaining the significance, process, and implications of these standards.
Understanding EN 14476 for virucidal disinfectants
Scope and Significance
EN 14476 provides a test method to certify the effectiveness of disinfectants that claim virucidal activity. This standard is applicable to products which are used in various settings including healthcare, domestic, and industrial environments. This standard is important as it plays a vital role in validating claims made by the manufacturers of disinfectant products, thus ensuring public health safety and preventing the spread of viral infections.
Testing criteria
The virus is exposed to the disinfectants in the presence of organic matter for specific contact time as recommended by the manufacturer. After the contact time is over, the disinfectant is neutralized and its antiviral efficacy is determined by titrating the residual live virus. The test also includes the determination of cytotoxicity of the disinfectant.
Test Methods in EN 14476
Virus selection
Both enveloped and non-enveloped viruses are tested to assess the virucidal efficacy of disinfectant products.
- Enveloped viruses include viruses like influenza virus, vaccinia virus and coronavirus. These viruses are usually more susceptible to disinfectants.
- Non-enveloped viruses such as Adenovirus, Norovirus, and Poliovirus are more resistant to disinfection.
The virus strain selection for testing virucidal disinfectants depends on the product’s field of application and the claims made by the manufacturer.
Test virus preparation
The viruses used in testing are prepared using a suitable cell line that allows for the optimal replication of the virus. This preparation involves:
- Infecting a compatible cell line with the virus.
- Harvesting the virus at a specific time post-infection.
- Determination of viral titer by TCID50 method or by plaque assay.
Test Conditions
The test conditions should closely simulate real-world conditions where the disinfectant will be used.
- Temperature and Humidity: These conditions are adjusted based on typical environmental conditions expected in the application areas (e.g., medical facilities, and laboratories).
- Interfering substances: Tests are performed in the presence of an organic load such as blood or saliva or other organic matter to simulate practical conditions.
Applying the disinfectant
The disinfectant is applied to the virus in a controlled manner:
- Concentration of disinfectant: The exact concentration of the disinfectant as recommended by the manufacturer or a standard concentration if evaluating the basic virucidal activity.
- Contact time: The contact time (duration for which the virus stays in contact with the disinfectant) varies depending on the instructions provided by the manufacturers.
- Volume and ratio: Sufficient volumes of disinfectant solution must be taken so that the virus can be uniformly exposed to the disinfectant while maintaining the concentration of disinfectant.
Virucidal activity evaluation
The reduction in viral infectivity is assessed by
- Post-exposure processing: An aliquot of the test mixture is added to the neutralizing solution after the contact time to stop the action of disinfectant.
- Infectivity assay: The treated virus is then inoculated onto a susceptible cell line to determine the viral titer. The extent of viral infection is monitored by observing cytopathic effects or using other quantifiable means like plaque assays or TCID50 determination
Interpretation of Results
The reduction in viral activity is quantified in terms of log reduction. A disinfectant is considered effective if it achieves a log reduction in virus concentration by a factor specified in the standard (usually at least a 4-log reduction for viruses).
Reporting
All the test results must be documented thoroughly including information on the type of virus tested, conditions used, and the results obtained. This documentation is important for regulatory compliance and for manufacturers to support their virucidal claims and receive product approval.
EN 14476 compliance and its impacts
Regulatory compliance
Manufacturers must ensure that their products meet the standards set by EN 14476 to be labeled and marketed as virucidal.
Effects on Public Health
EN 14476 compliant products used in various environments like hospitals, schools, and public transport systems, provide efficient protection against viruses thus reducing the risk of infection and contributing to public health safety.
The benefits of understanding the EN 14476 guidelines
- Manufacturers can design and test their antiviral products to meet efficacy criteria stipulated as per EN 14476 standard.
- EN 14476 standard helps ensure that the disinfectant products meet the required efficacy standards, hence supporting consumer safety.
- EN 14476 certification can help consumers and professionals make the right decisions about the disinfectants that they use on the basis of proven effectiveness against viruses.
Role of MIS
At Microbe Investigations Switzerland, we specialize in EN 14476 testing which is crucial for validating the virucidal activity of disinfectants. Our experienced team of virologists employs rigorous protocols to ensure your products meet the highest standards for effectiveness against viruses. Partner with MIS to guarantee the reliability and safety of your disinfectants, enhancing consumer confidence and compliance with industry regulations.
For more information on our EN 14476 testing services or to consult with our experts on how to validate the virucidal efficacy of your products, please contact us today.
