EN 14476 – Quantitative suspension test for evaluation of virucidal activity in the medical area

En 14476 is an antiviral textile test that performs the measurement of viral antimicrobial activity for sanitizers and disinfectants.

The EN 14476 test method provides a test method for the quantitative evaluation of the virucidal activity.  Products intended for assessment by the test method are considered to be disinfectant and antiseptic products that are homogenous and stable, and may or may not be diluted before use (known as ready to use RTU, or as concentrates).   
As part of determining the appropriate scope for antiviral testing of a product, the intended category for the product application is used to define the exposure time and test conditions for determining the antiviral performance of the product.  The four product application categories are; Hygienic Hand Cleaners; Instrument Disinfection, Surface Disinfection, and Textile Disinfection.  For the different product categories, the exposure times range from 30 seconds to 60 minutes.   In addition to the exposure time, testing can incorporate hard water dilutions, soiling, and a range to different virus types.   

Many virus types can be tested, common types include influenza and coronavirus strains.  The actual performance of the treated textile is determined by viral titer measurements using a plaque assay or TCID50 method (Median Tissue Culture Infectious Dose) similar to a most probable number serial dilution measurement.

The EN 14476

Common Antimicrobial Additives

Standard mechanisms for antiviral solution testing require additives that can chemically or dynamically modify some aspects of the virus.  Drug strategies rely on highly specific binding to the virus (known as receptor-ligand binding) where the receptor is on the virus and the ligand is the drug used to bind to the receptor blocking its mode of action.

For treated products, a more common approach is to chemically attack a more general aspect of the virus.  For coronavirus, which has a fatty (lipid) envelope, antiviral products will adhere to the membrane and disrupt it by causing it to lose its characteristic shape and therefore its ability to infect.  Common classes of antimicrobials for that activity used are reactive aldehydes, oxides (hydrogen peroxide or peroxyacetic acid),  quaternary ammonium compounds, essential oils, and quaternary-silane molecules (quat-silane).

For liquid disinfectant applications, the priority tends for a fast rate of action, so the favored compounds commonly use are aldehyde chemistries (formaldehyde, and glutaraldehyde), hypochlorite, peroxides and to some degree quaternary ammonium compounds.   More commonly are combinations of compounds such as peroxides and quaternary ammonium compounds that can perform antiviral actions in a so-called ‘synergistic’ way, provide very fast action with a high-level of antiviral efficacy, at lower antimicrobial additive concentrations.

Many customers will request durability testing in companion with EN 14476 testing to determine the antimicrobial performance against viruses when exposed to environmental conditions.    The most commonly used forms for durability include soiling (or dirty) conditions, known as interfering substance.  Commonly serum, blood, or hard water are used.

Utilizing both Durability and Antimicrobial testing through Situ Biosciences’ product test laboratory can support product development and performance testing while reducing the time and costs associated with developing and distributing quality products on the market.  One caution is that durability assessments need to be well controlled for the effects of residual cleaning products and therefore must be well designed for the intended purpose of the treated product.


For more information about EN 14476 and antiviral treated products contact the lab at 847-483-9950 or info@situtest.com.