The ISO 18184 test standard has been devised to test the capability of textiles and other related materials to destroy virus. Standard virus exposure times vary from 2 hours to less than 24 hours. Different viruses may possess intrinsic sensitivity to the underlying material, so a control material is also incorporated to determine the antiviral effects of the treated textile over any intrinsic antiviral performance of the test substance.
Many virus varieties can be examined; familiar instances include influenza and corona virus strains. The authentic performance of the treated textile is determined by viral titer measurements using a plaque assay or TCID50 method (Median Tissue Culture Infectious Dose) comparable to a most feasible number serial dilution measurement.
The ISO 18184
Common Antimicrobial Additives
Standard mechanisms for antiviral activity need additives that can chemically or dynamically alter some aspects of the virus. Drug strategies depend on distinctly 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 obstructing its motive movement.
For treated products, a more traditional approach is to chemically attack a more common feature of the virus. For coronavirus, which has a fatty (lipid) cover, antiviral products will stick to the membrane and interrupt it by making it lose its typical structure and, therefore, its ability to infect. Basic classes of antimicrobials for that activity used in textiles are quaternary ammonium combination , essential oils, and quaternary-silane molecules (quat-silane), which are comparable to surfactants or detergents but are coupled with added chemical functions to allow for their sustainable use.
Another way of antiviral activity uses a contrasting chemical approach that oxidizes the material on exposed facets of the virus; once oxidized, these viral elements can no longer function biologically and are inactive. Typical classes of antiviral and antimicrobial combinations that use this strategy are chemicals like hypochlorite or bleach. These tend to be of less use due to a absence of sustainability , but are still used as an productive cleaning mechanism.
Many buyers will request durability testing as an element of the ISO 18184 method to determine a product’s antimicrobial performance against viruses when disclosed to environmental conditions. Utilizing both Durability and Antimicrobial testing through Situ Biosciences’ product test laboratory can assist product development and performance testing while minimizing the time and costs associated with developing and distributing standard products. One circumspection is that durability assessments need to be well managed for the effects of residual cleaning products and, therefore, must be well designed for the aimed purpose of the treated product.
