ISO 21702 is used to determine the antiviral activity of treated non-porous surfaces such as plastics. A 5 x 5 cm section of product is inoculated with the relevant virus, Influenza A and Feline calicivirus are referenced in the standard but the method can be adapted for other viruses. A 4 x 4 cm coverslip is placed on top to ensure contact with the active over the whole area. The sample and virus is then incubated at room temperature in a humidified chamber for 24 hours. The material and coverslip are then washed with a liquid neutraliser or similar to recover the remaining virus. The amount of virus surviving on the test article is quantified and the antiviral activity calculated.