is a method of virus removal where a virus is inactivated with solvents, detergents, a low pH or UVC radiation. A disadvantage of this method lies in the partly incomplete inactivation of small, non-enveloped viruses. In addition, the procedures are generally dependent on the time or the temperature. The UVC-inactivation works with radiation of a low dose of 254 nm, which penetrates the virus and in smaller viruses irreversibly damages DNA and RNA 76. Commercially available, single-use systems are based on the pH inactivation 78.