At the end of the 1990s many countries started implementing pathogen inactivation methods for blood components dedicated for clinical use into routine work of blood transfusion facilities. A chemical — solvent detergent — method was developed as well as methods based on photochemical and photodynamic reactions with methylene blue, amotosalene hydrochloride and riboflavin. Although removal processes are used blood components subjected to inactivation with the above methods still contain traces of chemical compounds (the exception here is the riboflavin method). Attempts were therefore made to develop an inactivation method with no chemicals, based only on appropriate wavelength illumination. Theraflex UV Platelets system is the example of such inactivation method for platelet concentrates (PCs) based on UVC, with no photosensitizing compound. Therflex UV system makes use of 254 nm wavelength radiation, which is not absorbed by proteins, so there is no need for conventional toxicity tests. The method is effective for clinically significant G (+) and G (–) bacteria as well as viruses and protozoa. Clinical trials demonstrated reduced recovery of platelets inactivated by UVC and reduced survival time in the recipient’s organism.