Abstract: Disclosed herein are methods and devices for the inactivation of pathogens (e.g., bacteria, viruses, etc.) in ex vivo stored blood products, such as plasma and/or platelets, by means of directing visible light radiation from an illuminating device into blood product storage containers in order to achieve effective pathogen inactivation without the presence of an added photosensitising agent in the blood product. An exemplary apparatus includes a control unit that operates a light source that emits light in the wavelength region of about 380-500 nm which is directed onto blood product storage bags at sufficient intensity to penetrate the bag material and the opaque blood product therein in order to inactivate pathogens in the blood product but at dose levels that cause no significant detrimental effects on the blood product.