The invention relates to the use of a sterilization agent comprising H2O2 (hydrogen peroxide) or a derivative thereof. 
Sterilization in the context of the present invention means any process that eliminates or kills all forms of life, including transmissible agents, such as fungi, bacteria, viruses, spore forms, etc.  present on a surface, contained in a fluid, in medication or in a compound such as biological culture media.  Sterilization methods include applying the proper combinations of heat, chemical agents, irradiation (gamma rays, e-beam, etc.),  high pressure and/or filtration. 
Sterilization of objects, in particular object used in medicine, such as objects that have contact with blood during use is known since long.  Commonly used sterilization procedures use ETO or other chemicals such as ozone or hydrogen peroxide, gamma radiation, steam, or combinations thereof.  In this regard, reference is made to EP 1 175 230 and EP 1 455 843 and the prior art cited therein. 
In many medicinal operations, e.g. surgeries and extracorporeal blood circulation applications, such as in hemodialysis, wherein wastes and water are removed by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane, the sterility of the objects in contact with blood is extremely important. 
This is because patients who have to undergo a treatment including extracorporeal blood circulation, especially hemodialysis patients with nearly daily treatment, suffer a strong risk of inflammation which can in the worst case end in a sepsis. 
In extracorporeal blood circulation applications, it is furthermore important that the blood does not coagulate or the quality of the blood is deteriorated while the blood is outside of the body.  Due to this, it would be advantageous to dispose over a sterilizer which eases the transport and the storage of blood in extracorporeal blood circulation applications. 
Any of the above mentioned sterilization methods has an impact on the surface properties of the sterilized object.  In the case of chemical agents, these can as well penetrate into the surface of the object and remain there, if the same has a porous structure. 
Some of the sterilization methods have a reduced compatibility with certain materials.  For example, gamma radiation has a degrading effect on the surface of polypropylene objects.  Yet, for other materials, a certain sterilization method may have a positive or negative effect on the surface in view of certain applications. 
Therefore, it is an object of the present invention to provide a sterilization agent, in particular for extracorporeal blood circulation applications that assures a safe and reliable sterilization and influences the surface of objects in a positive manner for the contact with blood while being easily and economically to implement in a sterilization process.