It is true that there is no
blood in sperm, and that the mode of transmission for hepatitis C is
blood to
blood contact. But transmission through sexual contact does occur sometimes, though it is very rare. Just like mother to child transmission-it is just about 5 % chance, but it does happen.
You need to inform the person who asked you to be a donor about your hepatitis C status. She has the right to know and to make a decision.