A blood collection device comprises an open ended syringe like housing into which a vacutainer can be inserted. The front of the device contains a needle holder and a double ended needle. The needle holder is attached to the device in a special manner that enables the needle holder to be decoupled and retracted into the device but only after the vacutainer has been removed and a separate needle retraction device has been inserted into the open end of the housing and pushed against the inner end of the needle holder. The needle retraction device comprises a hollow body which is under vacuum and which has an open end closed by a piston. The piston is of a special design that functions to decouple the needle holder from the blood collection device and to lock to the needle holder and at the same time to be decoupled from the hollow body the result of which is that the piston containing the needle holder and the attached contaminated needle is sucked back into the hollow body to render the needle safe.
