used in the alternative lug plate 102 may simply be made integral with cover plate 104 with no splash protection although adapting lug plate 102 to a splash prevention tube is preferred for the present invention syringe 704 in fig8 is shown disengaged from the central hub 701 and pressing the disengaged needle downward in direction 706 at needle engagement tip 705 it will be appreciated that needle engagement tip 706 can be substantially different in configuration than that shown in fig8 such as for luer u00ae lock or vacuum tube adapters i e tubular needle supports and still accomplish the objects of the present invention one of the most important of the advances made by the present invention is the elimination of side to side motion necessary for locking engagement of prior art needle unlockers such side to side motion with surfaces made slippery by water or body fluids increases the risk of slipping and injuring personnel during the needle unlocking and disposal operation a needle hub engaged to a vacuum tube adapter or syringe will be referred to herein as a device attached needle hub being construed to mean needle hubs with a cross sectional profile exhibiting lateral extensions from the hub or other such means to effect unlocking by twisting motion as with square cross section needle hubs or the like and engaged to relatively rigid devices for injection or withdrawal of fluids it will be understood from the above disclosure.