with the distal end of collar 34 it is preferred that the center projection or pin 54 be recessed with respect to outer projection 56 to help prevent accidental contamination of the pin and therefore to help prevent contamination of passageway 26 as illustrated most clearly in fig1 and 4 cover 36 of the protective cap is provided with a pair of tabs 60 and 62 which project outwardly from the collar of cover 36 the tabs are dimensioned to facilitate contact with the thumb or forefinger of the health care employee working with hypodermic syringe 10 to facilitate one handed opening an alternate syringe is identified generally by the numeral 110 fig6 the syringe 110 includes a syringe barrel 112 similar to syringe barrel 12 described and illustrated above syringe barrel 112 is characterized by a distal end 116 having a tip 124 with a passageway 126 extending therethrough a cylindrical sleeve 128 surrounds tip 124 in concentric spaced relationship a protective cap identified generally by the numeral 132 is connected to sleeve 128 of syringe barrel 112 the protective cap includes a hinge 138 joined to sleeve 128 and a cover 136 joined to the hinge hinge 138 and.