Passive safety shield system for injection devices

A passive shield system for a syringe including a body (22), shield (24), spring (28) and ring(26) which provide an interlock of the shield in the retracted position prior to receipt of the syringe for bulk transportation and processing and wherein the user selects the timing of the release of the shield to its extended position following injection, but which assures sheilding of the syringe needle following the release of the syringe plunger.