Abstract: A protective device for use with a hypodermic syringe for preventing accidental needle sticks after fluid has been ejected from the syringe and rendering the syringe non-reuseable. The protective device comprises a hollow, cylindrical casing defining a forward end wall having an opening therein, a rearward open end and an angular gripping flange adjacent the rearward end. The casing is adapted to be disposed about the syringe such that the syringe is reciprocally translatable therein with the syringe needle projecting through the opening in the forward end wall of the casing and the angular gripping flange axially spaced from the syringe flange. A dual component foaming agent is disposed in the casing adjacent the forward end wall thereof which, when the components thereof are mixed together activate to form an expanding and hardening plastic foam.