Abstract: A sanitary or safety guard for a medical device subject to contamination, the medical device having a recess in its external surface, the guard comprising:(a) an elongate, hollow guard body having an internal chamber, an internal surface, an external surface, a first opening, and a second opening, the first and second openings being located at opposite ends of the guard body, the first opening being sufficient to allow at least a portion of the medical device to enter into the internal chamber and the second opening being sufficient to allow a portion of the medical device to extend from the internal chamber through the second opening;(b) a passage extending through the guard body between the internal and external surfaces;(c) a biasing arm connected by hinging means to the guard body;(d) an intrusion tab secured to the biasing arm such that the biasing arm projects the intrusion tab through the passage into the internal chamber of the guard body;(e) locking means secured to the guard body such that the locki