A scalpel blade accessory and cartridge are provided wherein a tubular guard is slideable over the scalpel blade carrier between a retracted position in which the blade carrier is positioned to expose any scalpel blade associated with it for use and an extended position in which the guard covers the blade carrier and any blade thereon. The scalpel blade has a mounting slot for attachment to a lug on a standard scalpel handle for use. The blade carrier has a bridge spanning an alignment face so as to provide space for a scalpel blade between the alignment face and bridge. A blade catch cooperates with a rear end of the mounting slot to hold a relevant scalpel blade captive. The blade catch is disengagable by assembling it onto a standard handle, in use.
