Safety tap for containers for liquids which are sensitive to certain gases and environments, comprising a plastic bag to hold the liquid, and a stabilizing box of cardboard or similar, to house the bag, where the safety tap comprises: - a hollow base body, equipped with a first end, for being coupled to the bag, and a second end; - a sealing seat, incorporated in the base body, in the proximity of the first end of the base body; - an access orifice located in the sealing seat to allow the liquid to access from the bag to the tap; - a pouring spout to allow the liquid which has accessed the tap through the access orifice to exit the tap; - windows made in the base body; - a bushing displaceable through the interior of the base body; - ribs, located at a first end of the bushing and protruding from the base body through the windows, and which can be actuated, to allow a user to displace the bushing, distancing the bushing from the sealing seat, from a safety lock position, wherein the liquid does not have access to the pouring spout, until an open position wherein the liquid has access to the pouring spout; - a deformable elastic element linked to the base body; and - a plug located at a second end of the bushing, opposite the first end, and linked to the elastic element; where, in the closed position, the elastic element is pressed by the effect of the plug against the sealing seat to close the pouring spout, and in the closed position, the elastic element is configured to exert a recovering force on the bushing; characterized in that it further comprises grooves in the base body, in extension of the windows, to house the ribs in the closed position by axial rotation of the ribs and to block the axial displacement of the bushing, maintaining the closed safety position. - a hollow base body, equipped with a first end, for being coupled to the bag, and a second end; - a sealing seat, incorporated in the base body, in the proximity of the first end of the base body; - an access orifice located in the sealing seat to allow the liquid to access from the bag to the tap; - a pouring spout to allow the liquid which has accessed the tap through the access orifice to exit the tap; - windows made in the base body; - a bushing displaceable through the interior of the base body; - ribs, located at a first end of the bushing and protruding from the base body through the windows, and which can be actuated, to allow a user to displace the bushing, distancing the bushing from the sealing seat, from a safety lock position, wherein the liquid does not have access to the pouring spout, until an open position wherein the liquid has access to the pouring spout; - a deformable elastic element linked to the base body; and - a plug located at a second end of the bushing, opposite the first end, and linked to the elastic element; where, in the closed position, the elastic element is pressed by the effect of the plug against the sealing seat to close the pouring spout, and in the closed position, the elastic element is configured to exert a recovering force on the bushing; characterized in that it further comprises grooves in the base body, in extension of the windows, to house the ribs in the closed position by axial rotation of the ribs and to block the axial displacement of the bushing, maintaining the closed safety position.