Flip top cap

A lid mounted in proximity to an open top of a laboratory vessel by a hinge, the lid having a top wall configured for closing the open top in the vessel, an outer wall for telescoped engagement over said open top of said vessel, said outer wall defining a shield projecting from the top wall and configured for at least partly surrounding said open top of said vessel, portions of said outer wall spaced from said shield projecting a shorter distance from said top wall than portions of said outer wall that define said shield, at least one projection facing outwardly on said shield at a location spaced from said hinge, said projection and said shield being dimensioned and configured for preventing digital contact with portions of the vessel adjacent the open top during hinged rotation of said lid relative to the vessel, and an inner wall dimensioned for telescoping into said vessel for sealing said vessel, said shield being between said projection and said inner wall of said lid, wherein outer surface regions of said inner wall are formed with notches for equalizing pressure during an early stage of opening said lid to avoid generating splashes during opening of said lid.