Abstract: A container for photochemical materials has a frangible closure. The frangible closure has a central weakness and a central portion having a thickness and a central portion of greater thickness than the thickness of the central weakness. A radial weakness connects with the central weakness enabling the central weakness to collapse in response to an applied predetermined force.

Abstract: A frangible closure has a closure sheet having a central weakness formed substantially though a medial portion. The central weakness has a thickness and a central portion of greater thickness than the thickness of the central weakness so as to resist shearing of the central weakness. A lateral skirt surrounding the closure has at least a partial radial weakness therebetween for cooperating with the central weakness and enabling the central weakness to fracture.

Abstract: A fluid transfer system suitable for emptying a container or flask closed by a liquid-tight removable frangible closure obtained from a material that can be recycled. Photoprocessing materials are transferred from a first container having the frangible container into an adjoining second container. The frangible closure has a single closure sheet fixed to a lateral skirt for mounting the frangible closure on the spout of the flask, for example with a screw. The flask is emptied by tipping the flask onto a perforation device that perforates a central weakness in the closure sheet which connects with a radial weakness at the seam of the closure sheet and lateral skirt, allowing for lower puncture forces.