Retractable spout closure system with flame mitigation

A system for mitigating propagation of flames through an extendible/retractable dispensing closure configured to attach to a container neck, the system comprising:

• a fitment, partially defining an upper portion of a lumen that terminates in an outlet positioned at a top edge of the fitment, having:
• i) a flexible section interposed between a rigid spout section and a peripheral coupling edge and wherein the rigid spout section includes the upper portion of the lumen and the outlet, ii) a circumferential ledge in an inner surface of the lumen where the flexible section joins the rigid spout, iv) a removable, tamper evident panel sealing the lumen above the horizontal ledge, and v) a plurality of retention flanges protruding radially inward from an inner facing of the flexible section within a common spatial plane oriented parallel to and below the horizontal ledge;
• a removable cap detachably affixed to the rigid spout so as to conceal the tamper evident panel;
• a coupling ring secured to the coupling edge;
• a flame mitigating mesh element spanning the lumen and spaced apart from the top edge at an mesh axial distance;
• a cylindrical guard, snap-fitted to the fitment so as to capture the mesh element against the circumferential ledge, having:
• i) a hollow tubular main body with an guard inner diameter, ii) a capturing flange protruding radially outward from a top end of the main body, and iii) a guard axial distance defining a lower portion of the lumen and extending from the top end of the main body to an opening at a bottom end of the main body, and wherein the capturing flange is configured to cooperate with the retention flanges;
• wherein, when the tamper evident panel is removed so that fluid may be dispensed through the lumen, a ring section protrudes radially inward so that the ring section is spaced apart from the top edge at a ring axial distance and possesses a ring inner diameter;
• and
• wherein at least one of the following dimensional ratios applies:
• i) the ring inner diameter to guard inner diameter is between 1.001 and 1.050, ii) the guard inner diameter to guard axial height is between 0.731 and 0.893, and iii) the mesh axial distance to the guard axial distance is between 0.376 and 0.460.