A container includes a lid adapted to seal with a base. The lid and base rims each have vertical segments that mate upon sealing the container. The mating segments form a vertical seal zone. The vertical seal zone has a width extending across the rim surfaces. One or more vent channels are disposed on either or both rims. Each vent channel extends partially into the vertical seal zone. When pressure inside the container reaches a critical level, the lid rises and reduces the width of the seal zone, creating a vent point. Pressurized vapors traveling through the vent channel overcome rim-engaging forces at the vent point and pass through the engaged rims. Once pressure is purged, the lid descends and resumes its sealed arrangement with the base. The rims may respectively include horizontally oriented segments that engage each other to from a horizontal seal zone.