The minimum headspace in food cans should be about 4 to 5 mm, depending on the height of the container, to prevent food residues in the seal area and to avoid deformation of the flanges. In addition, it is advisable to leave a headspace corresponding to at least 6% of the capacity (volume) of the container (never less than 5%) to allow the expansion of the contents during heat treatment and the correct formation of the desired vacuum.