These 4 Mil pouches are just a little thicker than our regular 3 mil pouches. They will give you a little more protection from leakers especially if your product is subject to rough handling or very long truck rides! The 4 mil nylon/polyethylene vacuum pouches on this page are acceptable for use up to and including 149_F as packaging material in direct contact with food product. The U.S. Department of Agriculture requires meat, poultry and dairy plants to secure and keep on file guarantees from packaging suppliers stating that their packaging materials comply with the Federal Food, Drug and Cosmetic Act. We would be happy to provide you with that letter of guarantee. These pouches are available in 16 sizes as a 3 side seal pouch.