Ampac's 400 Series SealPAK is a 2ply laminated structure consisting of polyester and polyethylene (PET/PE). These boilable and freezable pouches can sustain temperatures from -56 to 115°C (-70 to 240°F). 400 Series SealPAKs are 2.5 mils thick, and are best used for light use and moderate protection. These transparent, airtight, and leak-proof pouches can be sterilized with gamma, infrared, and e-beam. Once sealed, these pouches can also be surface sterilized using VHP.