Whether you’re hand washing, using a plastic washing machine, or our Lowtemp Osprey, it's crucial to avoid metal zippers on work bags. These carbon steel metal zippers often have a zinc coating that flakes off into your material, and they can also scratch your expensive stainless steel vessels (impregnating carbon steel into the scratch, which can even start to rust or oxidize your vessel wall). Our No Scratch work bags fixes this issue by only utilizing 100% food grade Nylon throughout the zipper material, zipper handle, and 220u filter. Safe to use with The Osprey, any stainless steel vessel or machine, plastic washing machine, and even a great solution for normal hand washers looking to avoid carbon steel in their wash.