If you notice any rust-like corrosion on your Stanley product, it could be caused by free-iron particles, dirt, or residue that have contaminated the surface. To remove these contaminants, we recommend using a standard, non-abrasive household cleaner with a bristle brush, sponge, or clean cloth. A stainless-steel cleaner or polish can also be effective in removing rust. Additionally, soaking the product in a mixture of warm water and baking soda, white vinegar, or lemon juice may help remove stubborn rust stains. After cleaning, be sure to wash your bottle thoroughly as recommended in our care and use instructions. With proper care, Stanley products made of high-grade stainless steel can last a lifetime.