Not all metal bottles are created equal when it comes to health and human safety. Ever since the very first Klean Kanteen was released in 2004, they have chosen to make their bottles from high quality, 18/8, food-grade stainless steel – a metal superior in both strength and safety that contains no harmful chemicals or toxins, including BPA. In fact, the National Toxicology Program recommends choosing glass, porcelain, or stainless steel containers to prevent exposure to BPA. And unlike aluminum bottles, there's no requirement for a liner in Klean Kanteens, since stainless steel is recognized around the globe as a safe, food-contact material. Sure it costs more to produce a stainless steel bottle compared to aluminum or plastic, but they've always thought you were worth it.