Since Tupperware, the iconic kitchen brand that’s been a household name for decades, signaled recently that it might be going out of business, you might be wondering how long your stash of its food storage containers is safe to use — especially if it’s vintage. Figuring out the answer to that question for any type of reusable plastic food storage products — not just Tupperware — often comes down to understanding what they’re made of. Bisphenol A, more commonly known as BPA, is a chemical that, according to the United States Institute of Environmental Health Sciences, has been used for years in the production of certain plastics to make them more durable and shatter-resistant. Unfortunately, it can also make them potential health hazards. ....