I had never heard this claim before, so I was initially skeptical, but after conducting some of my own research, I realized that this claim is, in fact, true. One of the most beloved water bottles, owned by so many, does in fact contain a lead pallet to seal the vacuum insulation on the base of the bottles. While there is plenty of false news on sites like TikTok about this topic, there are also valid articles out there from companies such as BBC and the Bouve College of Health Sciences that do verify these claims. The BBC article discusses the exact instance you are speaking about, how someone did a lead test at home and posted the results. What these articles discuss is that while these water bottles do contain some amounts of lead, the amount they carry fits all US regulatory requirements. The same article also points out how the type of lead testing kit the woman on TikTok used is not the most reliable for testing water bottles, and is more intended for testing water itself. So in conclusion, yes, these beloved water bottles might contain some levels of lead, but if you are comfortable risking it, it is a relatively safe level of lead that should not cause you any harm.