I want to preface by saying I rarely write reviews, but after using this Zojirushi water boiler/warmer for 2 years straight, I need to write this review and warn other potential buyers about the serious health hazards that come from using this product. I wish I had heed the warnings/input from the 1-star reviews, but with so many positive 4/5 stars reviews from a brand that is known for quality, you tend to overlook the blemishes. Like many others, when this water boiler/warmer first arrived, it was a modern marvel of convenience to have hot water readily available at a moment's notice. Everything worked flawlessly as intended, so I can definitely understand the high marks that it receives. However, over time(after the 1 year mark), the water boiler started emitting a slight plastic smell whenever the lid is open for refill. The water also started having a hint of plastic taste to it. I overlooked this as something normal since the hot water sits overnight in a vacuum, so some slight smell is probably expected. I usually drink my hot water with tea/other mixes, so the plastic taste is masked. Over time, the plastic smell eventually became too strong to ignore; it was this vapory plastic smell whenever the lid was opened. What was most perplexing was figuring out where the smell was coming from. I checked the canister and there was no issue with it besides some slight discoloration. There was no rust or mineral build-up(non hard water). I had read reviews about the lid melting or the gasket needing replaced, but everything looked fine on the surface. It wasn't until I saw some white flakes(by chance) fall into the water that I started really inspecting the lid. The underside of the lid is covered by a metal plate with two holes for the steam to escape and is held by three screws. I decided to unscrew the three screws so that I can remove the metal plate. What I saw inside the lid alarmed and frightened me. Much of the plastic structure around the vent holes had melt away and dissolved to fine powder upon touch. I finally understood what others said about the lid plastic melting. Just by looking at the lid, you can't really tell; you have to unscrew/remove the metal plate to see the plastic and conditions of the lid. This whole time, with the vapory plastic smell and taste, I had been consuming plastic bit by bit with each cup of hot water. And to think about and literally see the amount of plastic I had already consumed, along with others in my family, is very unnerving. It is unfathomable that such a high-end, top of the line water boiler/warmer has such a serious flaw in the lid. For the price, one would expect the product to be long lasting, providing continuous use, and not have to worry about replacing the lid every 1-2 years. There is no reason why the internals of the lid can't be made of stainless steel as well, and this is actually an easy fix. Zojirushi knows about this problem; their only suggestion is to replace the lid, which will set you back another $30+. It is one thing to milk the product by selling lids, but when people are ingesting plastic, especially parents with newborns who depend on this for the baby formula, this becomes a serious health hazard. We are all familiar and concerned with the exposure to plastic(bpa) in our food. I consider myself attentive and savvy, but there are others who may not know how to inspect the lid or even aware that plastic on the inside is melting, since it's not apparent on the surface.I implore everyone who owns this water boiler(or similar models) to check their lids for melting plastics. To do so, first remove lid from boiler, then unscrew the three screws(phillips screwdriver) holding the metal plate. Underneath it, you will see the current condition of the your lid/plastic. If your lid has not shown sign of heat damage, please be mindful to check it periodically and especially when you first smell/taste plastic because this will happen over time due to the repeated exposure to extreme heat/steam.TLDR: HEALTH HAZARD due to the design flaw of the lid, whereby plastic internals are exposed to the extreme heat/steam through vent holes after each boil. It is not a matter of if but when the plastic will start melting/disintegrating and leaking into the water.