If you rarely think about your toilet seat, you’re not alone. Most of us assume that as long as it doesn’t look gross, it doesn’t need to be replaced. But that’s not necessarily true. “Toilet seats are one of the most used but most overlooked items in the bathroom when it comes to routine replacement,” says cleaning expert Stephanie Leichtweis. “But even small cracks or surface wear can make the seat harder to fully clean over time.” That’s because those cracks encourage bacterial and mold growth, creating unsanitary conditions. Here’s how to know when it’s time to change your toilet seat , pick a replacement and install it. How Long Do Toilet Seats Last? How long a toilet seat lasts depends on the material it’s made from and how often it’s used. The most common plastic-type seats — those made from polypropylene or thermoplastic — generally last five to seven years before the surface starts to look worn, and micro-cracks become a breeding ground for bacteria.…