Why is plastic 7 bad?

Why Plastic 7 Can Be Problematic

If a bottle is marked with the number 7 and features the letters "PC," it likely contains BPA. While all polycarbonate bottles are classified as number 7, some manufacturers may choose not to include the "PC" designation. It’s important to note that not every plastic with a number 7 label has BPA; however, if the bottle is clear and rigid while bearing this number, it may potentially contain BPA.