We hate to break it to you, but there's some pretty nasty stuff hiding in your paste. Some of these substances have even been banned in hand soap! We call these bad boys the Toxic Ten. Artificial colouring is one of them: used to make commercial toothpaste aesthetically pleasing, artificial dyes may contain up to 10% impurities. Some of these undesired ingredients could include lead, arsenic, mercury and carcinogens. Get that out your mouth!