Polyethylene microbeads?
D000571:American Dental Association; D003257:Consumer Product Safety; D006801:Humans; D008863:Microspheres; D020959:Polyethylene / Q000737:chemistry*; D014100:Toothpastes / Q000737:chemistry*; D014481:United States
D014100:Toothpastes; D020959:Polyethylene