 Canada's definition for a Microbead is any artificial bead made out of synthetic polymer particles that is greater than 0.1 micrometer and less than or equal to 5 millimeters in size.America's definition for a microbead is slightly different, and is defined by congress as any solid plastic particle that is less than 5 millimeters in size that was created with the intention of being used to exfoliate or cleanse the human body.In this case, America's definition lacks a lower size limit for a microbead while Canada's definition has both a lower limit and higher limit.