A black lip from a pencil is generally not carcinogenic. Pencils are composed primarily of graphite, or carbon, and do not contain lead, which usually does not have significant health effects. Cancer lesions are caused by changes in the structure and heterogeneity of cells and are not related to pencils. However, it is important to note that pencils may contain bacteria, and localized infections may occur when they puncture the lips, so it is important to remove the pencil lead foreign body and take care to prevent infections from occurring. If the pencil core is broken in the lips and can not be removed, it can be removed surgically under local anesthesia, good hygienic care of the affected area, you can use iodine povidone to disinfect the local area, and if there is any pigmentation residue, it can be removed by laser.