Sebum oil is also naturally produced by the hair follicle of your body, including hundreds of thousands of them on your face. When your skin sheds dead skin cells, they can get into the follicle and get mixed with the oil. This can
form a plug that pushes to the surface and forms a bump. When the skin around the pump opens and air gets in, then this sebum oil will oxidize and turn black. Proper face cleansing therefore becomes very important.
How are blackheads formed?”