Acne is not caused by dirt. This misconception probably comes from the fact that blackheads look like dirt stuck in the openings of pores. The black color is not dirt but simply oxidized keratin. In fact, the blockages of keratin that cause acne occur deep within the narrow follicle channel, where it is impossible to wash them away. These plugs are formed by the failure of the cells lining the duct to separate and flow to the surface in the sebum created there by the body. Built-up oil of the skin can block the passages of these pores, so standard washing of the face could wash off old oil and help unblock the pores.