P2 rated respirators are available with carbon activated filters for protection against nuisance-level organic vapours. Activated carbon, also called activate charcoal, is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. Activated carbon can be coated to masks in order to improve the effectiveness in reducing the pollutants. The activated carbon layer in P2 Safety Masks absorbs offensive odours in applications involving thermally generated particles (particularly welding). It controls odours and fumes, but does not protect against gases or chemicals.