Activated charcoal or activated carbon is nontoxic in nature and is used as an adsorbent to remove broad spectrum of pollutants in air, water and soil. It does not lose potency when kept in container. It has no odour or taste. It can be prepared from any carboneous material using chemical or gas activation methods. Gas activation is preferred when the raw material has less than 25% moisture content.

It may be used for fiber coating multiwalled carbon nanotubes to compare its solid-phase microextraction efficiency in water and milk samples before GC-ECD analysis.