"Polyquaternium" means a synthetic polymer, a complex quaternary ammonium compound in which, as in "quaternium compounds", all 4 hydrogen atoms of the ammonium ion are replaced by organic side chains. The different representatives of the polyquaternium group are distinguished by trailing digits depending on the degree of polymerization.
Polyquaternium-2 is a substance which is used in cosmetic formulations. The substance acts as an antistatic agent (reduces static charges by neutralizing the electrical charge on the surface, e.g. of hair), combability aid (reduces or prevents tangling of the hair due to changes or damage on the hair surface and thus improves combability), emollient (makes the skin smooth and supple) and film former (forms a film on skin, hair or nails when applied).