PAH

PAH or Pah may refer to:

==Science and technology== === Chemistry === Polycyclic aromatic hydrocarbon, one of a class of chemical compounds, organic pollutants PAH world hypothesis, hypothesis that proposes that the use of polycyclic aromatic hydrocarbons was a means for the origin of life Polyallylamine hydrochloride, a polyelectrolyte used in polymer sheets Polyanhydrides, a class of biodegradable polymers Photoacid, where H indicates an H atom lost by an acid