Catalyzes both the acetyl-CoA-dependent N-acetylation of aromatic amines and the O-acetylation of N-hydroxyarylamines. In vitro, catalyzes the O-acetylation of N-hydroxy-Glu-P-1, and the N-acetylation of isoniazid and 2-aminofluorene. acetyl-CoA + an arylamine = an N-acetylarylamine + CoA acetyl-CoA + an N-hydroxyarylamine = an N-acetoxyarylamine + CoA Inhibited by N-ethylmaleimide and iodoacetamide. Monomer and homodimer. Belongs to the arylamine N-acetyltransferase family.