Synonyms: 2-Imidazolin-1-yloxy,4,4,5,5-tetramethyl-2-phenyl-, 3-oxide (8CI); 2-Phenyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxy3-oxide; 2-Phenyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl3-N-oxide; 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide;4,5-Dihydro-4,4,5,5-tetramethyl-2-phenyl-1H-imidazol-1-oxy 3-oxide; PTIO; a-Phenyltetramethylnitronylnitroxide