padimate a padimate a padimate a is an organic compound that is an ingredient in some sunscreens. it is an ester derivative of paba. this aromatic chemical absorbs ultraviolet rays thereby preventing sunburn. however, its chemical structure and behaviour is similar to an industrial free radical generator. in europe this chemical was withdrawn in 1989 for unstated reasons. in the us it was never approved for use in sunscreens. padimate a names preferred iupac name 3-methylbutyl 4-(dimethylamino)benzoate other names isoamyl dimethyl pabaescalol 506, 4-dimethylaminobenzoic acid isopentyl ester identifiers cas number 21245-01-2 y 3d model (jsmol) interactive image chemspider 80159 n echa infocard 100.040.247 pubchem cid 88836 unii 956679a27p y comptox dashboard (epa) dtxsid3046580 inchi inchi=1s/c14h21no2/c1-11(2)9-10-17-14(16)12-5-7-13(8-6-12)15(3)4/h5-8,11h,9-10h2,1-4h3 nkey: ofsauhschwrzkm-uhfffaoysa-n ninchi=1/c14h21no2/c1-11(2)9-10-17-14(16)12-5-7-13(8-6-12)15(3)4/h5-8,11h,9-10h2,1-4h3key: ofsauhschwrzkm-uhfffaoyam smiles cc(c)ccoc(=o)c1ccc(cc1)n(c)c properties chemical formula c14h21no2 molar mass 235.322 melting point <25 °c except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references photobiology the photobiological properties of padimate o and padimate a resemble that of michler's ketone. these compounds have been shown to increase the lethal effects of uv-radiation on cells. this photochemistry is relevant to the sunscreen controversy.