The photodissociation of pernitric acid (PNA) has been studied at 248 nm. The quantum yield for production of OH radicals is 34¿16%. The yield of OH from PNA was measured relative to that from H2O2. The translational and rotational energy current of the OH photofragment from PNA has been characterized. A fluorescent emission was also observed and characterized. It is attributed to electronically excited NO2 produced in the PNA photodissociation. A maximum yield of 30% for NO2* production was determined. The intensity of this emission, and a mass spectrometric peak at m/e=33, have been found to be useful means of characterizing the purity of the PNA sample. ¿ American Geophysical Union 1988