An analysis of the aeronomic conditions related to oxygen photodissociation has been made by including updated absorption cross sections in the region of the Herzberg continuum at wavelengths greater than 200 nm. This analysis demonstrates that there is a decrease in the production of odd oxygen atoms compared with that obtained by using the O2 cross sections adopted before 1980. Quantitative results show that the photodissociation frequency J(O2) cannot be greater, at mesospheric and stratopause levels, than about 5 × 10-10 s-1 for the 200-240 nm interval. The possible errors (± 10%) in these O2 photolysis rates decrease with decreasing altitudes to reach isophotolytic levels (± 0%) in the middle stratosphere, from about 25 to 30 km for increasing solar zenith angles, respectively. In the lower stratosphere, at 20 km and below, there is a rapid increase in the computed errors where the transmittance is less than 10-2. Fuller information will be obtained after an estimation of the possible errors associated with uncertainties in the absorption cross sections of ozone molecules.