Caption title. "Dec. 1987." At head of title: Project summary. Distributed to depository libraries in microfiche. "EPA/600-S3-87-033."

A series of environmental chamber experiments and computer model simulations were carried out to assess the atmospheric ozone formation potential of the representative heatset printing oils Magie-47 and Magie-470 relative to that of ethane. n-Pentadecane, a representative major constituent of these oils, was also studied. The results showed that n-pentadecane and the printing oils tend to slow down the initial rate of ozone formation in NOx- air irradiations, but they also caused higher final ozone yields in some surrogate-NOx-air experiments. The results of these experiments were used to test current models for the reactivities of ethane and n-pentadecane. The model predictions fit the results of most of the experiments within the experimental uncertainty, though some discrepancies were observed. It is unclear whether the discrepancies are due to problems with the mechanism or to experimental difficulties. The model was used to estimate the reactivities of ethane and n-pentadecane for several idealized model scenarios representing urban air pollution episodes. The predicted atmospheric reactivities of n-pentadecane and the printing oils relative to ethane were found to be highly dependent on the conditions of the model scenario. Thus, decisions on whether regulation of emissions of printing oils is beneficial in reducing atmospheric ozone must take into account the range of conditions of the airsheds into which they are emitted.