An Alternative Approach to Photochemical Ozone Creation Potentials Applied under European Conditions

ABSTRACT

Photochemical ozone creation potential (POCP) values for 83 different volatile organic compounds (VOCs), including CO and CH₄, were calculated under different environmental conditions representative for Europe. These calculations show that variations in POCP values are large between different types of chemical environments and that POCP values for VOCs should be presented as ranges instead of single values. POCP ranges are based on the extremes of the POCP values and are defined with the intention to include all POCP values an individual VOC will obtain in any European environment where O₃ formation is of environmental concern. The POCP ranges indicate large differences in O₃ production between individual VOCs, which justifies the use of this ranking scale instead of treating all VOCs as a homogeneous group of species in abatement strategies.

Both the average O₃ production over 96 hr and the maximum contribution to the O₃ concentration were studied. The most efficient O₃ producers were found to be iso-prene, 2-methyl-2-butene, and acrolein. As a group, the alkenes are the most potent O₃ producers, followed by higher alkanes and then the aromatics. The calculated values show a good agreement with previously calculated POCP values under northern European conditions.