COMPUTER ESTIMATION OF THE ATMOSPHERIC GAS-PHASE REACTION-RATE OF ORGANIC-COMPOUNDS WITH HYDROXYL RADICALS AND OZONE

The Atmospheric Oxidation Program (AOP) is a computer Program constant for the atmospheric, gas-phase reaction between photochemically produ ced hydroxyl radicals (OH) and organic chemicals. It also estimates th e rate constant for the gas-phase reaction between ozone and olefinic/ acetylenic compounds. AOP, which uses estimation methods developed by Atkinson and co-workers, estimates more accurate rate constants than t he PCFAP (Fate of Atmospheric Pollutants) program that was part of the U.S. EPA's Graphical Exposure Modeling System (GEMS). Due to its supe rior predictive ability, the EPA is currently using AOP to evaluate th e atmospheric fate of compounds defined under Sections 4, 5 and 6 of t he Toxic Substances Control Act (TSCA).