Record Display for the EPA National Library Catalog
RECORD NUMBER: 48 OF 265
|OLS Field Name||OLS Field Data|
|Main Title||Determination of rates of reaction in the gas-phase in the troposphere : theory and practice. 3. Rate of indirect photoreaction /|
|CORP Author||Environmental Protection Agency, Washington, DC. Office of Toxic Substances.|
|Publisher||U.S. Environmental Protection Agency, Office of Toxic Substances,|
|Subjects||Tropospheric chemistry--Mathematical models. ; Hydroxyl group--Environmental effects. ; Air--Pollution--Mathematical models.|
|Additional Subjects||Reaction kinetics ; Atmospheric chemistry ; Photochemical reactions ; Air pollution ; Hydroxyl radicals ; Molecular structure ; Chemical reactivity ; Troposphere ; Error analysis ; Oxidation ; Organic compounds ; Mathematical models ; Structure reactivity relationships ; Toxic Substances Control Act|
|Collation||238 pages ; 28 cm|
The report describes the development of structure/reactivity (S/R) relationships of Atkinson for the estimation of the 2nd-order rate constant k(OH) for the reaction of OH radicals with organic chemicals in the troposphere. These S/R relationships were used to estimate k(OH) at 298 K of 405 chemicals covering a variety of classes and compares them with the experimental values (% Error). Of the 405 chemicals, 20 had a % error > +100 and were omitted in the analyses. For the 385 remaining chemicals, the average % error ranged from +21 to -19. One hundred fifty-four chemicals were not used by Atkinson to derive the parameters in the S/R relationships and, therefore, were good candidates to test the validity of the S/R relationships. The average percent error of the 154 chemicals ranged from +24 to -20, thereby confirming the S/R relationships. A discussion is given on the estimation of the half-life of a chemical in the troposphere from k(OH) and the average OH concentration. The report represents the technical support document for a test guideline which can be used under section 4 of the Toxic Substances Control Act.
"EPA 700-R-92-002." Includes bibliographical references (pages 205-221). "3. Rate of indirect photoreaction: technical support document for Test guideline section 796.3900. Structure/reactivity relationships for estimating the second-order rate constant for the reaction of an organic chemical with hydroxyl radicals." Microfiche.