Database of second-order rate constants for aqueous phase reaction of organic contaminants with the major oxidants involved in groundwater remediation by In Situ Chemical Oxidation (ISCO)—including permanganate, hydroxyl radical (from activated peroxide), and sulfate radical (from activated persulfate)—plus other comparable oxidants of environmental interest (carbonate radical, chlorine dioxide, and ozone). The data were compiled between 2003 and 2005 by Rachel Waldemer, Jaimie Powell, and other students under the direction of Professor Paul G. Tratnyek at the Oregon Graduate Institute in Beaverton, Oregon, USA. In 2006, a script written by Kaylie Langley was used to make the data available online via an interface that allowed searching by chemical name, CAS-RN, etc. The result was named the “IscoKin” database and was available at http://cgr.ebs.ogi.edu/iscokin/search.php until the server was retired in 2019. In place of IscoKin, we have made all of the data available as a spreadsheet in .xlsx format. The file includes two sheets, the first contains one “recommended” rate constant for each combination of organic compound and oxidant (i.e., one row per compound). The second sheet contains all of the individual rate constants that were compiled (i.e., one row per experimental result). The "best" value is most often an average of the individual values listed in the "All_values_with_references" sheet; but occasionally this value represents a single value, usually the "best" value given in Buxton et al. (1988) “Critical review of rate constants for reactions of hydrated electrons. hydrogen atoms and hydroxyl radicals (•OH/•O-) in aqueous solution” J. Phys. Chem. Ref. Data. 17, 513-886. While the database was checked thoroughly, it still is unlikely to be completely accurate or complete. For critical applications, we recommend tracking down the primary sources (listed in the spreadsheet) and use them for data, conditions, and other caveats. Obviously, we do not accept any responsibility for what anyone does with information obtained from this document. The work was funded by the Strategic Environmental Research and Development Program (SERDP), under grant number ER-1289, titled “Improved Understanding of In Situ Chemical Oxidation”. More details on this work can be found in Part 1 of the final project report, which is located at https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Persistent-Contamination/ER-1289/.