The solubility of atrazine, 2,4-dichlorophenoxyacetic acid, pentachlorophenol and 2,2＇,3,3＇,4,4＇-hexachlorobiphenyl were determined at temperatures ranging from 313 to 413 K and pressures ranging from 150 to 450 bar in supercritical CO2. In all cases (except the 150 bar result for atrazine), raising the temperature at constant pressure substantially increased solubilities (typically 1-2 orders of magnitude, with the largest enhancements occurring at higher pressures) despite the decrease in CO2 density. Comparisons of 2,2＇,3,3＇,4,4＇-hexachlorobiphenyl solubilities with literature results at 313 K were reasonable. Correlation of the results shows good self-consistency of the data obtained, as well as giving equations for obtaining solubilities under any pressure or temperature conditions within the experimental range.