The kinetics of chlorination of several phenolic compounds and the corresponding formation of chloroform were investigated at room temperature. For the chlorination of phenolic compounds, second-order kinetics was observed, first-order in chlorine, and first-order in the phenolic compound. The rate constants of the reactions of HOCl with phenol and phenolate anion and the rate constant of the acid-catalyzed reaction were determined in the pH range 1-11. The second-order rate constants for the reaction HOCl + phenol varied between 0.02 and 0.52 M-1 s(-1), for the reaction HOCl and phenolate between 8.46 x 10(1) and 2.71 x 10(4) M-1 s(-1). The rate constant for the acid-catalyzed reaction varied between 0.37 M-2 s(-1) to 6.4 x 10(3) M-2 s(-1). Hammett-type correlations were obtained for the reaction of HOCl with phenolate (log(k) = 4.15-3.00 x Sigmasigma) and the acid-catalyzed reaction of HOCl with phenol (log(k) = 2.37-4.26 x Sigmasigma). The formation of chloroform could be interpreted with a second-order model, first-order in chlorine, and first-order in chloroform precursors. The corresponding rate constants varied between k > 100 M-1 s(-1) for resorcinol to 0.026 M-1 s(-1) for p-nitrophenol at pH 8.0. It was found that the rate-limiting step of chloroform formation is the chlorination of the chlorinated ketones. Yields of chloroform formation depend on the type and position of the substituents and varied between 2 and 95% based on the concentration of the phenol.