Although reactive halogen species (X*=X<sup>●</sup>, <sup>●</sup>X<sub>2</sub><sup>−</sup>, X<sub>2</sub> and HOX, where X=Br, Cl, or I) are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH<sub>2</sub>=CHCH<sub>2</sub>OH) as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq). In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br<sup>−</sup>). In this paper, we discuss method development for solutions containing chloride (Cl<sup>−</sup>) alone, and for solutions containing both bromide and chloride.