||P.719 bottom paragraph: "Some of the reduction products of oxygen are of a free-radical nature, having a free electron (e.g., the superoxide anion radical and the hydroxyl radical), whereas hydrogen peroxide, the two-electron reduction product, is not a radical and as such is a chemically stable molecule. Electronically excited states comprise singlet molecular oxygen
and excited carbonyl compounds, which are also nonradicals. Further biologically important reactive species are chlorine and bromine species such as hypohalous acids, hypochlorite, and chloramines. Detailed chemical properties of these molecules have been compiled in textbooks and reviews. Suffice it to say here that the chemical reactivities of the various reactive species shown in Table 2 vary by up to 11 orders of magnitude when assayed against a given target, an example is
shown in Table 3."