Figure 7.

Radical scavengers and reactions. After exposure to UV-A, O₂ is converted into ¹O₂. The ¹O₂ is eliminated by sodium azide (NaN₃), which acts as a scavenger. After exposure to UV-A/UV-C or electrons (e⁻), O₂ is converted into the superoxide anion radical (·O₂⁻), which is eliminated by superoxide dismutase (SOD). ·O₂⁻ is converted into H₂O₂ after reaction with e⁻ + 2H⁺. H₂O₂ is eliminated by catalase. After the reaction with e⁻ + H⁺, H₂O₂ is converted into a hydroxyl radical (·OH). ·OH is eliminated by dimethyl sulfoxide (DMSO). After the reaction with e⁻ + H⁺, ·OH is converted into H₂O. After the reaction with NO, O₂⁻ is converted into ONOO⁻, which is eliminated by uric acid. ONOO⁻ is then converted into ONOOH after reaction with H⁺, and ONOOH is eliminated by ascorbic acid.