Redox proteomics workflows are applied widely in discovery and targeted studies of the oxidative mechanisms underlying physiological and pathological processes. These workflows involve direct labeling of oxidized species with selective chemical probes or tag-switch methods, blocking of reduced thiol species (-SH) with the goal of preventing undesired reactions at the time of lysis or during the proteomics sample processing procedures, enrichment of labeled proteins, and mass spectrometry analysis. We will present recent advancements on in vitro labeling of protein sulfenylation (-SOH), new reagents for selective blocking of reduced -SH species, imaging using -SOH probes, and the application of these to address critical questions in biology and medicine related to environmental exposure to stressors.