The generation of short-lived .OH radicals upon reaction of H
with individual filter sizes using different wire type and time periods after generation of fume. Open symbols represent stainless steel while filled symbols are mild steel wire. ESR spectrum recorded 3 min after reaction was initiated in PBS (pH 7.4), 1 mM H2O2 and 100 mM DMPO. ESR settings were; center field, 3385 G; scan width, 100 G; time constant, 40 msec; scans, 5; modulation amplitude, 1 G; receiver gain, 2.5 × 104; frequency, 9.793 GHz; and power, 63 mW.