Concern for ELECTRIC BURN effects may arise with d.c. or at high frequencies (for example, above 30kHz for 3.5mA TOUCH CURRENT). At lower frequencies, startle-reaction and letgo-immoblization will be the dominant considerations. Where there is such a concern, the unweighted r.m.s value of TOUCH CURRENT shall be measured (figure 3), in addition to measurement for either startle-reaction (figure 4), or inability to let go (figure 5).