What is the "let-go" threshold for a man receiving an electrical shock?

The "let-go" threshold refers to the minimum amount of electrical current that can cause a person to lose their ability to voluntarily let go of an electrical source due to muscular contractions. For most individuals, this threshold typically falls around 30 mA (milliamps). At this level, the current can induce involuntary muscle contractions strong enough that the person may be unable to release their grip on the source of the shock, leading to prolonged exposure to the electrical current.

Understanding this threshold is vital in the context of safety for electrical work and equipment usage, as exceeding this current significantly increases the risks of serious injury or fatality due to ongoing electrocution. Lower thresholds, such as 5 mA or 15 mA, may have various physiological effects, but they generally do not cause an inability to let go of the source, allowing for instinctual reactions to occur. Meanwhile, currents at or beyond 50 mA can be lethal, reinforcing the importance of recognizing the let-go threshold as a critical safety metric.