What amount of current is usually very painful and can lead to unconsciousness?

The amount of current that is typically very painful and can lead to unconsciousness falls within the range of 25 to 50 milliamperes. This range is particularly significant in the context of electrical safety, as exposure to currents in this level can cause severe physiological reactions. At approximately 10 milliamperes, individuals may begin to feel a painful shock and muscle contractions, and at currents near 20 milliamperes, the risk of loss of muscle control becomes greater. However, as the current reaches 25 to 50 milliamperes, it not only induces substantial pain but can also lead to involuntary muscle contractions that may interfere with breathing and possibly result in cardiac arrest or unconsciousness. Therefore, the risk associated with this range of current is heightened, making it crucial to recognize and understand its hazards in settings where electrical currents are present.