What constitutes potentially hazardous voltage?

Potentially hazardous voltage is defined with respect to the level of voltage that can pose a risk to human safety or cause harm to electrical systems and equipment. In this context, DC voltages over 60 V are recognized as potentially hazardous because they can cause electric shock, burns, or even fatal accidents if contact is made. Similarly, all AC voltages are considered potentially hazardous, given that alternating current can cause muscle contractions and a greater risk of arrhythmias in the heart compared to direct current.

The classification of DC voltages above 60 V and all AC voltages as hazardous reflects the inherent risks they pose in practical applications. Systems operating at these voltage levels require stringent safety measures and proper insulation to mitigate risks to personnel and equipment. This is why the selected choice appropriately identifies the threshold for what is regarded as potentially hazardous voltage in electrical safety standards.

In contrast, other options either misclassify the voltage thresholds or do not adequately encompass the types of current that are dangerous, making them less accurate in defining potentially hazardous voltage.