Final answer:
OSHA requires the use of GFCIs for electrical tools on a job site to prevent electric shock by interrupting the circuit if a leakage current greater than 5 mA is detected, indicating a potentially hazardous situation.
Step-by-step explanation:
The question addresses whether OSHA requires the use of GFCIs for electrical tools on a job site. The answer is true. GFCIs are required because they are crucial safety devices that detect imbalances between the live/hot and neutral currents. If a leakage current greater than 5 milliamperes is detected, which could indicate the current is following an unintended, and potentially hazardous, path such as through a person's body, the GFCI interrupts the circuit to prevent electric shock.
Plastic insulation on wires prevents both thermal hazards and shock hazards by insulating live/hot wires. Contrastingly, ordinary circuit breakers and fuses are ineffective in preventing shocks because they are designed to protect against overcurrents that can cause fires, not minor current leaks responsible for most electric shocks.
A GFCI may trip if the live/hot and neutral wires are significantly different in lengths because the difference can cause an imbalance in currents that the GFCI detects as a potential ground fault. This function underscores the sensitivity and importance of GFCIs in maintaining electrical safety.