What is the main distinction between lockout and tagout?

The main distinction between lockout and tagout lies in their functionality and purpose, which is precisely captured by the answer that lockout physically prevents energy release, while tagout warns against it. Lockout involves using a device that physically secures an energy-isolating mechanism to ensure that machinery cannot be operated while maintenance or servicing is being performed. This provides a direct means of ensuring that the equipment cannot be energized inadvertently, thus safeguarding workers from potential hazards associated with unexpected machine start-ups.

In contrast, tagout serves as a warning system. It involves placing a tag on the energy-isolating device, indicating that the equipment must not be operated. While tagout communicates that an operator should not energize the equipment, it does not physically prevent the release of energy. Therefore, if a person were to remove the tag, they could potentially put the equipment back into service without realizing that someone is still working on it. This fundamental difference emphasizes the enhanced safety that lockout provides over tagout, making it essential for certain high-risk operations.