The mechanical devices that can physically prevent the transmission or release of energy are called ________________

• A. Energy isolation devices
• B. Tagout devices
• C. Lockout devices
• D. Interlocks

Answer: (A)

Energy isolation devices are the hardware that physically stops energy from reaching equipment. They include items like disconnect switches, valve shutoffs, or other barriers that, when engaged, prevent electrical, hydraulic, pneumatic, chemical, or thermal energy from being transmitted to the machine. This is how energy control is actually achieved in practice, ensuring workers aren’t exposed to unexpected energization or release during maintenance. Tagout devices are used to indicate that a machine is locked out and to warn others, but they don’t themselves stop energy transfer. Lockout devices are the locking components that secure an energy isolation device in a safe position, but the term we’re describing refers to the devices that physically prevent energy transmission. Interlocks are automatic safety mechanisms that can prevent operation under certain conditions, but they’re not the general category for physically blocking energy transfer.