Some types of heavy equipment used in construction can store energy. The unexpected release of such energy, or the unauthorized startup of the machinery, can pose a hazard to you if it occurs when you are working on the equipment or otherwise not ready for the startup or discharge. 

According to the Occupational Safety and Health Administration, lockout and tagout procedures are in place to protect you from injuries that can occur due to unexpected discharge of energy or startup of the machinery. However, though the goal is the same, the two procedures work in different ways. 

Tagout 

Before you maintain or service a piece of construction equipment, a tagout procedure requires you to post a warning on the device. This informs others that you are working on the equipment and they must not re-energize it. 

Tagging a piece of equipment out offers a relatively low level of protection. First, tagout devices do not prevent the re-energization of the equipment, and furthermore, they are relatively easy to remove or ignore. However, tagout can combine with another procedure, such as a lockout, to provide more protection. 

Lockout 

Lockout offers more protection than a tagout procedure. A lockout device prevents the accidental or unauthorized discharge of energy or startup of the machinery. It works by holding the equipment safely in the off position. Removal of the device or override of the safeguard is not possible without an unlocking mechanism such as a key. 

Your employer should have tagout and/or lockout procedures in place to protect you and your co-workers from injuries that may occur due to unexpected startup of machinery or release of energy.