Electricity and Control March 2016

HAZARDOUS AREAS + SAFETY

Understanding Lock Out/ Tag Out procedures

Hayley Arnesen, North Safety Products

At any given time in South Africa, three million workers are exposed to the hazards posed by volatile energies such as electricity, gas, fluids or steam, which are contained in various types of machinery undergoing routine servicing and maintenance.

C raft workers, electricians, machine operators, and labourers are injured and even killed on the job from exposure to hazardous energy. The most effective means of minimising these risks is by securing and controlling the energy sources with an effective Lock-Out/Tag-Out (LOTO) system. A LOTO system prevents the unexpected start-up or release of stored energy by securing a padlock to a clamp in order to lock the machine being serviced or maintained. After being locked, a tag is placed on the machine to indicate that it should not be turned on. LOTO systems are used in industry and research settings to en- sure that dangerous machines are properly shut off and not started up again prior to the completion of maintenance or servicing work, in order to avoid danger. An industrial machine may contain hazards such as hot fluids, moving presses, blades, propellers, electrical heaters, conveyor belts with pinch points, moving chains and ultraviolet light, to name a few. The lack of a LOTO system, or improper handling of the system, may result in injuries that include electrocution, burns, crushing, cutting,

laceration, amputation, or fracturing of body parts. The unexpected start-ups can also cause extensive damage to the machinery itself, adding to the expense of equipment repairs and replacement to the total cost involved. Disconnecting or making the equipment safe involves the removal of all energy sources and is known as isola- tion. The isolation procedure generally includes the following tasks: • Announcing the shut-off • Identification of the energy source/ sources • Isolation of the energy source/ sources

• Locking and tagging of the energy source/ sources • Proving that the equipment isolation is effective

After informing employees of the LOTO procedure, the equipment due to be repaired or serviced must be at a zero-energy state before any work can be undertaken. This procedure starts by locating the energy source. It is vitally important to identify the true source of energy and to locate backups such as generators. A flow diagram or schematic often assists in tracing energy to the source.

March ‘16 Electricity+Control

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