Common 'Lockout-Tagout'Operational Errors That May Jeopardise Worker Safety
In many industrial facilities, 'Lockout-Tagout'(LOTO) procedures have become an integral part of the safety system. Organisations may have established written procedures, employee training programmes, and equipped their sites with various locking devices.
However, during safety audits, inspectors frequently find that the biggest problems do not stem from a lack of equipment. Rather, these errors usually arise from minor oversights in day-to-day operations – such as taking shortcuts, unclear responsibilities, or failure to follow operating procedures correctly.
Only when every step is carried out correctly can the lockout procedure truly be effective. Below are five common LOTO errors frequently identified during workplace safety inspections.
1. Failure to identify all energy sources
One of the most common errors in Lockout/Tagout (LOTO) procedures is the failure to identify all energy sources comprehensively.
Many staff members understand the need to disconnect the power supply, but machinery typically contains multiple energy sources, including:
· Electrical energy
· Hydraulic pressure
· Pneumatic pressure
· Stored mechanical energy
· Thermal energy
· Chemical energy
· Gravity or suspended loads
During audits, it is often found that whilst the main circuit breaker for a piece of equipment has been locked out, another energy source remains active.
For example, a maintenance technician may have disconnected the power supply to a hydraulic press but failed to release the residual hydraulic pressure within the system. Although the equipment may appear safe, accidental movement could still occur.
A correct 'Lockout/Tagout' (LOTO) procedure should involve a comprehensive energy assessment before any maintenance work commences.
2. Use of unsuitable lockout devices in operational scenarios
Another common issue identified during inspections is the use of unsuitable or makeshift locking devices.
Some facilities may use generic padlocks, cable ties or temporary solutions instead of dedicated LOTO devices. Whilst these methods may appear convenient, they may fail to provide reliable protection.
Professional locking devices are specifically designed for safety applications, including:
· Circuit breaker lockout devices
· Valve lockout devices
· Pneumatic lockout devices
· General-purpose lockout devices
· Safety padlocks
· Lockout hasp
Each device should be matched to the equipment being isolated.
For example, valve lockout devices should effectively prevent valve operation, rather than merely covering the handle. Safety padlocks should be easily identifiable and used exclusively for LOTO purposes.
Using the correct devices is not just a matter of compliance-it also directly affects whether energy isolation measures remain effective.
3. Poor communication between authorised personnel and affected personnel
LOTO procedures involve different categories of staff.
Authorised personnel are responsible for locking out equipment and carrying out maintenance work.
Affected personnel operate equipment or work in the vicinity of it, but do not carry out the locking-out themselves.
A common issue identified during audits is poor communication between these two categories of staff.
For example:
· Operators are not notified before equipment is taken out of service
· Staff are unaware of why the equipment has been locked out
· Correct lock handover procedures are not followed during shift changes
· Staff remove locks without authorisation
The success of a LOTO programme depends on clear communication. All relevant personnel should be aware of:
· Who has fitted the locks
· Why the equipment has been isolated
· When normal operations may resume
Locks are a physical barrier, but communication is the key process that makes this barrier effective.
4. Failure to verify after locking out
Locking out does not automatically guarantee that energy is at zero.
One of the most commonly overlooked steps in the LOTO process is energy verification.
After isolating the equipment, personnel should confirm the following:
· The machine cannot be started
· Electrical energy has been completely disconnected
· Stored energy has been released
· Pressure has been released
· Moving parts have been secured
A common mistake is to assume that switching the isolating switch to the 'OFF' position means the machine is safe.
Experienced safety professionals know that verification is the final confirmation before work commences.
The simple rule is:
Lock it, Tag it, Test it, Then Work on it.
5. Inadequate training and a lack of regular reviews
Many companies provide LOTO training when employees join the organisation, but fail to provide ongoing refresher training.
Over time, employees may forget operating procedures, new recruits may not receive sufficient practical training, and existing operating procedures may no longer be applicable to updated equipment.
Safety audits often reveal the following issues:
· Employees are unable to explain LOTO operating procedures
· Lack of lockout instructions for specific equipment
· Outdated energy control procedures
· Lack of annual LOTO reviews
LOTO is not a one-off training exercise, but rather a process requiring continuous improvement.
Regular checks, refresher training and updates to procedures help ensure that safety measures remain effective at all times.
Building a Stronger LOTO Safety Culture
To successfully implement a Lockout/Tagout (LOTO) programme, simply purchasing safety locks and locking devices is not enough.
It requires:
· Correct hazard identification
· Suitable locking equipment
· Clear operating procedures
· Employee awareness
· Regular inspections
Most LOTO errors are not caused by complex issues. They are often the result of simple safety steps being overlooked during day-to-day operations.
By identifying these common errors and improving the overall lockout system, organisations can reduce risks in the workplace and create a safer working environment for everyone.
