Maintenance activities present some of the highest injury risks in industry.

Lock Out, Tag Out, Try Out (LOTOTO) procedures prevent machinery or equipment from being accidentally energised during maintenance or repair.

Isolation duties are supported by the Provision and Use of Work Equipment Regulations 1998 (PUWER) and the Health and Safety at Work etc. Act 1974.

LOTOTO ensures that:

  1. Energy sources are identified
  2. Equipment is isolated
  3. Locks and tags are applied
  4. Zero energy is verified

LOTOTO procedures should integrate directly with your Permit to Work system.

If maintenance requires access at height or entry into tanks or vessels, additional controls under the Working at Height Regulations 2005 and Confined Spaces Regulations 1997 may apply.

Reece Training can support your organisation in implementing practical isolation procedures that align with UK legal duties and operational realities.

What Does LOTOTO Involve?

  1. Identify all energy sources (electrical, hydraulic, pneumatic, mechanical)
  2. Isolate them
  3. Apply locks
  4. Apply warning tags
  5. “Try out” to verify zero energy

Real-World Risk

Many serious injuries occur during maintenance rather than normal operation because the equipment unexpectedly starts.

Common failures include:

  • Relying on control panels instead of full isolation
  • Failing to identify stored energy
  • Not verifying isolation
  • Multiple contractors working without coordination

A structured LOTOTO procedure removes ambiguity and protects everyone involved.

Below are three real-world examples in which a strict LOTOTO procedure was not followed.

1. Waste and Recycling Company - Worker Injured During Machine Cleaning (2023)

What happened:

An employee was seriously injured while cleaning a waste picking line at a recycling facility when machinery was inadvertently restarted and trapped him. The worker suffered a fractured shoulder, torn ligaments, and a broken finger.

What went wrong:

  • The machine had not been properly isolated before cleaning work began.
  • The isolation procedure was not correctly implemented or monitored, allowing a supervisor to restart the line while a worker was inadvertently still performing cleaning tasks.

Outcome:

The company was fined £270,000 after pleading guilty to breaching the Health and Safety at Work etc. Act 1974. HSE highlighted the importance of robust movement isolation and lock-off procedures before any maintenance or cleaning work. 

Official source: Waste and recycling company fined after worker injured cleaning machinery.

Key Lesson:

Always ensure full hazardous energy isolation and verification before any maintenance, cleaning or inspection work and continually monitor compliance.

2. Conveyor Maintenance - Fatal Accident Highlighting Isolation Failures

What happened:

In a notable enforcement outcome, TATA Steel (UK) Ltd was fined after a contractor was crushed by a conveyor system when it was not fully isolated during maintenance work. The conveyor moved unexpectedly, resulting in fatal injuries for the contractor.

What went wrong:

  • The conveyor system was not adequately isolated from all energy sources before maintenance commenced.
  • The underlying cause was a failure to apply basic isolation and lock-off controls, even though these are long-established safety expectations.

The regulator’s analysis identified this incident (among others in 2025) as a key example of how failing to implement proper energy isolation and LOTOTO principles leads to severe consequences. 

Outcome:

TATA Steel was fined £1.5 million plus costs after pleading guilty to breaches of general duty legislation.

Official source: TATA Steel fined £1.5 million after father-of-three crushed to death at Port Talbot plant – HSE Media Centre 

Key Lesson:

Isolation and lock-off procedures are fundamental, not “optional” for any maintenance activity on industrial equipment.

3. Offshore Isolation Failures (2025)

What happened:

The HSE published an investigation summary highlighting multiple isolation failures on offshore installations, in which improper implementation of isolation procedures increased the risk of unintended hazardous releases, including gas leaks and fires.

What went wrong:

  • Isolation procedures were found to be inadequate or not fully followed in practice.
  • Risk assessments frequently failed to identify all sources of trapped energy (e.g., fluids, pressure).
  • Method statements and isolation designs did not always reflect actual plant conditions, resulting in incorrect isolation actions.

Outcome:

While this summary is not tied to a single prosecution, it demonstrates a systemic offshore isolation compliance issue, and the regulator emphasised that isolation failures are a persistent cause of significant incident risk. 

Official source: Offshore process isolation failures present a major accident hazard risk

Key Lesson:

Energy isolation procedures must be designed, verified, and actively followed, especially in complex systems where stored-energy risks may be hidden.

Summary: LOTOTO Failures in the UK

These UK examples show that LOTOTO/safe isolation failures often share common causes:

  • Incomplete isolation of machinery before cleaning or maintenance
  • Restarting equipment without ensuring all workers are clear
  • Poor hazard identification and energy source verification
  • Lack of verification that isolation measures are effective
  • Failures in communication between supervisors and workers

What These Cases Teach Us

  • Lock-Out/Tag-Out/Try-Out (LOTOTO) must be fully implemented, not just documented on paper.
  • Verification (“Try-Out”) after isolation is essential to ensure zero energy.
  • Clear procedures, training, and supervision are critical to ensure isolation systems work as intended.
  • Monitoring and auditing adherence to isolation controls helps prevent repeat incidents.

Providing training to those who supervise or implement LOTOTO systems within an organisation is critical to building effective, sustainable isolation systems.

Final Thought: Compliance Is the Baseline - Safety Is the Goal

At Reece Training, working at height, confined spaces, permit systems and LOTOTO all have one thing in common:

They exist because the risks are serious and the consequences of getting it wrong are life-changing. A strong safety culture doesn’t just aim to meet legal requirements. It aims to ensure that everyone goes home safely at the end of the day.

If your organisation requires practical LOTOTO training to help embed safe systems of work into the workplace, review our range of training and consultancy packages and contact us today at sales@reecetraining.co.uk.

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