Audits, Occupational Safety

Maintenance safety with lockout-tagout

Put a stop to risks: Prevent accidents and work safely with LOTO.

6 minutes09/11/2023

Tragic workplace accident: An electrician is assigned to inspect the circuity of a production facility. He begins by shutting down all systems and entering the facility. During the inspection, another person, unaware of the ongoing maintenance, enters the production area and reactivates the plant. This causes electric current to surge through the wires, resulting in an electric shock to the electrician inside the facility. This incident could have been avoided with the implementation of the lockout-tagout system.

Unfortunately, such incidents are not isolated. Data from the U.S. Bureau of Labor Statistics' Census of Fatal Occupational Injuries reveal the precarious nature of maintenance work. In the United States, maintenance workers rank 21st among the most dangerous occupations, with a fatal injury rate of 13 per 100,000 workers. Among the most common fatal injuries are those involving contact with objects and equipment.

EU-OSHA findings paint a similar picture. Approximately 15% of all accidents in countries such as Belgium, Finland, Spain, and Italy can be attributed to maintenance operations. Looking across different European countries, statistics from 2006 show that maintenance operations accounted for around 10-15% of all fatal accidents.

There are many hazardous associated with maintenance work that can cause accidents of varying severity. These hazards range from electrical currents, hydraulic power, and steam to electromagnetic radiation and hazardous chemicals. As a responsible manager or occupational safety specialist, ensuring maintenance safety should be a top priority, especially when working with contractors. This article will provide you with insight into the skillful use of simple lockout-tagout systems – a cornerstone of preventive safety.

Lockout-tagout: What is it?

Lockout-tagout (LOTO) is the process of shutting down, locking up, and tagging a piece of equipment or machinery. This maintenance safeguard prevents accidental or unintentional re-energization – especially when working with external companies.

First: Lockout

The basic principle of the lockout-tagout procedure is quite simple: The technician performing the maintenance work first shuts down the respective system or machine. Then comes the lockout. More specifically: The technician locks the power mechanism of the system or machine with a LOTO padlock. This ensures that it cannot be restarted accidentally.

Next: Tagout

The next step is tagout. This is where the technician labels the padlock with a LOTO tag that provides all the necessary information about the lockout

  • Why was the machine or system locked out? 
  • When was the shutdown performed? 
  • How long is the lockout required? 
  • What work is being performed on the system or machine? 
  • Who is responsible for the lockout? 

Lockout-tagout-tryout: LOTOTO

Locking and tagging are only part of the lockout-tagout procedure. Tryout must also be included. This verifies the lockout

  • Is the implemented LOTO lockout effective? 
  • Is the lockout-tagout padlock properly secured? 
  • And is there absolute certainty that the system or machine cannot be re-energized? 

Tryout is crucial

If you look closely, the correct abbreviation for the system is: LOTOTO. Tryout is absolutely essential to ensure that the technician can perform their work with true protection. Subsequent employees do not have the possibility to accidentally activate the system or machine during the lockout, thus releasing dangerous energies. Furthermore, they will be fully informed of the reason and duration of the lockout. This allows them to plan their time more effectively. In addition to safety, the lockout-tagout-tryout system increases efficiency and productivity in the plant.

Multiple lockouts

But what if more than one person is working on the system or machine? This is not uncommon. To continue with our previous example: After the first technician has started their work inside, another person shows up who also needs to do something on the shutdown system. 

Their safety also depends on the system remaining shut down. So, they add an additional padlock and tagout marking to the existing LOTO padlock. When the first technician returns to remove their own lockout-tagout padlock, they see the second LOTO padlock, indicating that someone else is working on the deactivated system. This immediately informs them that re-energizing is still not permitted. 

This allows the LOTO system to be expanded as needed and provides a high level of safety even for complex tasks, regardless of the number of people involved.

The LOTO padlock

A traditional hardware store padlock is not suitable for maintenance safety. The reason: The LOTO padlock must be designed for the specific conditions of its application. For example, different locks are used in sterile environments than in the foundry industry. These padlocks vary in material and design to suite the local conditions. It's important to consider the requirements and select specific lockout devices. That is the key to increased safety.

Tips and tricks for a LOTO padlock

  • Key insertion

    The key to a LOTO padlock should not be removable when the lock is open. This precaution supports the tryout process and prevents ineffective lockout.

  • Emergency key

    It is equally important that a lockout-tagout padlock can be opened quickly in the event of an emergency. A master key is used for quick release – separate from the regular key.

  • Color coding

    The use of color-coded LOTO padlocks can further enhance safety and simplify work processes. Color coding can be used to quickly identify who is currently working on the system. For example, blue padlocks can be assigned to external workers, while green padlocks can be assigned to in-house technicians. Alternatively, colors can be designated for specific machines. 

    Although color codes provide information from the tagout tag, it doesn't mean that tagout can be omitted. Marking with a tagout tag is essential and should never be overlooked.

The LOTO board station

Everything within reach? With the lockout-tagout board station, the answer is "Yes." It holds everything that makes up the lockout-tagout system: LOTO padlocks, LOTO tags, and other tools such as valves or switches. The LOTO board station is a wall board on which the necessary tools are hung on hooks. Lockout-tagout stations are also available as cases or hanging cabinets. The most important aspect of the selection is that the LOTO station should be highly visible and easily accessible to employees.

Before setting up the station, managers and safety officers should clarify how the lockout-tagout process will be organized. In addition to responsibilities, specific procedures and color codes should be established. Based on these guidelines, they can then select the appropriate LOTO station and adjust it as needed.

Lockout-tagout checklist

Have you thought of everything? Follow our checklist to make sure your lockout-tagout system is comprehensive and that you haven't overlooked any safety issues.

Inspect machines and equipment

  • Which machines and equipment are in the plant? 
  • Do machines and equipment have hazardous energy sources? 
  • What potential hazards can be caused by the machines or equipment?
    • Electricity
    • Mechanical forces 
    • Pneumatic energy 
    • Steam 
    • Air 
    • Heat 
    • Cold 
    • Chemicals 
    • Radiation 
  • Are there hazard assessments? 
  • Are operational instructions derived from the risk assessments? 
  • Are the machines and equipment suitable for the lockout-tagout system? 
  • Which shutdown points on the machine or equipment are suitable for the LOTO system? 
  • Are there special conditions to consider for certain machines?

Define LOTO standards 

  • Have those responsible defined a standardized LOTO procedure? 
  • What are the responsibilities within the standardized LOTO procedure? 
  • Is there a defined process for issuing LOTO permits? 
  • Is there a defined LOTO training process? 
  • Have responsible personnel received appropriate training? 
  • Have those responsible documented the LOTO standards in writing? 
  • Have specific LOTO color codes been established by those responsible? 
  • Are all employes aware of the LOTO standard?

Consider key details

  • How is the implementation of the LOTO system managed in cooperation with external companies? 
  • How is independent unlocking of LOTO padlocks handled in an emergency? 
  • How does the lockout-tagout procedure work during shift changes? 
  • What happens if a LOTO key is lost? 
  • Does the lockout-tagout station match the with existing conditions? 
  • Does the lockout-tagout equipment meet all technical requirements

Conclusion: Make maintenance safety a priority with LOTO

Tragic maintenance accidents can and should be prevented. The lockout-tagout system literally puts hazards out of reach. It significantly improves maintenance safety, measurably reduces accident rates, and also sends a powerful message. Prominently displayed, a lockout-tagout station communicates from afar that your company takes its responsibility for employee safety and health very seriously.