Workplace Solutions Facility safety Hazard communication Lockout/tagout Machine guarding

An effective lockout/tagout program

How can you ensure your employees are following the lockout/tagout process?


Responding is Nick Walton, senior director of interlock solutions, Kirk Key Interlock Co. LLC, North Canton, OH.

Lockout/tagout programs are essential for ensuring the safety of workers who service or maintain machines and equipment. The unexpected startup or release of stored energy from these machines can result in serious injury or even death. Therefore, the implementation of an effective LOTO program isn’t just a regulatory requirement but a critical component of workplace safety.

Here are seven steps to follow to create an effective LOTO program:

1. Identify energy sources
The first step in implementing a LOTO program is to identify all equipment that poses a hazard during maintenance or servicing. This involves recognizing all potential energy sources that need to be controlled, which can include electrical, mechanical, hydraulic, pneumatic, chemical and thermal energies. Each source presents unique challenges and requires specific methods to effectively isolate and lockout.

2. Develop LOTO procedures
Once all energy sources are identified, the next step is to develop comprehensive LOTO procedures. These procedures should detail the steps required to shut down, isolate, block and secure machines to control hazardous energy. The procedures must be clear, machine-specific and understandable to all employees.

3. Select LOTO devices
Selecting proper LOTO devices is crucial. These devices must be durable, standardized and substantial enough to prevent removal without the use of excessive force or special tools. Devices can range from padlocks to hasps, and they must be singularly identified; that is, one key or combination should open only one lock to prevent unauthorized removal.

4. Train employees
Training is a pivotal aspect of a LOTO program. Employees must be educated on the importance of energy control and able to apply, use and remove LOTO devices correctly. They should also be aware of the consequences of not following LOTO procedures.

5. Inspect and audit
To ensure the ongoing effectiveness of LOTO programs, regular inspections and audits must be conducted. This helps in identifying any deviations or inadequacies in the procedures and devices being used. Annual audits are also necessary to reflect any changes in the workplace or to the equipment that could affect LOTO procedures.

6. Enforce and document
Enforcement of the LOTO program is vital. It requires consistent application of the rules and procedures, along with proper documentation. This documentation serves as a record of compliance and as a tool for training and auditing purposes.

7. Promote a safety culture
Promoting a safety culture is integral to the success of a LOTO program. It involves creating an environment where safety is a shared responsibility and following safety procedures is the norm.

Trapped key interlock systems

An alternative to traditional LOTO devices is the trapped key interlock system. This system uses a series of fixed mounted locks and keys that enforce a specific sequence of operations, ensuring hazardous energy sources are isolated before access is granted to a potentially hazardous area or condition. The keys are “trapped” in a sequence of locks, ensuring the lockout process is followed to complete the maintenance or servicing task safely.

There are several benefits of trapped key interlocks:
Enhanced safety: By enforcing a predetermined sequence of operations, trapped key interlocks prevent incidental or unauthorized access to hazardous areas.
Process integrity: They ensure a specific process is followed, reducing the likelihood of human error.
Accountability: With trapped key interlocks, it’s possible to have a record of who accessed the equipment and when, increasing accountability among workers.


The implementation of a LOTO or trapped key interlock system is a proactive approach to managing hazardous energy and ensuring worker safety. By integrating these systems into the workplace, employers can protect their employees from incidents and create a safer work environment. It’s not just about compliance; it’s about commitment to safety and the well-being of every individual onsite.

Editor's note: This article represents the independent views of the author and should not be considered a National Safety Council endorsement.

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