Types of Lockout Tagout Devices and Their Uses

Key Takeaways

Lockout tagout devices help isolate energy sources and prevent the accidental startup of machinery and equipment during maintenance, cleaning, or repair operations
OSHA has established stringent regulations and standards for LOTO procedures and devices to ensure worker safety.
Different types of lockout devices are used for various energy sources, including electrical, pneumatic, hydraulic, and mechanical systems.
Advancements in technology have led to the development of more sophisticated and efficient lockout tagout devices and systems.

What Is the Purpose of a Lockout/Tagout Device?

The purpose of a lockout/tagout device is to physically prevent the release of hazardous energy during maintenance, servicing, or repair work on machines and equipment. It ensures that no one can accidentally start up a machine or release stored energy while someone is working on it. Simply put, using a lockout/tagout device makes sure you go home in one piece.

Yet, too often, I hear excuses like "I’ll just be quick" or "I don’t need it." Let me tell you something—those excuses are pure nonsense. I’ve been in this industry long enough to see what happens when people take shortcuts. In 2020, a worker on a laminator line stopped a conveyor to fix a torn roll of laminating paper but failed to properly lock out the system. Behind him, powered rollers continued to spin, catching a fiberboard slab and crushing him to death.

Sadly, this isn’t an isolated incident. According to the Occupational Safety and Health Administration (OSHA), an average of 85 workers are killed and 364 suffer amputations every year due to uncontrolled hazardous energy. Because the risks are so severe, OSHA has strict regulations in place to ensure lockout tagout devices are used properly and meet industry standards accordingly.

OSHA Requirements for LOTO Devices

OSHA 29 CFR 1910.147 or The Control of Hazardous Energy (Lockout/Tagout), outlines the protective materials and hardware requirements applicable to the various types of lockout tagout devices:

Durability: LOTO devices must be tough enough to withstand the conditions in which they are used. This means they shouldn’t break, corrode, or deteriorate due to exposure to chemicals, heat, moisture, or rough handling.
Standardization: LOTO devices must have a uniform color, shape, or size within the facility so workers can immediately identify them as lockout/tagout devices.
Substantiality: Lockout devices must be sturdy enough that they cannot be easily removed without tools or excessive force. Tags must be strong enough to withstand workplace conditions and should not come off easily.
Identifiability: LOTO devices must be clearly labeled so there is no doubt that they are used for energy control.
LOTO Exclusivity: All LOTO equipment must only be used for lockout/tagout purposes and not for securing toolboxes, lockers, or doors.

The right lock out tag out devices depend on the machinery you operate, the number of workers involved, and the energy sources that need to be isolated. Understanding the different types of lockout tagout devices will help you choose the most effective options for your operation needs.

LOTO Equipment List: Common Lockout Tagout Devices and When to Use Them

Not every lockout tagout device does the same job. A padlock identifies control of the lockout. A valve lockout blocks movement of a valve handle. A breaker lockout prevents electrical re-energization. A lock box controls keys during group lockout. Choosing the wrong device can leave an energy-isolating point exposed, even when the procedure appears complete.

LOTO Device	Primary Use	When to Use It	Selection Criteria
Lockout padlocks	Securing lockout devices in place	Use on breaker lockouts, valve lockouts, hasps, plug lockouts, cable lockouts, and lock boxes	Choose by keying system, shackle length, body material, color coding, and employee identification requirements
Lockout hasps	Allowing multiple workers to lock one isolation point	Use when more than one authorized employee works on the same machine or energy source	Confirm the hasp fits the isolation point and has enough lock holes for every worker involved
Valve lockouts	Preventing valve movement	Use on ball valves, gate valves, butterfly valves, and other fluid, gas, steam, or chemical lines	Match the device to the valve type, handle size, pipe layout, and open/closed position
Breaker lockouts	Preventing electrical circuits from being switched on	Use on panel breakers, machine circuits, and electrical isolation points	Match the lockout to the breaker style, voltage environment, and panel clearance
Plug lockouts	Blocking access to an electrical plug	Use for cord-connected equipment that can be isolated by unplugging	Select a size that fully encloses the plug and prevents it from being reconnected
Cable lockouts	Securing multiple or irregular energy-isolating points	Use on oversized valves, linked handles, disconnects, or equipment with several lockout points	Check cable length, cable diameter, coating, body material, and whether the cable can be pulled tight
Group lock boxes	Controlling keys during group lockout	Use when multiple employees service one machine or when multiple machines are locked out together	Choose based on number of workers, number of keys, portability, and whether wall-mounted or portable control is needed
Lockout tags	Communicating lockout status and authorized employee information	Use with locks and devices to warn that equipment must not be operated	Tags should resist moisture, oil, dirt, and tearing, and must clearly identify the person responsible for the lockout

A complete LOTO equipment list usually includes more than one device type because most machines have more than one hazardous energy source. For example, a packaging machine may need a breaker lockout for electrical energy, a valve lockout for compressed air, a cable lockout for linked access points, and individual padlocks for each authorized employee. The safest selection process starts with the energy control procedure, not the product catalog.

Types of Lockout Tagout Devices

The main types of lockout tagout devices include lockout padlocks, lockout hasps, valve lockouts, circuit breaker lockouts, plug lockouts, cable lockouts, group lock boxes, and lockout tags. Each device controls a different part of the energy isolation process, so the best choice depends on the equipment design, energy source, and number of authorized employees involved.

Lockout Locks

Lockout locks are specialized padlocks to secure energy-isolating devices and prevent accidental re-energization of machinery. For example, in the image, a lockout device, such as a circuit breaker lockout, is placed over the energy control mechanism to keep it in the "OFF" or "safe" position. The lockout lock is then attached through the lockout device, ensuring the energy source cannot be turned back on without removing the lock.

All lockout tagout padlocks must have a label indicating “LOCKED OUT” or “DANGER” to instantly notify any individual in the vicinity that the equipment is currently undergoing maintenance and should not be operated. The types of lockout tagout padlocks are available in varying keying systems, body and shackle materials, and shackle lengths.

When choosing LOTO locks, pay close attention to the keying system. Keyed-different padlocks are commonly used for personal lockout because each employee controls only their own key. Keyed-alike locks may be used for controlled equipment sets, but they require strict management to prevent unauthorized removal. Master-keyed systems can simplify supervision, but they should be limited to written procedures because uncontrolled master key access can weaken the purpose of personal lockout.

LOTO Tags

Once a lockout lock is secured to an energy-isolating device, a LOTO tag is attached to the lock or nearby lockout device. While it does not physically prevent re-energization like a lock, it indicates the machine or equipment is locked out and must not be operated.

The lockout tagout tag, like the one shown above, states messages such as "Do Not Operate," "Danger – Equipment Locked Out," or "Authorized Personnel Only", preventing accidental or unauthorized removal. It also includes critical information about who applied the lock, why the equipment was locked out, and when it was locked out. LOTO tags stay in place until the authorized employee removes their lock, and the machine is safe to restart.

Tags are not a substitute for locks when the equipment can be physically locked out. OSHA allows tagout-only systems only when a lockout device cannot be applied and the employer provides equivalent protection through additional measures. In normal lockout tagout practice, tags should be treated as communication tools, while locks and lockout devices provide the physical control.

Lockout Hasps

Lockout hasps allow multiple workers to secure an energy control point during maintenance or servicing. After shutting down the machine and isolating the energy source, the hasp is placed through the control switch, electrical plug lockout, or breaker switch to physically prevent reactivation. Each worker then places their individual lockout lock through one of the available holes in the hasp.

The image above shows the lockout device remains locked out since there are still locks in place; this ensures that no one can restore power until every worker has removed their own lock. Typically, this group lockout device can accommodate up to six lockout locks.

Use a lockout hasp when one isolation point affects more than one authorized employee. The hasp keeps the energy-isolating device secured until every worker removes their individual lock. This matters during shift changes, contractor work, and maintenance tasks where mechanics, electricians, and operators may be exposed to the same hazardous energy source.

Clamp-on Breaker Locks

Clamp-on breaker locks are lockout tagout devices designed to physically prevent the circuit breaker switch from being turned on. They are engineered to be compatible with a variety of circuit breakers, including miniature circuit breakers (MCBs) and larger industrial breakers for high-voltage systems.

A breaker lock may be clamped, snapped, or slid onto the breaker switch, and then a lockout padlock is inserted through the breaker lock to ensure that only authorized employees can remove it. Breaker locks are critical for electrical safety, helping protect workers from electric shock, arc flash, and other hazards associated with live circuits.

Adjustable Cable Lockouts

Adjustable cable lockout devices are used to lock out multiple energy sources, irregularly shaped equipment, or difficult-to-reach energy sources. They are often used on large valve handles, multiple disconnects, linked handles, or equipment with several lockout points that must remain secured together. The cable should be routed so it cannot slip off, loosen, or allow partial movement of the control point.

A cable lockout is typically made of multi-stranded steel cables, as shown in the image, insulated with a UV-protected PVC coating, and housed in a non-conductive, high-impact body. While the cable lockout secures multiple energy isolation points, it alone does not physically prevent removal unless a LOTO lock and tag are properly attached.

Group Lockout Box

A group lockout box serves as a centralized locking system, ensuring that no single worker is put at risk by premature startup during group lockout operations. When several workers are servicing a single piece of equipment, the group lockout box secures the key to the energy isolation lock, and each worker applies their personal lock to the box. After completing their servicing or maintenance task, each worker removes their personal lock from the box. Only when all workers have removed their locks can the authorized person retrieve the key from the box and safely restore power.

Similarly, when multiple workers are servicing multiple pieces of equipment, a group lockout box simplifies energy control by securing all keys for the locked-out machines in one central location. Workers place their locks on the box, ensuring that no machine can be restarted until everyone has completed their work.

Valve Lockouts

A valve lockout secures the valve in the closed or off position, preventing the unintended release of hazardous energy such as pressurized gases, liquids, steam, or chemicals during maintenance or servicing. Different valve types require specific lockout devices: gate valves need valve lock covers, ball valves require clamp-on devices, and butterfly valves use lever-blocking lockouts. Using the wrong device can lead to improper fit, accidental energy release, compliance violations, and serious workplace hazards.

Plug Lockouts

Electrical plug lockout devices function by physically blocking the plug of an electrical cord from being inserted into an outlet. The device is typically constructed with a durable, tamper-resistant enclosure that surrounds the plug, as seen in the image above. The enclosure is then secured with a lockout lock and tag, ensuring that the plug cannot be removed or accessed without the proper authorization. Plug lockouts come in different sizes, and using one that’s too large or too small may make the lockout tagout procedure ineffective.

Push Button Lockout

A push button lockout is designed to prevent accidental activation of critical control buttons. These buttons, often responsible for starting, stopping, or triggering emergency shutdowns on machinery and equipment, can pose significant hazards if operated inadvertently during maintenance, repair, or servicing tasks.

Similar to the image above, the lockout device itself is typically a sturdy, purpose-built cover that fits snugly over the push button or switch. It's often secured in place using strong, double-sided adhesive tape, creating a physical barrier that prevents the button from being pressed. To ensure that the control remains isolated, a lockout tagout padlock and tag are then attached to the device.

Other Specialized Lockout Devices

In addition to commonly used devices, there are specialized LOTO devices designed for specific applications. Below are some of these specialized lockout tagout devices:

- Confined Space Cover: Used to secure confined spaces, such as tanks, ducts, or manholes, by preventing unauthorized entry during maintenance or cleaning.
- Spigot Lockout: Designed to lock out water or fluid spigots, preventing unauthorized access to water supply systems.
- Lockout Tagout Kits : These are comprehensive kits that contain multiple LOTO devices, including padlocks, tags, hasps, circuit breaker locks, valve locks, and other accessories, ensuring that workers have all the necessary tools for LOTO procedures.
- Lockout Tagout Bag : A portable pouch designed to store essential LOTO devices, allowing maintenance teams to carry tools to different locations within a facility.
- Cinch Bag: Used for isolating irregularly shaped energy sources, multiple lockout points, or when a flexible and enclosed locking mechanism is required.
- Lockout Tagout Station: Used as a centralized storage unit designed to keep all essential LOTO devices, which helps ensure workers can quickly find and use the necessary lockout equipment when needed.

More lockout tagout devices come in a wide variety of sizes and styles. Some companies even order custom-built devices to ensure the perfect fit for their needs and situations. The most important thing is to get the appropriate lockout tagout device that can prevent power flow so the equipment stays de-energized throughout the maintenance and repair processes.

Integration of Advanced Technologies on Lockout Devices

The integration of advanced technologies into lockout tagout devices has sparked several debates among industry experts, regulatory bodies, and workers. While smart LOTO systems offer benefits like real-time monitoring and automation, concerns about system failures, cybersecurity threats, and regulatory compatibility remain significant hurdles. The future of advanced LOTO integration will likely depend on developing clearer safety standards, improving technology reliability, and addressing cybersecurity risks while ensuring workers remain protected.

Types of Lockout Tagout Devices FAQs

What is a lockout device?

A lockout device is a physical mechanism used to isolate energy sources by preventing the operation of machinery or equipment during maintenance or servicing. It typically involves padlocks, valve locks, circuit breaker locks, or other specialized devices to ensure worker safety.

What is a tagout device?

A tagout device is a warning label or tag attached to an energy-isolating device to inform workers that the equipment is locked out and should not be operated. It is used when a lockout device is not feasible and serves as a visual deterrent to prevent accidental energization.

Which are the 4 types of LOTO devices?

The four common types of LOTO devices include padlocks, hasps, valve lockouts, and circuit breaker lockouts, each designed for specific types of energy isolation.

What are the different types of LOTO locks?

The main types of LOTO locks include keyed-different padlocks, keyed-alike padlocks, master-keyed padlocks, and color-coded lockout padlocks. Keyed-different locks are commonly used for personal lockout because each authorized employee controls their own key. Color-coded locks help identify departments, roles, or equipment groups, but the color system should be standardized across the facility to prevent confusion.

What should be included in a LOTO equipment list?

A LOTO equipment list should include lockout padlocks, lockout tags, lockout hasps, valve lockouts, circuit breaker lockouts, plug lockouts, cable lockouts, group lock boxes, and any machine-specific lockout devices required by the facility’s energy control procedures. The list should be based on actual energy sources and isolation points, not a generic kit.

What color is the group isolation tag?

The group isolation tag is typically orange, distinguishing it from personal or equipment-specific lockout tags. This signifies a warning that a group of equipment has been isolated and is ready for maintenance or repair.

Why are LOTO locks different colors?

LOTO locks come in different colors to indicate ownership, roles, or departments, helping to prevent confusion and ensure proper identification during lockout procedures.