What Is Lockout/Tagout?
Lockout/Tagout (LOTO) is a safety procedure that ensures dangerous machines and energy sources are properly shut off and not started up again before maintenance or repair work is completed. It requires:
- Disconnecting and isolating the machine from its energy source(s)
- Applying a lock and tag to the energy-isolating device
- Verifying the machine can't be operated until the lock is removed
When LOTO Is Required
LOTO is required whenever a worker must:
- Remove or bypass a guard or safety device
- Place any part of their body in the danger zone of a machine
- Service or maintain equipment where unexpected startup could cause injury
- Work on or near exposed electrical circuits
- Repair plumbing or compressed air systems under pressure
- Work on hydraulic or pneumatic equipment
Types of Hazardous Energy
Electrical Energy
- Most common form in construction
- Present in power tools, equipment, lighting, panels
- Can cause shocks, burns, or electrocution
Mechanical Energy
- Stored in moving parts that continue to move after power is off
- Examples: flywheels, springs, elevated components
- Can cause crushing injuries or amputations
Hydraulic/Pneumatic Energy
- Pressurized liquids or air
- Found in hydraulic lifts, nail guns, jackhammers
- Can cause injection injuries or struck-by incidents
Chemical Energy
- Pressurized or flowing chemicals
- Potential for burns, explosions, or toxic exposure
- Common in some specialized construction
Thermal Energy
- Hot surfaces, steam, molten materials
- Can cause severe burns
- Found in roofing work, asphalt operations
Gravity
- Elevated components that could fall
- Vehicles or equipment that could roll
- Common cause of caught-between injuries
Basic LOTO Procedure
1. Preparation
- Identify all energy sources
- Determine shutdown procedure
- Gather proper locks and tags
- Inform affected workers
2. Shutdown
- Turn off equipment using normal controls
- Make sure all moving parts have stopped
- Follow established sequence for complex equipment
3. Isolation
- Disconnect or isolate equipment from ALL energy sources
- Close valves, throw switches, disconnect plugs
- Install blocks or other mechanical restraints if needed
4. Lockout and Tagout
- Apply YOUR personal lock to isolation devices
- Each worker applies their own lock
- Attach a tag with your name, date, and reason for lockout
5. Verify De-energization
- Try to start equipment using normal controls
- Test with meters to ensure electrical circuits are de-energized
- Check pressure gauges for hydraulic/pneumatic systems
- Return controls to "off" position after testing
6. Perform the Work
- Complete the maintenance or repair
- Keep lockout devices in place the entire time
7. Restore to Service
- Ensure all tools and items are removed
- Verify controls are in neutral/off position
- Check that all workers are clear of equipment
- Remove YOUR lock and tag (only the person who applied it)
- Re-energize the equipment
- Notify affected employees
Special Situations
Group Lockout
When multiple workers are involved:
- Each worker applies their own lock to a group lockout box or hasp
- A qualified person controls the keys to the energy isolation points
- No one removes their lock until their work is complete
- The last lock removed signals the equipment can be restarted
Shift Changes
When work continues across shifts:
- Outgoing workers don't remove locks until incoming workers apply theirs
- Use a shift transfer lock or special procedure
- Document the change in responsibility
- Never leave equipment unattended without locks
Contractor Coordination
When contractors are involved:
- Host employer communicates LOTO procedures
- Contractors follow host procedures or coordinate their own
- Both parties inform each other about their LOTO activities
- Coordinate when responsibilities overlap
LOTO Equipment
Locks
- Uniquely keyed (only one key per lock)
- Substantial and durable
- Standardized by color, shape, or size
- Identified to a specific worker
- Used ONLY for lockout purposes
Tags
- Clearly state "Do Not Operate" or similar warning
- Include worker's name and contact information
- Show date of application
- Explain reason for lockout
- Weather resistant and durable
Energy Isolating Devices
- Disconnect switches
- Circuit breakers
- Valve lockouts
- Pneumatic lockouts
- Hydraulic lockouts
- Plug covers and lockouts
Common LOTO Mistakes
- Using the wrong type of lockout device
- Failing to identify all energy sources
- Not verifying zero energy state
- Removing someone else's lock
- Using locks for purposes other than LOTO
- Leaving keys accessible to others
- Not following established procedures
- Rushing through the process
Your Rights and Responsibilities
As a Worker
- Right to have proper LOTO training
- Right to have appropriate LOTO devices
- Responsibility to follow established procedures
- Never remove another worker's lock
- Report any LOTO violations immediately
As a Supervisor
- Ensure workers are trained in LOTO
- Provide proper LOTO equipment
- Enforce LOTO procedures
- Verify compliance through inspections
- Address violations promptly