Safety Best Practice
LOTO vs LOTOTO: understanding the difference and when to apply each
A practical comparison of Lockout/Tagout and Lockout/Tagout/Try-out procedures with guidance on regulatory requirements across jurisdictions.
The core difference
LOTO focuses on locking and tagging hazardous energy sources so equipment cannot be started or energized unexpectedly. LOTOTO adds a deliberate try-out step: the team verifies that the isolation actually worked before work begins.
For high-energy industrial work, LOTOTO is usually the stronger operational habit because it confirms the zero-energy state instead of assuming it from the lock and tag alone.
What the system should capture
A robust permit-to-work workflow should record the isolation points, lock numbers, responsible isolator, zero-energy readings, try-out result, verifier signature, time, and evidence attachments.
These records should be preserved as part of the permit history, not treated as ordinary editable checklist fields.