When Hazardous Energy Is Not Controlled: The Reality Behind Oilfield Startup Injuries Key Takeaways: A lockout/tagout violation occurs when an employer fails to de-energize, isolate, lock, and tag equipment before servicing it, allowing stored or live energy to release without warning and cause crush injuries, amputations, electrocution, or death. Federal standard 29 C.F.R. § 1910.147…