Strictly adhere to the LOTO (Lockout-Tagout) system for locking and tagging.
Lockout/Tagout (LOTO) is a core safety system in industrial production, equipment maintenance, and maintenance operations for controlling hazardous energy and preventing accidental equipment startup. It is the last line of defense for protecting the lives of workers. Its core principle is to completely cut off all types of hazardous energy sources of equipment through standardized processes such as physical isolation, exclusive locking, tagging warnings, and energy verification, and to prevent safety accidents caused by residual energy, improper operation, and accidental startup.
In actual production operations, most mechanical injuries, electric shocks, asphyxiation, compression, hydraulic falls, etc., result from the fortunately psychology of workers, simplified procedures,and inadequate implementation of the system. There are typical violations such as not locking,only tagging without locking,not releasing residual energy, and violating regulations when multiple people are working. This article summarizes typical LOTO accident cases in seven industries:mechanical manufacturing,chemical vessels,power,food processing,environmental water treatment,mining metallurgy,and construction engineering. It deeply analyzes the root causes of the accidents,summarizes safety warnings,and provides references for safety production and on-site operation control in various industries.
1. Mechanical Manufacturing Industry:Ignoring physical isolation,accidental startup leads to fatal crush accidents
Case 1: Death accident caused by lack of LOTO isolation during grinding machine debugging
A mechanical equipment engineer at an automotive parts manufacturing enterprise was debugging a precision grinding machine when he found that the processing accuracy was out of specification. He did not follow the safety procedures to stop the machine,lock it, and tag it for warning,but only informed the operator to suspend work verbally and directly entered the dangerous area of the equipment for debugging. During the operation,the safety interlock device of the equipment failed,and the operator,unaware,touched the control button,causing the equipment to suddenly start and crush the engineer between the equipment work positions,resulting in immediate death.
The core reason of the accident: The workers had a weak safety awareness,completely skipping the LOTO energy isolation process,treating verbal suspension as safety isolation; they did not conduct hazard inspections on the failed safety interlock devices,did not lock the equipment switch with physical locks,and did not have warning signs to remind the on-site personnel,and violated the regulations by entering high-risk operation areas.
Case 2: Accidental start-up injury during crusher maintenance
A maintenance worker at a processing plant was dealing with a blockage fault of the crusher when he only switched the equipment to the pause state,did not cut off the main power supply,and did not lock and tag it. During the maintenance process, the maintenance worker accidentally touched the equipment remote control button he carried with him and started the crusher. The crusher immediately started and rolled the maintenance worker into the equipment,causing irreversible injuries.
The core warning of the accident: “Pause standby” is definitely not the same as “zero energy state of safety”,all equipment maintenance,fault cleaning,and debugging operations must completely cut off the energy source,follow the LOTO locking and tagging process, and avoid taking the risk of violating the rules operations.
Post time: Jun-02-2026

