Safety Incident Sounds the Alarm — The Time for LOTO Upgrades Is Now!

In early February 2023, a safety incident occurred at the Shanghai factory of a globally renowned electric vehicle manufacturer, resulting in the death of a 31-year-old male employee and a direct economic loss of 2.7 million RNB.

The investigation confirmed that the accident was caused by one employee entering a workstation without following the company’s prescribed Lockout-Tagout (LOTO) procedure, and another employee restarting the equipment without first checking whether anyone was inside the automated workstation. This led to the tragedy—yet another bloody lesson.

It was another typical case of “a person still inside the danger zone, but the equipment gets started.” Although the company had strict LOTO regulations, if the process had been followed rigorously, the tragedy would not have happened. However, relying on employees’ self-discipline to implement risk control measures is, in itself, a flaw.

LOTO — Tag for Safety, Lock for Life

LOTO stands for Lockout-Tagout, a method compliant with OSHA standards that involves isolating and locking certain hazardous energy sources to prevent personal injury. It is mainly applied to situations such as locking and tagging the main power switch when cutting off a machine’s power supply, or locking and tagging when safety doors are unlocked and opened. Generally, there is no restriction on the number of people entering or exiting the robot’s workspace, making it suitable for large-scale equipment applications.

Limitations of Existing LOTO Solutions

Current LOTO solutions have their advantages, but also some “hard flaws.” For example, the locks are usually heavy and inconvenient for on-site personnel to carry. Additionally, workers must enter and exit through the same door, which can reduce work efficiency if the protected area is large. In real-world use, it is common for staff to bypass procedures, potentially leading to accidents.

Looking ahead, mechanical lockout and tagging operations cannot be linked to safety door authorization for locking/unlocking. They also lack back-end data tracking, making it impossible to record each worker’s lockout/tagout actions — a clear mismatch with the manufacturing industry’s development trends.

The New LOTO Solution — Using the Latest RFID-Based Electronic Access Authorization System

Pilz has introduced the Key in Pocket solution, which can be considered a replacement technology for traditional lockout/tagout.

Essentially, Key in Pocket provides purely electronic restart protection. It consists of a PNOZmulti or PSS 4000 safety controller combined with a PITreader unit, enabling sign-in/sign-out management. This system effectively prevents unauthorized equipment restarts and protects personnel working inside hazardous areas.

Compared with traditional LOTO solutions, Key in Pocket offers major advantages:

The technology integrates a blind-spot check function, which is highly practical. When there is only one key remaining signed in on the safety list (meaning there should be only one person in the danger zone), the blind-spot check is automatically activated (via an indicator light or buzzer).

The holder of that last key must reach the machine’s blind-spot location within a set time to check whether any other personnel remain in the danger zone. After completing the check, they press the Blind-Spot Check Confirmation Button to turn off the indicator/buzzer. Only then can the last keyholder sign out via the PITreader at the safety door.

When all safety doors are locked, the machine can then be restarted.

If you want, I can also adapt this translation into a professional safety industry article style so it reads more like a published case study. That would make it more persuasive for industrial safety audiences.