In most cases, we advise companies to perform an equipment and machine risk assessment before accidents happen to avoid injuries, along with complications and fines assessed by OSHA. In this case, the accident already happened, and we were tasked with eliminating the dangerous conditions that contributed to the incident.
To provide safe access to the area containing the finished rolls, we created a muting zone utilizing an area scanner and light curtain. The primary safety device is the light curtain, which would trigger an emergency stop if breached. If an operator needed to access the zone, then they would press a Request Access push-button. Once the PLC confirmed all hazardous equipment was in a safe state, the operator would receive notification that the area was now safe to enter. Once the operator is finished with their task, they leave the area and press Request Secure. The area scanner will perform a brief check to verify that the hazardous area is clear, the light curtain will reactivate, and machine movement will be re-enabled.
OSHA Standard Number 29 CFR 1910 covers the safety requirements of this situation, and because the activities taking place were during normal production operations and “routine, repetitive, and integral to the use of the equipment,” we were able to bypass the LOTO requirement and implement the muting zone solution. It takes a significant amount of time to properly follow LOTO procedures while our streamlined solution only requires pressing a push-button before starting the task and a push-button after the task is complete. In that regard, this solution contributed to an increase in production volume.