We often find ourselves facing hazards that the customer didn't expect or didn't want to hear about. Our role is to dig into the details, report on the findings, and ensure workers are safer.

One of the common issues we encounter involves a worker using a makeshift solution, rubber band, tie-wrap, etc., to hold down a 3-position enabling device. While the device itself is small, defeating it represents a failure of the safety requirements for hazardous operations.

 

The Problem: Undermining Continuous Control

This simple act constitutes defeat or circumvention of a safety function, which is a key consideration when evaluating risks.

  1. The Designed Safety Function: The enabling device is manually operated and, when held in its midpoint (Position 2: ENABLED), grants the operator exclusive, but momentary, control over the machine, often during setup or programming. This device is mandated to have three positions, ensuring that releasing the button (Position 1: OFF) or pressing it too hard (Position 3: OFF) both immediately initiate a stop command. This requires continuous, deliberate physical control by the worker
  2. The Defeat: By using a simple aid like a rubber band, the worker attempts to hold the button permanently in the ENABLED position. This action simulates continuous actuation without requiring the worker's presence or conscious control. Standards require that enabling devices be selected and arranged to minimize the possibility of defeat. Using a simple aid, such as tape, a cord, or a rubber band, is recognized as a means of circumventing protection that must be addressed.
  3. The High-Risk Consequence: Tying down the button negates the critical immediate stop command that should trigger if the operator releases the device or compresses it in a panic. The worker is exposed to a significantly increased risk as the primary protective function intended to prevent hazardous motion is rendered ineffective. This act is analogous to installing a short circuit on a door switch.

 

The Solution: Education and Addressing Misuse

When we point this out during a review, it falls under the category of unauthorized changes or reasonably foreseeable misuse. The motivation is often borne out of inconvenience or poor ergonomics, but the result is a significant increase in hazard.

 

Our Team Views This As An Opportunity To Educate:

  • To explain precisely how the device must be maintained (Position 2) and why the failure modes (Position 1 and 3) must be preserved.
  • Emphasizing the need for administrative controls.

Safe Work Procedures and Training must be developed to prevent unauthorized changes and ensure personnel understand that they must not intentionally circumvent protective measures. By addressing such a lapse in safety, what seems like a problem can be converted into an opportunity to enhance workplace safety.