Which precaution is essential before entering a confined space?

Performing an atmospheric test is essential before entering a confined space because it is crucial for ensuring the safety of workers. Confined spaces can have hazardous atmospheric conditions, such as low oxygen levels, toxic gases, or flammable vapors. Without testing the atmosphere, workers would be unaware of these dangers, which could lead to serious injuries or fatalities.

Atmospheric testing typically involves using calibrated monitoring devices to measure levels of oxygen, flammable gases, and toxic substances. This procedure helps to identify whether the environment is safe for entry and whether additional safety measures, such as ventilation, are required.

While other precautions like checking with a supervisor, wearing personal protective equipment, and obtaining a work permit are important components of a comprehensive safety plan, they do not address the immediate risk posed by the atmospheric conditions specific to confined spaces. Only by performing an atmospheric test can one ensure that the airborne hazards are assessed and appropriately managed before entering.