What must the atmosphere be evaluated for in confined spaces?

Evaluating the atmosphere in confined spaces is critical for ensuring the safety of personnel entering the area. Oxygen levels are specifically monitored because they are vital for human survival. In most confined spaces, the atmosphere can become deficient in oxygen, leading to asphyxiation or unconsciousness. The acceptable level of oxygen is typically between 19.5% to 23.5%. If the oxygen concentration falls below 19.5%, individuals entering that space risk severe health consequences.

While factors such as temperature, humidity, and airflow can impact working conditions and overall safety, they do not pose immediate life-threatening risks like oxygen levels do. Consequently, the primary focus during atmospheric evaluations in confined spaces is on the oxygen content, making it the most critical factor to assess before proceeding.