Which is one of the two greatest hazards at a confined-space incident?

One of the greatest hazards at a confined-space incident is the lack of oxygen. In confined spaces, the atmosphere can become depleted of oxygen due to various factors such as confined air volume, consumption by workers, or chemical reactions. A safe working environment typically requires an oxygen level of at least 19.5%. When oxygen levels drop below this threshold, workers can quickly lose consciousness or even suffer from asphyxiation, leading to severe injury or death if not addressed promptly.

Understanding this critical hazard is essential for developing proper safety protocols and training for emergency responders, as it emphasizes the need for continuous atmospheric monitoring and the implementation of appropriate ventilation techniques when entering confined spaces.