Excavations should be tested for oxygen deficiencies if the levels drop below?

Oxygen deficiency in excavation sites poses serious safety risks, and it is crucial to monitor atmospheric conditions in these environments. The universally accepted standard for healthy oxygen levels in the atmosphere is approximately 20.9%. When oxygen levels drop below 19.5%, they are considered deficient, leading to potential health hazards for workers. At this level, the risk of impaired physical and cognitive functions increases significantly, making it essential to test for and address deficiencies to ensure worker safety.

Lower thresholds, such as 18.5%, 20.5%, or 21.5%, do not accurately represent the critical threshold for oxygen deficiency identified by safety guidelines. Therefore, recognizing 19.5% as the minimum safe level is essential for maintaining a safe working environment in excavation situations.