Enriched Air Nitrox Level 2 Practice Test 2026 – Complete Exam Prep

Diving with higher oxygen concentrations in nitrox significantly increases the risk of central nervous system (CNS) toxicity. This condition occurs when the partial pressure of oxygen in the breathing mixture exceeds safe levels, typically above 1.4 atmospheres for recreational diving. CNS toxicity can lead to symptoms such as visual disturbances, muscle twitching, and in severe cases, seizures, which can be dangerous underwater.

Understanding the implications of using nitrox with higher oxygen concentrations is crucial for divers. While nitrox can enhance bottom time and reduce nitrogen absorption, careful management of the partial pressure of oxygen is essential to ensure safety. Divers need to be aware of their depth and the percentage of oxygen in the mix to avoid exceeding the limits that could trigger CNS toxicity.

The other options refer to various risks associated with diving, but they do not accurately relate to the specific effects of elevated oxygen concentrations in nitrox. For example, overheating is generally not a direct effect of oxygen levels, equipment failure is more related to mechanical issues rather than gas composition, and buoyancy control difficulties can stem from other factors like gear and personal buoyancy management rather than the oxygen level in the gas mix.