Scuba Diving International (SDI) Computer Nitrox Practice Exam

What is the primary risk associated with Nitrox diving?

1. Barotrauma

2. Decompression sickness

3. Oxygen poisoning

4. Air embolism

The correct answer is: Oxygen poisoning

The primary risk associated with Nitrox diving is oxygen poisoning, also known as oxygen toxicity. This condition occurs when a diver is exposed to an elevated partial pressure of oxygen, which can happen when using Nitrox blends with higher concentrations of oxygen than regular air (21% oxygen). When divers breathe oxygen at pressures greater than 1.4 ATA (atmospheres absolute), it can lead to central nervous system toxicity, causing symptoms such as visual or auditory disturbances, convulsions, and loss of consciousness. It is essential for divers using Nitrox to monitor their oxygen exposure and keep their depth within the limits specified for the gas mixture they are using, preventing oxygen toxicity. While other risks, such as barotrauma, decompression sickness, and air embolism, are significant in diving, they are more commonly associated with the use of regular air and do not specifically relate to the unique aspects of Nitrox diving. Oxygen poisoning is the hallmark concern for those using Nitrox due to the increased risks introduced by higher oxygen levels in the breathing gas. Understanding and managing this risk is vital for safe Nitrox diving practices.