Oxygen Toxicity
Definition
Oxygen toxicity is a condition caused by breathing oxygen at elevated partial pressures, potentially leading to seizures and other symptoms.
More on Oxygen Toxicity
Oxygen toxicity can affect the central nervous system (CNS) when partial pressure of oxygen (PPO₂) exceeds safe limits, typically above 1.4 ATA for recreational dives. Symptoms may include visual disturbances, nausea, twitching, and convulsions without warning. It’s a primary concern in technical and Nitrox diving. Dive computers and Nitrox training teach divers to plan dives that stay within safe exposure levels. Oxygen toxicity can be fatal if a seizure occurs underwater, so planning and awareness are essential.
Frequently Asked Questions
Breathing oxygen at high partial pressures, especially beyond 1.4–1.6 ATA, can overstimulate the nervous system and cause seizures.
Analyze your gas, set your computer correctly, and never exceed the maximum operating depth (MOD) for the blend.
For EAN32, the MOD at a PPO₂ of 1.4 is about 33 meters (110 feet). Exceeding this increases oxygen toxicity risk.
Rarely, unless diving with enriched air and exceeding depth limits. Recreational air diving usually stays within safe PPO₂ limits.
Twitching, dizziness, vision changes, nausea, anxiety, and seizures. Symptoms may appear suddenly and without warning.