What is Oxygen Toxicity in Scuba Diving?

Oxygen Toxicity Causes Convusions and Drowning -- But It's Avoidable

Male Scuba Divers, Oxygen Toxicity, Enriched Air Nitrox
Scuba Divers who use nitrox should know about the dangers of oxygen toxicity. Getty Images

Oxygen toxicity is a medical condition caused by exposure to oxygen at high pressure. Oxygen toxicity is a concern for scuba divers who dive beyond recreational depth limits, use gas blends such as enriched air nitrox, or use 100% oxygen as a decompression gas. There are two main types of oxygen toxicity: central nervous system (CNS) oxygen toxicity and pulmonary oxygen toxicity.

CNS oxygen toxicity is caused by exposure to oxygen partial pressures greater than 1.6 ATA. It can result in convulsions, pulmonary barotrauma, and death.

Pulmonary oxygen toxicity is caused by exposure to elevated partial pressures of oxygen for long periods of time ​and is primarily a concern for technical divers who decompress on oxygen. Pulmonary oxygen toxicity causes a burning sensation in the trachea, coughing, shortness of breath, and eventually lung failure. ​Learn more about oxygen toxicity.