One of the hazards of occupational diving is pulmonary oxygen toxicity, which can lead to reduced lung diffusion capacity and fibrosis. The current gold standard to determine the ‘safe limits’ for oxygen was developed more than 50 years ago and lacks the accuracy required for occupational specialists. These restrictions may be overcome by new diagnostic methods like exhaled breath analysis, which would allow occupational specialists to accurately monitor pulmonary health in the individual diver, and thus reduce long-term health effects of professional diving.