This record contains information for iridium in its zero valence state only. For general toxicity and environmental fate of iridium ions and iridium compounds, refer to the IRIDIUM COMPOUNDS record; for compound specific information, refer to the appropriate individual records, e.g., iridium tetrachloride. For information on the radiological aspects of iridium and its compounds, refer to the IRIDIUM, RADIOACTIVE record For general toxicological, safety and handling, and environmental information on ionizing radiation emitted from chemical sources including iridium, refer to the IONIZING RADIATION RECORD.