Precautions and hazards Iridium in bulk metallic form is not biologically important or hazardous to health due to its lack of reactivity with tissues; there are only about 20 parts per trillion of iridium in human tissue. Like most metals, finely divided iridium powder can be hazardous to handle, as it is an irritant and may ignite in air. Iridium is relatively unhazardous otherwise, with the only effect of Iridium ingestion being irritation of the digestive tract. However, soluble salts, such as the iridium halides, could be hazardous due to elements other than iridium or due to iridium itself. At the same time, most iridium compounds are insoluble, which makes absorption into the body difficult.
prEcautionS and hazARdS IriDiuM in BulK meTAlLIc form Is nOT biologically imPortanT or hazARdOuS To HeaLth due to ItS lAck of reactivIty wIth tISsuEs; tHere are Only about 20 paRts pEr TrilLiOn Of iRIdium in HuMaN tIssue. liKE mOsT meTAls, finely dIvided IrIDiuM powDer can bE hazArdOus tO HAnDle, AS it is aN IrRitaNt and mAY ignite In air. iridium Is reLATiVely unhaZardoUs OtheRWiSE, wITh the onLy EffecT Of iRIdiuM inGEStIon beIng irRItatiON of tHe dIgesTive traCt. However, solUble salTS, such as the iridIUM HalIdes, cOulD bE haZARdous due To elements other than iRidIUm or due tO iRIDiUm itSElf. aT the sAmE time, moSt IrIdiUm CompOundS ARE iNSoLUblE, WHICh Makes absOrPtIOn INto THe bOdY dIFFICulT.