Advance Access publication January 28, 2009 Sintered Indium-Tin-Oxide (ITO) Particles: A New Pneumotoxic Entity

Indium-Tin-Oxide (ITO) is a sintered mixture of indium-(In2O3) and tin-oxide (SnO2) in a ratio of 90:10 (wt:wt) that is used for the manufacture of LCD screens and related high technology applications. Interstitial pulmonary diseases have recently been reported in workers from ITO producing plants. The present study was conducted to identify experimentally the exact chemical component responsible for this toxicity and to address possible mechanisms of action. The reactivity of respirable ITO particles was compared with that of its single components alone or their unsintered 90:10 mixture (MIX) both in vivo and in vitro. For all endpoints considered, ITO particles behaved as a specific toxic entity. In vivo, after a single pharyngeal administration (2–20 mg per rat), ITO particles induced a strong inflammatory reaction. At day 3, the inflammatory reaction (cell accumulation, LDH and protein in bronchoalveolar lavage fluid