Indium tin oxide (ITO) or tin-doped indium oxide is a mixture of indium oxide and tin oxide, in which the tin component can contribute up to one-fifth of the material composition. Indium tin oxide is a transparent (see-through) material with electrical conductivity. Indium tin oxide is applied mainly as a film to create transparent conductive coatings in the opto-electronic industry, for example to protect image sensors of digital cameras, as a conductive catalyst carrier, or displays based on LED technology (LED = light emitting diode). It is used in heated defrosting coatings for the cockpit windows of the Airbus. Another interesting new application is the usage of indium tin oxide in a new generation of solar cells.
How can I come into contact with this material?
The most likely route for indium tin oxide nanoparticles to enter the human body is via inhalation (breathing in) of the raw material during processing. Other uptake routes like accidental swallowing of ITO nanoparticles are extremely unlikely. Eye contact should be avoided.
Is there any risk from this material to humans and the environment?
Irritation of the nose, throat and eyes are symptoms that can occur in humans upon exposure to high concentrations of ITO nanoparticles. Thus, air-borne exposure to indium tin oxide dust, e.g. during the production of displays, should be avoided. Indium tin oxide particles of 950 nm in size have been shown to cause lung damage in hamsters and this was linked to its accumulation in lung tissues. There is some evidence that indium tin oxide appears to dissolve in the body and forms soluble indium. Another study has shown a negative effect of indium tin oxide (ITO) on the reproductive capacity in animals.
Conclusion
For the consumer the chances of being exposed to indium tin oxide (ITO) are very small. However at the workplace (e.g. in in the solar cell industry) it is important to take the necessary safety precautions to avoid inhalation when handling this material.