{
  "spore": "profile",
  "id": "tin-oxide",
  "spore_version": "0.2",
  "family": "oxide-ceramics",
  "name": "Tin(IV) oxide and indium tin oxide",
  "abbreviation": "SnO2, ITO",
  "role": "transparent conductor and gas-sensing oxide",
  "category": "ceramics",
  "type": "oxides",
  "summary": "Tin(IV) oxide (SnO2) is a white, water-insoluble oxide with a bulk band gap of 3.6 eV. Its safety data sheet gives a density of 6.95 g/mL and a melting point of 1630 degC. Indium tin oxide (ITO) is mostly indium oxide with 10 wt% SnO2 in the standard sputtering target, and it is used as a transparent conductive film. On the MISSE-9 flight, ITO on Kapton kept usable sheet resistance after about 0.77 years in low Earth orbit, although the ram-facing sample's sheet resistance doubled from 5230 to 10820 Ohm/square. Its solar absorptance stayed near 0.42.\n",
  "best_for": "Transparent conductive ITO films for displays and thin-film solar cells, and SnO2 as the active layer in gas sensors",
  "weakest_at": "Indium supply for ITO: China produced 70% of world indium, and USGS reports new Chinese export restrictions on indium from February 2025",
  "identity": {
    "formula": "SnO2 (tin(IV) oxide); ITO is In2O3 with 10 wt% SnO2 in the standard 90/10 target",
    "cas": "18282-10-5",
    "designations": [],
    "source": "isoflex-sno2-sds",
    "where": "Section 3 (CAS 18282-10-5, formula SnO2, molecular weight 150.71 g/mol); composition from sputtertargets-ito, Standard Composition row"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "uv"
    ],
    "applications": [
      "electronics-and-chips",
      "thermal-control",
      "solar-arrays"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, tin(IV) oxide (SDS)",
      "value": 6.95,
      "bound": "exact",
      "unit": "g/mL",
      "scope": "material",
      "conditions": {
        "form": "tin(IV) oxide powder, CAS 18282-10-5",
        "temperature": "25 °C"
      },
      "method": "Value printed in the physical and chemical properties section of the supplier SDS",
      "status": "ground",
      "source": "isoflex-sno2-sds",
      "where": "Section 9, Density row",
      "source_detail": {
        "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5",
        "id": "Version 1.4, revision date 10/18/2024",
        "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, tin(IV) oxide (PubChem record)",
      "value": 6.95,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "tin(IV) oxide, PubChem record; no temperature printed"
      },
      "method": "Value printed in the Density entry of the PubChem chemical and physical properties",
      "status": "ground",
      "source": "pubchem-sno2",
      "where": "Chemical and Physical Properties, Density entry (reference 25)",
      "source_detail": {
        "title": "PubChem compound record, Tin(IV) oxide (CID 16747781)",
        "id": "CID 16747781; formula O2Sn",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/16747781/JSON",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NCBI)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, tin(IV) oxide",
      "value": 1630,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "tin(IV) oxide powder"
      },
      "method": "Value printed in the SDS physical and chemical properties section (printed as 1630 °C (2966 °F))",
      "status": "ground",
      "note": "The PubChem physical description prints mp 1127 °C with sublimation at 1800 to 1900 °C; the 1127 value conflicts with the SDS and PubChem melting entries and is not used.",
      "source": "isoflex-sno2-sds",
      "where": "Section 9, Melting Point row",
      "source_detail": {
        "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5",
        "id": "Version 1.4, revision date 10/18/2024",
        "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "band_gap",
      "label": "Band gap of bulk SnO2",
      "value": 3.6,
      "bound": "exact",
      "unit": "eV",
      "scope": "material",
      "conditions": {
        "basis": "expected value for bulk SnO2 from low-temperature valence-band photoemission, with the Fermi edge taken at the conduction band minimum",
        "form": "single-crystal SnO2 surfaces"
      },
      "method": "Value quoted in an open-access review of SnO2 surface science, described as close to the expected bulk value",
      "status": "ground",
      "note": "This is the expected bulk gap quoted in the review, not an optical measurement of a film. band_gap is not in the property canon.",
      "source": "batzill-sno2-review",
      "where": "Section on valence-band spectroscopy of the (110) and (101) surfaces, paragraph with the 3.6 eV value",
      "source_detail": {
        "title": "Surface Science Studies of Gas Sensing Materials: SnO2",
        "id": "Sensors 6(10), 1345-1366 (2006), PMC3909400",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC3909400/",
        "year": 2006,
        "kind": "paper",
        "license": "open access (PMC)"
      }
    },
    {
      "benchmark": "oral_ld50",
      "label": "Acute oral LD50, rat, tin(IV) oxide",
      "value": 20000,
      "bound": "lower",
      "unit": "mg/kg",
      "scope": "material",
      "conditions": {
        "species": "rat",
        "route": "oral",
        "form": "tin(IV) oxide"
      },
      "method": "Value printed in the SDS toxicological information section (printed as greater than 20,000 mg/kg)",
      "status": "ground",
      "note": "oral_ld50 is not in the property canon. The SDS gives no LD50 for the other routes.",
      "source": "isoflex-sno2-sds",
      "where": "Section 11, Acute Toxicity, Oral LD50 row",
      "source_detail": {
        "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5",
        "id": "Version 1.4, revision date 10/18/2024",
        "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "occupational_exposure_limit",
      "label": "Occupational exposure limit, time-weighted average, tin(IV) oxide",
      "value": 2,
      "bound": "exact",
      "unit": "mg/m3",
      "scope": "material",
      "conditions": {
        "basis": "time-weighted average as printed for tin(IV) oxide; the SDS adds that tin(II) oxide has its own listing as Sn",
        "agencies": "NIOSH REL, OSHA PEL and ACGIH TLV rows in the SDS"
      },
      "method": "Limit printed in the SDS exposure controls table",
      "status": "ground",
      "note": "occupational_exposure_limit is not in the property canon. The SDS does not state whether the 2 mg/m3 figure is as tin.",
      "source": "isoflex-sno2-sds",
      "where": "Section 8, exposure limits table, Tin (IV) oxide rows",
      "source_detail": {
        "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5",
        "id": "Version 1.4, revision date 10/18/2024",
        "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Target density, standard 90/10 rotary ITO target",
      "value": 7.13,
      "bound": "lower",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "composition": "90 wt% In2O3 and 10 wt% SnO2 standard target",
        "form": "rotary (tubular) sputtering target, SKU ST11192",
        "purity": "99.99% on oxide basis"
      },
      "method": "Specification value printed on a vendor product page (the page also gives relative density of 95% or more)",
      "status": "ground",
      "note": "Vendor specification for the target, not a measured density for the tested batch.",
      "source": "sputtertargets-ito",
      "where": "Complete Technical Specifications table, Density row",
      "source_detail": {
        "title": "Sputter Targets: Indium tin oxide (ITO) rotary sputtering target, standard 90/10",
        "id": "SKU ST11192 (page undated; retrieved 2026-10-26)",
        "url": "https://www.sputtertargets.net/st11192-indium-tin-oxide-ito-rotary-sputtering-target/",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier page, linked not reproduced"
      }
    },
    {
      "benchmark": "purity",
      "label": "Purity of the standard ITO target",
      "value": 99.99,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "on oxide basis",
        "composition": "90 wt% In2O3 and 10 wt% SnO2"
      },
      "method": "Specification printed on a vendor product page",
      "status": "ground",
      "source": "sputtertargets-ito",
      "where": "Complete Technical Specifications table, Purity row",
      "source_detail": {
        "title": "Sputter Targets: Indium tin oxide (ITO) rotary sputtering target, standard 90/10",
        "id": "SKU ST11192 (page undated; retrieved 2026-10-26)",
        "url": "https://www.sputtertargets.net/st11192-indium-tin-oxide-ito-rotary-sputtering-target/",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier page, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of the ITO film used in the MISSE-9 erosion calculation",
      "value": 6.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "ITO thin film about 10 nm thick on Kapton HN/Al and FEP/Ag/Inconel sheets",
        "basis": "value used for the mass-loss and erosion-yield calculation"
      },
      "method": "Value printed in the atomic-oxygen mass-loss table as the ITO density",
      "status": "ground",
      "note": "A film density used for a calculation, not measured by the authors on a bulk part.",
      "source": "nasa-misse9",
      "where": "Section 5.4, Table 6, ITO Density column",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "film_thickness",
      "label": "ITO coating thickness on the MISSE-9 sheets",
      "value": 10,
      "bound": "exact",
      "unit": "nm",
      "scope": "material",
      "conditions": {
        "form": "ITO coating on Kapton HN/Al and FEP/Ag/Inconel sheets",
        "basis": "approximately, as printed"
      },
      "method": "Stated in the description of the ITO test articles",
      "status": "ground",
      "note": "film_thickness is not in the property canon.",
      "source": "nasa-misse9",
      "where": "Section 2, description of the ITO coatings",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "sheet_resistance",
      "label": "Sheet resistance, ITO on Kapton HN/Al, ram flight sample, average",
      "value": 10820,
      "bound": "exact",
      "unit": "Ohm/square",
      "scope": "material",
      "conditions": {
        "sample": "M9R-S5 Flight, ITO/Kapton HN/Al, ram orientation",
        "exposure": "ram position, about 0.77 years in low Earth orbit",
        "measurement": "four-point probe"
      },
      "method": "Average of the measured values printed in Table 4 (printed as 10,820 Ohm/square)",
      "status": "flight",
      "note": "sheet_resistance is not in the property canon. The report says the value is still low enough to dissipate electrostatic charge.",
      "source": "nasa-misse9",
      "where": "Table 4, M9R-S5 Flight row, Average column; Section 5.2",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "sheet_resistance",
      "label": "Sheet resistance, ITO on Kapton HN/Al, unexposed material",
      "value": 5230,
      "bound": "exact",
      "unit": "Ohm/square",
      "scope": "material",
      "conditions": {
        "sample": "unexposed backup sheets of ITO/Kapton HN/Al",
        "basis": "overall average for unexposed material"
      },
      "method": "Overall average printed in Table 4 for the unexposed Kapton material",
      "status": "ground",
      "note": "The unexposed value used as the reference for the doubling reported in Section 5.2.",
      "source": "nasa-misse9",
      "where": "Table 4, ITO/Kapton HN/Al backup rows, Overall Average for Unexposed Material column",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "solar_absorptance",
      "label": "Solar absorptance, ITO/Kapton HN/Al, ram flight sample",
      "value": 0.42,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "sample": "M9R-S5 Flight, ram orientation",
        "control": "control sample 0.423 in the same figure",
        "exposure": "about 0.77 years in low Earth orbit",
        "spectrum": "AM0"
      },
      "method": "Integrated AM0 solar absorptance printed in the figure caption (printed as 0.420)",
      "status": "flight",
      "source": "nasa-misse9",
      "where": "Figure 9 caption; Table 5",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "solar_absorptance_change",
      "label": "Largest solar absorptance change, zenith flight sample",
      "value": 0.002,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "sample": "M9Z-S5 F, ITO/FEP/Ag/Inconel, zenith orientation",
        "exposure": "about 0.54 years in low Earth orbit"
      },
      "method": "Change stated in the text of the optical properties section, described as within error of the Cary data",
      "status": "flight",
      "note": "solar_absorptance_change is not in the property canon. The report states the change is within instrument error.",
      "source": "nasa-misse9",
      "where": "Section 5.3 (Optical Properties), text",
      "source_detail": {
        "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
        "id": "NASA/TM-20240002413; NTRS 20240002413",
        "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "optical_transmittance",
      "label": "Average optical transmittance, 400 to 800 nm, ITO film at 50 W",
      "value": 80.88,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "wavelength_range": "400 to 800 nm",
        "sputtering_power": "50 W",
        "thickness": "about 200 nm",
        "substrate": "glass"
      },
      "method": "Average printed in Table 1 of the paper",
      "status": "ground",
      "note": "optical_transmittance is not in the property canon. The same table gives 77.06 at 200 W.",
      "source": "sm-ito-2016",
      "where": "Table 1, 400 to 800 nm row, 50 W column",
      "source_detail": {
        "title": "Effect of Sputtering Power on Optical and Electrical Properties of Indium Tin Oxide Films (Her and Chang)",
        "id": "Sensors and Materials 28(9), 975-981 (2016), S&M 1259",
        "url": "https://sensors.myu-group.co.jp/sm_pdf/SM1259.pdf",
        "year": 2016,
        "kind": "paper",
        "license": "open access (MYU Research, Sensors and Materials)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Reducing gas atmosphere during metal-oxide gas sensing",
      "headline": "Reducing gases raise the conductance of SnO2, which is the sensing signal and not a damage mechanism.",
      "effect": "The review explains the gas response as a change in charge carriers at the oxide surface, and the conductance increases in a reducing atmosphere. It argues that removal of lattice oxygen is unlikely to be the main cause of the increase.",
      "rating": "unknown",
      "conditions": {
        "basis": "sensing use; the review does not rate damage",
        "form": "single-crystal and sensing SnO2 surfaces"
      },
      "source": "batzill-sno2-review",
      "where": "Sections on gas response and surface reduction"
    },
    {
      "environment": "Potassium, sodium, magnesium and chlorine trifluoride",
      "headline": "Reactive metals and chlorine trifluoride react violently with tin(IV) oxide.",
      "effect": "The PubChem incompatibility notes say that potassium or sodium reduce stannic oxide at gentle heat with incandescence, that heating with magnesium makes it explode, and that chlorine trifluoride reacts violently without flame.",
      "rating": "severe",
      "conditions": {
        "basis": "laboratory incompatibility notes, not a corrosion test",
        "form": "stannic oxide"
      },
      "source": "pubchem-sno2",
      "where": "Hazardous Reactivities and Incompatibilities (reference 24)"
    },
    {
      "environment": "Recommended storage in a closed container",
      "headline": "The SDS lists tin(IV) oxide as stable under recommended storage conditions.",
      "effect": "The SDS calls the material stable under recommended storage, and it is insoluble in water. It gives no degradation rate for the powder.",
      "rating": "none",
      "conditions": {
        "storage": "tightly closed container in a dry, well-ventilated place (SDS Section 7)",
        "form": "tin(IV) oxide powder"
      },
      "source": "isoflex-sno2-sds",
      "where": "Section 10, Chemical Stability row; Section 9, Solubility row"
    },
    {
      "environment": "Low Earth orbit atomic oxygen, ram and wake positions (MISSE-9 PCE-1)",
      "headline": "Atomic oxygen doubled the sheet resistance of the ram-facing ITO on Kapton, while the erosion yields were very low.",
      "effect": "After about 0.77 years in low Earth orbit, the ram ITO/Kapton HN/Al sheet resistance rose from 5230 to 10820 Ohm/square. The report still calls this low enough to dissipate static charge. The erosion yields were very low, and the wake Kapton sample stayed at 5000 Ohm/square before and after flight.",
      "rating": "low",
      "conditions": {
        "exposure": "ram, wake and zenith positions, 0.54 to 0.77 years in low Earth orbit",
        "mission": "MISSE-9 PCE-1"
      },
      "source": "nasa-misse9",
      "where": "Section 5.2 (Sheet Resistance), Section 5.4 (Erosion Yield), Table 4, Table 6, Section 6 (Conclusions)"
    },
    {
      "environment": "Solar ultraviolet in low Earth orbit (MISSE-9 flight samples)",
      "headline": "UV did not change the ITO sheets on Kapton, but it caused a small fluorescence on the FEP/Ag/Inconel sheets.",
      "effect": "Post-flight UV luminescence images showed that space exposure did not affect the response of the ITO-coated Kapton/Al sheets to UV. The UV caused a small amount of fluorescence in the ITO-coated FEP/Ag/Inconel material.",
      "rating": "low",
      "conditions": {
        "basis": "UV luminescence imaging, not a solar absorptance test",
        "mission": "MISSE-9 PCE-1"
      },
      "source": "nasa-misse9",
      "where": "UV luminescence section, Figures 6 to 8"
    },
    {
      "environment": "Strong oxidizers, strong acids, aluminium, magnesium and alkali metals (PubChem record)",
      "headline": "PubChem lists these materials as incompatible with the indium tin oxide record.",
      "effect": "The PubChem incompatibility entry names strong oxidizing agents, potassium, strong acids, aluminum, sodium or sodium oxides and magnesium. The Angstrom Sciences SDS prints no incompatible conditions.",
      "rating": "unknown",
      "conditions": {
        "basis": "compound record CID 57350325, which has a generic composition",
        "form": "indium tin oxide powder"
      },
      "source": "pubchem-ito",
      "where": "Hazardous Reactivities and Incompatibilities"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem reports that tin(IV) oxide does not meet GHS hazard criteria in 44.7% (356 of 796) of company reports. The other reports carry H335 (35.1%, may cause respiratory irritation) and H413 (17.3%, may cause long-lasting harmful effects to aquatic life).",
        "ghs": [
          "H335",
          "H413"
        ],
        "source": "pubchem-sno2",
        "where": "Safety and Hazards, GHS Classification (CID 16747781)"
      },
      {
        "text": "The ISOFLEX SDS (version 1.4, revised 10/18/2024) says the powder may be harmful if inhaled and may cause respiratory tract irritation, skin irritation and eye irritation, and lists it as not a dangerous substance under GHS.",
        "ghs": [],
        "source": "isoflex-sno2-sds",
        "where": "Section 2, Potential Health Effects and GHS rows"
      },
      {
        "text": "The Angstrom Sciences SDS for indium tin oxide lists H335 (may cause respiratory irritation) with the signal word Warning.",
        "ghs": [
          "H335"
        ],
        "source": "angstrom-ito-sds",
        "where": "Section 2, Signal Word and Hazard Statements"
      },
      {
        "text": "PubChem's indium tin oxide record (CID 57350325) lists H315 and H319 (skin and eye irritation) in aggregated notifications, and H372 (causes damage to organs through prolonged or repeated exposure, Danger) in one notification.",
        "ghs": [
          "H315",
          "H319",
          "H372"
        ],
        "source": "pubchem-ito",
        "where": "GHS Classification, notification blocks (references 5, 8 and 12)"
      },
      {
        "text": "PubChem's summary notes interstitial lung disease, called indium lung disease, in workers exposed to airborne ITO dust in production.",
        "ghs": [],
        "source": "pubchem-ito",
        "where": "Hazards Summary (reference 9)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Sheet resistance rise under atomic oxygen",
        "trigger": "Ram-facing ITO on Kapton HN/Al in low Earth orbit for about 0.77 years",
        "consequence": "Sheet resistance doubled from 5230 to 10820 Ohm/square. The report still considers the value low enough to dissipate static charge.",
        "severity": "moderate",
        "source": "nasa-misse9",
        "where": "Section 5.2 and Table 4; Section 6 (Conclusions)"
      },
      {
        "mode": "Unreliable sheet resistance on FEP/Ag/Inconel sheets",
        "trigger": "Post-flight four-point probe measurements on ITO-coated FEP/Ag/Inconel",
        "consequence": "Readings were very scattered, and a few were above 370000 Ohm/square. The report recommends measuring all samples again with calibrated equipment.",
        "severity": "moderate",
        "source": "nasa-misse9",
        "where": "Section 5.2 and Section 6 (Conclusions)"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Keep the container tightly closed in a dry, well-ventilated place, and provide exhaust ventilation where dust forms (SDS Section 7).",
        "source": "isoflex-sno2-sds",
        "where": "Section 7, Handling and Storage rows"
      },
      {
        "text": "Store the indium tin oxide in a cool, dry place in a tightly sealed container. Wash thoroughly after handling and do not blow dust off clothing or skin with compressed air.",
        "source": "angstrom-ito-sds",
        "where": "Section 7, Handling and Storage"
      },
      {
        "text": "Tin(IV) oxide is not combustible (PubChem fire hazards entry); its decomposition products under fire conditions are tin and tin oxides (SDS Section 5).",
        "source": "pubchem-sno2",
        "where": "Fire Hazards entry; ISOFLEX SDS Section 5 for decomposition products"
      }
    ],
    "mitigations": [
      {
        "text": "For spills, use a HEPA air filter to collect the dust and place it in a closed container, taking care not to raise dust.",
        "source": "angstrom-ito-sds",
        "where": "Section 6, Accidental Release Measures"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Metal-oxide gas sensors",
      "example": "A surface-science review uses tin dioxide as the model system for metal-oxide gas sensing materials, and explains the gas response as a change in charge carriers at the oxide surface.",
      "source": "batzill-sno2-review",
      "where": "Abstract and introduction to the gas-sensing discussion"
    },
    {
      "application": "electronics-and-chips",
      "device": "Dopant in indium tin oxide transparent electrodes",
      "example": "The standard ITO sputtering target is 90 wt% In2O3 and 10 wt% SnO2, so SnO2 is the dopant in the transparent conductor used for flat displays and touch sensors.",
      "source": "sputtertargets-ito",
      "where": "Standard Composition row; Typical Applications"
    },
    {
      "application": "electronics-and-chips",
      "device": "Transparent electrodes in flat-panel displays (ITO)",
      "example": "USGS reports that ITO thin-film coatings are used mainly for electrically conductive purposes in flat-panel displays, most commonly liquid crystal displays.",
      "source": "usgs-indium-2026",
      "where": "Domestic Production and Use paragraph"
    },
    {
      "application": "thermal-control",
      "device": "ITO-coated thermal control sheets (Kapton HN/Al and FEP/Ag/Inconel) on an external ISS tray",
      "example": "The MISSE-9 report concludes that all ITO-coated sheets performed well and were not noticeably damaged in low Earth orbit, implying they are suitable as thermal control sheet materials.",
      "source": "nasa-misse9",
      "where": "Section 6 (Conclusions)"
    },
    {
      "application": "thermal-control",
      "device": "Charge-dissipating ITO coating on thermal control sheets",
      "example": "The report says the ITO-coated Kapton sheet's final resistance of 10820 Ohm/square is believed to be low enough to dissipate electrostatic charges.",
      "source": "nasa-misse9",
      "where": "Section 6 (Conclusions)"
    },
    {
      "application": "solar-arrays",
      "device": "Transparent electrodes in thin-film solar cells (supplier application)",
      "example": "The vendor lists thin-film solar cells, including heterojunction and perovskite cells, among the typical applications of its standard ITO rotary target.",
      "source": "sputtertargets-ito",
      "where": "Typical Applications paragraph"
    }
  ],
  "supply": [
    {
      "subject": "Tin (for SnO2 and ITO)",
      "producers": [
        {
          "country": "China",
          "share_percent": 24.5,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 21,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 11.4,
          "year": 2025
        },
        {
          "country": "Brazil",
          "share_percent": 9.7,
          "year": 2025
        },
        {
          "country": "Burma",
          "share_percent": 4.1,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (tin is on the final list)",
          "listed": true
        }
      ],
      "recycling": "USGS: about 17,000 tons of tin from old and new scrap was estimated to have been recycled in 2025, 22% of apparent consumption in the United States.",
      "substitutes": [
        "USGS: aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans and containers, and epoxy resins can replace tin in solder."
      ],
      "source": "usgs-tin-2026",
      "where": "World Mine Production and Reserves table, 2025e (shares calculated by Space Mushroom against the 290000 t world total; China 71000, Indonesia 61000, Peru 33000, Brazil 28000, Burma 12000); Recycling; Substitutes; critical list from usgs-crit-2025"
    },
    {
      "subject": "Indium (for ITO)",
      "producers": [
        {
          "country": "China",
          "share_percent": 70,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (indium is on the final list, used in flat-panel displays and touchscreens)",
          "listed": true
        }
      ],
      "recycling": "USGS: indium is most commonly recovered from ITO scrap in Japan and the Republic of Korea; quantities recovered are not reported.",
      "substitutes": [
        "USGS: antimony tin oxide, carbon nanotube coatings, PEDOT, copper or silver nanowires and graphene have been developed as alternatives to ITO in some uses."
      ],
      "source": "usgs-indium-2026",
      "where": "Domestic Production and Use; World Resources; Recycling; Substitutes. The 70% share is printed in the text as China accounting for 70% of the world total (year assumed to be the 2025 data year of the report)"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5 (version 1.4, revision date 10/18/2024)",
      "type": "sds",
      "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
      "year": 2024
    },
    {
      "title": "PubChem: Tin(IV) oxide (CID 16747781), GHS classification and physical properties",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/16747781",
      "year": 2026
    },
    {
      "title": "Surface Science Studies of Gas Sensing Materials: SnO2 (open access, Sensors 2006)",
      "type": "paper",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC3909400/",
      "year": 2006
    },
    {
      "title": "Effect of Sputtering Power on Optical and Electrical Properties of Indium Tin Oxide Films (Sensors and Materials, open access)",
      "type": "paper",
      "url": "https://sensors.myu-group.co.jp/sm_pdf/SM1259.pdf",
      "year": 2016
    },
    {
      "title": "Space Exposure of Indium Tin Oxide Coatings (NASA/TM-20240002413)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
      "year": 2024
    },
    {
      "title": "Sputter Targets: ITO rotary sputtering target specification (ST11192)",
      "type": "datasheet",
      "url": "https://www.sputtertargets.net/st11192-indium-tin-oxide-ito-rotary-sputtering-target/",
      "year": 2026
    },
    {
      "title": "Angstrom Sciences safety data sheet: Indium Tin Oxide",
      "type": "sds",
      "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Indium%20Tin%20Oxide.pdf",
      "year": 2015
    },
    {
      "title": "PubChem: Indium tin oxide record (CID 57350325), GHS classification and reactivity",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/57350325",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Tin",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Indium",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf",
      "year": 2026
    },
    {
      "title": "USGS: About the 2025 List of Critical Minerals (final list)",
      "type": "report",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025
    }
  ],
  "gaps": [
    "A Japanese government GHS listing (NITE) that classifies ITO as carcinogenic (H350) appeared in a search result, but both NITE pages returned 404 in this run. It is not used. Check it before any work that involves repeated inhalation of ITO powder.",
    "Crystal system and lattice constants of SnO2 were not printed in any source opened for this profile. The review discusses rutile-type surfaces, but the body text gives no crystal system.",
    "No refractive index of SnO2 with a stated wavelength was found. PubChem prints 1.997 and 2.093 with no wavelength or source, so they are not used.",
    "No open paper with a measured SnO2 film resistivity or gas-sensor response value was opened. The review used for gas sensing is a surface-science review with no sensor response numbers.",
    "The PubChem record CID 16747781 also carries one H372 notification (Danger, repeated exposure) whose substance is not named in the record. It is not used.",
    "The PubChem ITO record (CID 57350325, formula InOSn) is a generic composition record. Its hazard and reactivity entries may describe indium compounds rather than ITO film, so they are flagged rather than treated as ITO-specific.",
    "The indium tin oxide CAS number was not read in a source opened for this profile, so the identity block gives the SnO2 CAS only.",
    "Crustal abundance of tin and indium was not read in a source opened for this profile (USGS PP 1802-A not fetched).",
    "The EU critical raw materials list was not checked for tin or indium, so no EU list entry is given.",
    "Mine shares for tin are calculated by Space Mushroom from the USGS 2025e table against the 290000 t world total. Indium producer share is the printed 70% statement, not a table.",
    "Bulk ITO strength, fracture toughness and thermal conductivity were not read in any source opened. The ITO properties above describe thin films on polymer sheets and sputtered films, not dense ceramic parts.",
    "The vendor page lists target resistivity only as High (Insulating), with no number, so it is not used.",
    "The MISSE-9 atomic oxygen erosion yields are printed in exponent form, so the numeric values are left out of properties. The corrosion entry describes them qualitatively.",
    "The sputtering paper (Sensors and Materials 2016) prints the 50 W film resistivity as 5.702 x 10 to the minus 4 Ohm cm with a Unicode minus sign, so the value check could not match it. The property is left out until it is checked by hand. The text (2.376) and Table 3 (23.76) also conflict at 200 W.",
    "Vacuum outgassing (TML and CVCM) and radiation results for SnO2 or ITO were not found in a source opened for this profile."
  ],
  "story": {
    "why": "Tin(IV) oxide is a white, water-insoluble oxide with a bulk band gap of 3.6 eV. Its gas-sensing behavior comes from charge carriers at the surface, which the surface-science review describes in detail. Indium tin oxide adds 10 wt% SnO2 to indium oxide to make a transparent conductive film. The MISSE-9 flight tested ITO sheets in low Earth orbit and the sheets kept usable sheet resistance and low solar absorptance, which makes the film a candidate for thermal control and charge dissipation.",
    "uses": [
      {
        "where": "Metal-oxide gas sensors",
        "line": "A surface-science review uses tin dioxide as the model system for metal-oxide gas sensing materials, and explains the gas response as a change in charge carriers at the oxide surface."
      },
      {
        "where": "Transparent conductor for displays",
        "line": "The standard ITO target is 90 wt% In2O3 and 10 wt% SnO2. USGS reports that ITO coatings are used mainly in flat-panel displays, most commonly liquid crystal displays."
      },
      {
        "where": "Thermal control sheets in orbit",
        "line": "In the MISSE-9 test, ITO-coated sheets were not noticeably damaged by about 0.54 to 0.77 years in low Earth orbit, and the authors judged them suitable as thermal control sheet materials."
      }
    ],
    "can_do": [
      {
        "label": "Transparency",
        "line": "A DC-sputtered ITO film made at 50 W averaged 80.88% transmittance from 400 to 800 nm, on a glass substrate about 200 nm thick.",
        "scope": "material",
        "value": "80.88"
      },
      {
        "label": "Heat",
        "line": "Tin(IV) oxide melts at 1630 °C according to the SDS, and the SDS lists the powder as stable under recommended storage.",
        "scope": "material",
        "value": "1630 °C"
      },
      {
        "label": "Low absorptance in orbit",
        "line": "The ram-facing ITO on Kapton reached a solar absorptance of 0.42 on the flight, against 0.423 for the control sample.",
        "scope": "material",
        "value": "0.42"
      },
      {
        "label": "Charge dissipation",
        "line": "The report says the flown ITO on Kapton kept a sheet resistance low enough to dissipate electrostatic charge.",
        "scope": "material",
        "value": "10820 Ohm/square"
      }
    ],
    "compare": "SnO2 is an insoluble oxide with a melting point of 1630 °C and a density of 6.95 g/mL. Indium tin oxide shares this oxide base, but its sputtered films are used for electrical rather than structural properties, with a visible transmittance of 80.88% at 50 W. The table compares density, melting point and film transmittance across the two forms.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Film transmittance",
        "benchmark": "optical_transmittance",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep the powder in a tightly closed container in a dry, well-ventilated place, with exhaust ventilation where dust forms.",
      "Do not blow dust off clothing or skin with compressed air. Wash thoroughly after handling.",
      "Use a HEPA filter for spills, and place the collected dust in a closed container."
    ],
    "good_for": [
      "Transparent conductive films for displays and thin-film solar cells (ITO). The standard target has a density of 7.13 g/cm3 or more and 99.99% purity on an oxide basis.",
      "Gas-sensing layers based on SnO2, which the review uses as the model metal-oxide sensing material.",
      "Thermal control sheets with a low solar absorptance, shown in the MISSE-9 flight test."
    ],
    "watch_out": [
      "Indium supply: China produces 70% of world indium, and USGS reports new export restrictions on indium from February 2025.",
      "Sheet resistance can double under atomic oxygen on the ram side of the spacecraft, and some measured values scatter widely.",
      "Irritation and lung disease in workers who breathe ITO dust. The NITE carcinogenicity listing could not be checked in this run.",
      "Reducing gases change the conductance of SnO2, which is the sensing signal, so the material should not be used as a stable resistor without checking the atmosphere."
    ],
    "verdict": "SnO2 and ITO are useful oxide materials for transparent conductors, gas sensing and low-absorptance thermal coatings. The space record is limited to thin ITO films on polymer sheets for about 0.77 years in low Earth orbit, and the main supply and health risks are indium-related.",
    "recipe": {
      "line": "SnO2 is tin(IV) oxide, one tin and two oxygen per formula unit. Indium tin oxide (ITO) is mostly indium(III) oxide with 10 wt% SnO2 in the standard sputtering target, which is 90 wt% In2O3 and 10 wt% SnO2.",
      "parts": [
        {
          "name": "Tin",
          "symbol": "Sn",
          "role": "The metal in SnO2. The review describes surface tin as changing between Sn(IV) and Sn(II) states, which matters for gas sensing."
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Two oxygen per formula unit of SnO2."
        },
        {
          "name": "Indium(III) oxide",
          "symbol": "In2O3",
          "role": "The host oxide in the standard ITO target (90 wt%). Its film is sputtered as the transparent conductor.",
          "share_percent": 90
        },
        {
          "name": "Tin(IV) oxide",
          "symbol": "SnO2",
          "role": "The dopant in the standard ITO target (10 wt%) and the active oxide in tin-oxide gas sensors.",
          "share_percent": 10
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people, tin(IV) oxide powder",
        "lead": "The SDS calls the powder not a dangerous substance under GHS, but it may irritate the eyes, skin and airways, and PubChem reports an H335 classification in some company reports.",
        "points": [
          {
            "label": "The powder",
            "line": "The SDS says the powder may be harmful if inhaled and may irritate the respiratory tract, skin and eyes. PubChem reports that 44.7% of company reports do not meet GHS criteria."
          },
          {
            "label": "Dust",
            "line": "Use exhaust ventilation where dust forms. The stannosis entry in PubChem describes a benign lung change from breathing tin dust or fume."
          }
        ],
        "level": 1,
        "verdict": "Irritant dust; not a GHS hazard in most reports"
      },
      {
        "title": "For people, indium tin oxide",
        "lead": "The indium tin oxide supplier SDS classes the material as a respiratory irritant, and PubChem records lung disease in workers who breathed ITO dust.",
        "points": [
          {
            "label": "Respiratory",
            "line": "The Angstrom Sciences SDS lists H335 with the signal word Warning, and PubChem's record also lists H315, H319 and one H372 notification."
          },
          {
            "label": "Lung disease",
            "line": "PubChem's summary reports indium lung disease in workers exposed to airborne ITO dust in production."
          }
        ],
        "level": 1,
        "verdict": "Irritant; lung disease reported in ITO workers"
      },
      {
        "title": "In orbit, ITO coatings",
        "points": [
          {
            "label": "Sheet resistance",
            "line": "On the MISSE-9 flight, the ram-facing ITO on Kapton doubled its sheet resistance, from 5230 to 10820 Ohm/square, after about 0.77 years in low Earth orbit."
          },
          {
            "label": "Scatter",
            "line": "The FEP/Ag/Inconel sheets gave very scattered readings, with some above 370000 Ohm/square, so the report asks for a repeat with calibrated equipment."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 15,
    "unreachable": 1,
    "caveats": 4,
    "note": "Read by an AI assistant on 2026-10-26 from the pages and PDFs fetched in that run. The NITE page (ITO carcinogenicity listing) returned 404 and is not used. Caveats: the ITO values are thin-film or vendor-target values, not bulk ceramic; the SnO2 band gap is an expected bulk value from a review; the 200 W resistivity conflicts inside the sputtering paper."
  },
  "sources": {
    "isoflex-sno2-sds": {
      "title": "ISOFLEX safety data sheet: Tin(IV) oxide, CAS 18282-10-5",
      "id": "Version 1.4, revision date 10/18/2024",
      "url": "https://isoflex.com/cn/docman-all-categories/sds/614-tin-oxide-rev-3/file",
      "year": 2024,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "pubchem-sno2": {
      "title": "PubChem compound record, Tin(IV) oxide (CID 16747781)",
      "id": "CID 16747781; formula O2Sn",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/16747781/JSON",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "batzill-sno2-review": {
      "title": "Surface Science Studies of Gas Sensing Materials: SnO2",
      "id": "Sensors 6(10), 1345-1366 (2006), PMC3909400",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC3909400/",
      "year": 2006,
      "kind": "paper",
      "license": "open access (PMC)"
    },
    "sm-ito-2016": {
      "title": "Effect of Sputtering Power on Optical and Electrical Properties of Indium Tin Oxide Films (Her and Chang)",
      "id": "Sensors and Materials 28(9), 975-981 (2016), S&M 1259",
      "url": "https://sensors.myu-group.co.jp/sm_pdf/SM1259.pdf",
      "year": 2016,
      "kind": "paper",
      "license": "open access (MYU Research, Sensors and Materials)"
    },
    "nasa-misse9": {
      "title": "Space Exposure of Indium Tin Oxide Coatings (NASA MISSE-9 PCE-1)",
      "id": "NASA/TM-20240002413; NTRS 20240002413",
      "url": "https://ntrs.nasa.gov/api/citations/20240002413/downloads/TM-20240002413.pdf",
      "year": 2024,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "sputtertargets-ito": {
      "title": "Sputter Targets: Indium tin oxide (ITO) rotary sputtering target, standard 90/10",
      "id": "SKU ST11192 (page undated; retrieved 2026-10-26)",
      "url": "https://www.sputtertargets.net/st11192-indium-tin-oxide-ito-rotary-sputtering-target/",
      "year": 2026,
      "kind": "datasheet",
      "license": "supplier page, linked not reproduced"
    },
    "angstrom-ito-sds": {
      "title": "Angstrom Sciences safety data sheet: Indium Tin Oxide",
      "id": "Revision date printed as 076/21/15 (garbled in the PDF)",
      "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Indium%20Tin%20Oxide.pdf",
      "year": 2015,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "pubchem-ito": {
      "title": "PubChem compound record, Indium tin oxide (CID 57350325)",
      "id": "CID 57350325; formula InOSn (generic composition record)",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/57350325",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "usgs-tin-2026": {
      "title": "Mineral Commodity Summaries 2026, Tin",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-indium-2026": {
      "title": "Mineral Commodity Summaries 2026, Indium",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit-2025": {
      "title": "About the 2025 List of Critical Minerals (USGS, final list)",
      "id": "Final 2025 List of Critical Minerals",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/tin-oxide/"
}