{
  "spore": "profile",
  "id": "lead-glass",
  "spore_version": "0.2",
  "family": "glass-and-composites",
  "name": "Lead glass",
  "abbreviation": "Lead glass",
  "role": "transparent radiation-shielding glass",
  "category": "shielding",
  "type": "spot-shields",
  "summary": "Lead glass is a transparent glass in which lead oxide is a major ingredient. NIST's assumed composition for \"Glass, Lead\" is 75.19% lead by weight, with a density of 6.220 g/cm3 (nominal). SCHOTT's RD 50 shielding glass has a minimum density of 5.05 g/cm3 and at least 65% lead oxide, and a 5.0 mm sheet transmits 85% of visible light, per SCHOTT's technical data.\n",
  "best_for": "Transparent X-ray and gamma shielding for windows and viewing panels, such as CT and PET facilities and analytical equipment",
  "weakest_at": "Heavy (RS 520 has a minimum density of 5.18 g/cm3), contains lead, and no flight or space use was found in this run",
  "identity": {
    "formula": "Lead-rich oxide glass. NIST's assumed composition for Glass, Lead (by weight): Pb 0.751938, O 0.156453, Si 0.080866, Ti 0.008092, As 0.002651",
    "designations": [],
    "source": "nist-table2",
    "where": "NIST Table 2, row Glass, Lead, composition column (Z: fraction by weight, 82: 0.751938). The composition is an assumed example for NIST's attenuation tables; SCHOTT's products are defined by the manufacturer and their lead oxide contents are given as minimums."
  },
  "tags": {
    "environments": [],
    "stresses": [
      "total-radiation-dose"
    ],
    "applications": [
      "radiation-shielding"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density of NIST's assumed lead glass composition",
      "value": 6.22,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "composition": "NIST assumed mass fractions Pb 0.751938, O 0.156453, Si 0.080866, Ti 0.008092, As 0.002651",
        "note_on_value": "nominal value; NIST says some density values are only nominal"
      },
      "method": "Density column of NIST Table 2, printed as 6.220E+00 g/cm3",
      "status": "ground",
      "note": "A single assumed composition used for X-ray attenuation calculations, not a measured value for any SCHOTT or other product.",
      "source": "nist-table2",
      "where": "Table 2, row Glass, Lead, Density (g/cm3) column",
      "source_detail": {
        "title": "X-Ray Mass Attenuation Coefficients, Table 2: Material constants and composition assumed in the present evaluations",
        "id": "NIST, Table 2 (tab2.html)",
        "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/tab2.html",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NIST)"
      }
    },
    {
      "benchmark": "density",
      "label": "Minimum density of RD 50 radiation shielding glass",
      "value": 5.05,
      "bound": "lower",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "product": "RD 50",
        "condition": "as-delivered condition"
      },
      "method": "Technical data table, printed as \"≥ 5.05\" density in g/cm3",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 50 technical data table, density row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Minimum density of RD 30 radiation shielding glass",
      "value": 3.13,
      "bound": "lower",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "product": "RD 30",
        "condition": "as-delivered condition"
      },
      "method": "Technical data table, printed as \"≥ 3.13\" density in g/cm3",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 30 technical data table, density row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Minimum density of RS 520 radiation shielding glass",
      "value": 5.18,
      "bound": "lower",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "product": "RS 520, nuclear series",
        "note_on_value": "labelled Minimum density"
      },
      "method": "General characteristics table, printed as minimum density in g/cm3",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Characteristics of Radiation Shielding Glasses table, Minimum density row, RS 520 column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_oxide_content",
      "label": "Lead oxide content of RD 50",
      "value": 65,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "RD 50",
        "basis": "as printed (no basis stated)"
      },
      "method": "Technical data table, printed as \"≥ 65%\" lead oxide content (PbO)",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 50 technical data table, Lead oxide content (PbO) row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_oxide_content",
      "label": "Lead oxide content of RD 30",
      "value": 22,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "RD 30",
        "basis": "as printed (no basis stated)"
      },
      "method": "Technical data table, printed as \"≥ 22%\" lead oxide content (PbO)",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 30 technical data table, Lead oxide content (PbO) row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_oxide_content",
      "label": "Lead oxide content of RS 520 (synthesis composition)",
      "value": 71,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "product": "RS 520",
        "basis": "PbO weight-% of the synthesis composition, not of the finished glass"
      },
      "method": "Characteristics of Radiation Shielding Glasses table, PbO content in weight-% from synthesis",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Characteristics of Radiation Shielding Glasses table, PbO content row, RS 520 column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "refractive_index",
      "value": 1.79,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "product": "RD 50",
        "temperature": "20 °C",
        "wavelength": "nD (sodium d-line, as the page labels it)"
      },
      "method": "Technical data table, printed as refractive index nD at 20 °C",
      "status": "ground",
      "note": "This is the RD 50 figure. The same SCHOTT page gives nd 1.81 for RS 520, which is a different product and is not used as a lead glass value here.",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 50 technical data table, Refractive index row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "light_transmittance",
      "label": "Light transmittance of RD 50 at 5.0 mm",
      "value": 85,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "RD 50",
        "thickness": "5.0 mm"
      },
      "method": "Technical data table, printed as light transmittance (d = 5.0 mm)",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 50 technical data table, Light transmittance row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "light_transmittance",
      "label": "Light transmittance of RD 30 at 6.0 mm",
      "value": 90.5,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "RD 30",
        "thickness": "6.0 mm"
      },
      "method": "Technical data table, printed as light transmittance (d = 6.0 mm)",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Technical data for RD 30 technical data table, Light transmittance row",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_equivalent",
      "label": "Lead equivalent of RD 50 at 80 kV",
      "value": 1.5,
      "bound": "exact",
      "unit": "mm Pb",
      "scope": "material",
      "conditions": {
        "product": "RD 50",
        "glass_thickness": "5.0 to 7.0 mm (minimum to maximum thickness of the range)",
        "tube_voltage": "80 kV"
      },
      "method": "Lead-equivalent table for X-ray quality, printed in mm Pb",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "RD 50 lead-equivalents table for X-ray quality, row 5.0 to 7.0 mm, 80 kV column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_equivalent",
      "label": "Lead equivalent of RD 30 at 6.0 mm",
      "value": 0.5,
      "bound": "lower",
      "unit": "mm Pb",
      "scope": "material",
      "conditions": {
        "product": "RD 30",
        "glass_thickness": "6.0 plus or minus 0.25 mm",
        "tube_voltage": "80 kV"
      },
      "method": "Lead-equivalent table, printed as \"≥ 0.5\" in mm Pb (the same value is printed for 50 to 150 kV)",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "RD 30 lead-equivalents table, row 6.0 plus or minus 0.25 mm, 80 kV column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "linear_attenuation_coefficient",
      "label": "Linear attenuation coefficient of RS 520 at 0.2 MeV",
      "value": 3.54,
      "bound": "exact",
      "unit": "cm-1",
      "scope": "material",
      "conditions": {
        "product": "RS 520",
        "energy": "0.2 MeV"
      },
      "method": "Linear attenuation coefficients table, printed in cm-1",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Linear attenuation coefficients table, E = 0.2 MeV row, RS 520 column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "linear_attenuation_coefficient",
      "label": "Linear attenuation coefficient of RS 520 at 0.662 MeV (137Cs line)",
      "value": 0.5,
      "bound": "exact",
      "unit": "cm-1",
      "scope": "material",
      "conditions": {
        "product": "RS 520",
        "energy": "0.662 MeV (137Cs)"
      },
      "method": "Linear attenuation coefficients table, printed in cm-1",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Linear attenuation coefficients table, E = 0.662 MeV (137Cs) row, RS 520 column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "linear_attenuation_coefficient",
      "label": "Linear attenuation coefficient of RS 520 at 1.25 MeV (60Co line)",
      "value": 0.3,
      "bound": "exact",
      "unit": "cm-1",
      "scope": "material",
      "conditions": {
        "product": "RS 520",
        "energy": "1.25 MeV (60Co)"
      },
      "method": "Linear attenuation coefficients table, printed in cm-1",
      "status": "ground",
      "source": "schott-rs-rd",
      "where": "Linear attenuation coefficients table, E = 1.25 MeV (60Co) row, RS 520 column",
      "source_detail": {
        "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
        "id": "SCHOTT AG, radiation shielding glasses, technical details page",
        "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
        "year": 2026,
        "kind": "datasheet",
        "license": "manufacturer web page, cited not reproduced"
      }
    },
    {
      "benchmark": "mass_attenuation_coefficient",
      "label": "Mass attenuation coefficient of lead glass at 0.1 MeV",
      "value": 4.216,
      "bound": "exact",
      "unit": "cm2/g",
      "scope": "material",
      "conditions": {
        "composition": "NIST assumed Glass, Lead composition",
        "photon_energy": "0.1 MeV"
      },
      "method": "Mass attenuation coefficient (mu/rho) printed in the NIST table for Glass, Lead",
      "status": "ground",
      "source": "nist-glass-lead",
      "where": "Table for Glass, Lead, row 1.00000E-01 MeV, mu/rho column",
      "source_detail": {
        "title": "X-Ray Mass Attenuation Coefficients: Glass, Lead (NIST)",
        "id": "NIST XCOM, Glass, Lead (ComTab/glass.html)",
        "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/glass.html",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NIST)"
      }
    },
    {
      "benchmark": "mass_attenuation_coefficient",
      "label": "Mass attenuation coefficient of lead glass at the lead K absorption edge",
      "value": 5.824,
      "bound": "exact",
      "unit": "cm2/g",
      "scope": "material",
      "conditions": {
        "composition": "NIST assumed Glass, Lead composition",
        "photon_energy": "0.0880045 MeV (lead K absorption edge, as printed)"
      },
      "method": "Mass attenuation coefficient (mu/rho) printed in the NIST table for Glass, Lead, printed as 5.824E+00",
      "status": "ground",
      "source": "nist-glass-lead",
      "where": "Table for Glass, Lead, row 8.80045E-02 MeV (82 K), mu/rho column",
      "source_detail": {
        "title": "X-Ray Mass Attenuation Coefficients: Glass, Lead (NIST)",
        "id": "NIST XCOM, Glass, Lead (ComTab/glass.html)",
        "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/glass.html",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NIST)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of a laboratory special lead glass (sample 1, seven oxides)",
      "value": 2.73,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "composition": "sample (1) of Table 1, seven oxides with lead oxide 28 wt% in the batch",
        "form": "melted and cooled in the laboratory, measured as a sample"
      },
      "method": "Density of special lead glass as printed in the text, calculated by weighing the sample and measuring its volume",
      "status": "ground",
      "note": "A small laboratory glass from a 2006 study, not a SCHOTT product. The same paper gives 6.22 g/cm3 for standard lead glass (Hubbell 1982).",
      "source": "mosul-fathi-2006",
      "where": "Experimental methods section, paragraph on density (sentence beginning The density of special lead glass is)",
      "source_detail": {
        "title": "Mass Attenuation of Gamma Photons in Special Lead Glass that Can be Used in Radiation Shielding Windows",
        "id": "Raf. Jour. Sci., Vol. 17, No. 2 (Physics, Special Issue), pp. 6-12, 2006",
        "url": "https://jamh.uomosul.edu.iq/index.php/rsci/article/download/47397/47135/47440",
        "year": 2006,
        "kind": "paper",
        "license": "journal PDF, cited not reproduced"
      }
    },
    {
      "benchmark": "lead_oxide_content",
      "label": "Lead oxide content of special lead glass sample (1) in the batch",
      "value": 28,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "composition": "sample (1), seven-oxide special lead glass",
        "basis": "weight ratio of lead oxide in the batch, not measured in the finished glass"
      },
      "method": "Weight ratio of lead oxide in sample (1), as printed in Table 1 (Lead Oxide row, 28%)",
      "status": "ground",
      "note": "Batch weight ratio of a laboratory glass. It is below the at least 65% lead oxide that SCHOTT gives for RD 50.",
      "source": "mosul-fathi-2006",
      "where": "Table 1, Lead Oxide row, sample (1) column",
      "source_detail": {
        "title": "Mass Attenuation of Gamma Photons in Special Lead Glass that Can be Used in Radiation Shielding Windows",
        "id": "Raf. Jour. Sci., Vol. 17, No. 2 (Physics, Special Issue), pp. 6-12, 2006",
        "url": "https://jamh.uomosul.edu.iq/index.php/rsci/article/download/47397/47135/47440",
        "year": 2006,
        "kind": "paper",
        "license": "journal PDF, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Water and humidity (hydrolytic attack, DIN ISO 719 test)",
      "headline": "SCHOTT lists a hydrolytic class of HGB 1 for RD 50 and HGB 3 for RD 30.",
      "effect": "The technical data for both RD glasses give a hydrolytic class under DIN ISO 719 (RD 50 HGB 1, RD 30 HGB 3). The page gives no corrosion rate, test duration or the meaning of the class in detail, so the result is not quantified here.",
      "rating": "low",
      "conditions": {
        "products": "RD 50 and RD 30",
        "test": "DIN ISO 719 hydrolytic class, as printed"
      },
      "source": "schott-rs-rd",
      "where": "Technical data tables for RD 30 and RD 50, Hydrolytic class row"
    },
    {
      "environment": "Ionising radiation (browning, or discoloration, of the glass)",
      "headline": "SCHOTT gives a discoloration total-dose limit of 1 × 10^8 Gy or more for two RS glasses, and says cerium oxide doping prevents browning.",
      "effect": "The application-limit table lists a discoloration total-dose limit of 1 × 10^8 Gy for RS 253 G18 and above 1 × 10^8 Gy for RS 323 G19. The page says these two glasses are doped with cerium dioxide, which prevents solarization (browning) from high-energy ionization. The table gives no discoloration limit for RS 253, RS 360 or RS 520.",
      "rating": "moderate",
      "conditions": {
        "products": "RS 253 G18 and RS 323 G19",
        "exposure": "total dose in Gy",
        "note_on_superscripts": "the page flattens superscripts; read 1 × 108 as 1 × 10^8 Gy"
      },
      "source": "schott-rs-rd",
      "where": "Application limits table, discoloration row; Use, Radiation Resistance and Solarization section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Trace Sciences SDS for lead(II) oxide (CAS 1317-36-8, PbO), the lead-oxide raw material of lead glass: signal word Danger; H302 + H332, H351, H360, H362, H372 (central nervous system, kidney, blood), H400 and H410. The SDS is for the powder, not for finished glass, and no GHS classification of the finished glass was found.",
        "ghs": [
          "H302",
          "H332",
          "H351",
          "H360",
          "H362",
          "H372",
          "H400",
          "H410"
        ],
        "source": "trace-pbo-sds",
        "where": "Section 2.1 GHS classification and Section 2.2 hazard statements"
      },
      {
        "text": "The same SDS gives precautions for the powder: avoid breathing dust or fume (P260), store locked up (P405), avoid release to the environment (P273) and dispose of contents at an approved plant (P501).",
        "ghs": [],
        "source": "trace-pbo-sds",
        "where": "Section 2.2 precautionary statements"
      }
    ],
    "failure_risks": [
      {
        "mode": "Induced discharge in RS glasses above a total dose threshold",
        "trigger": "Total radiation dose of 1 × 10^3 Gy for RS 253, RS 360 and RS 520 (the table's discharge limit)",
        "consequence": "SCHOTT's application-limit table lists this total-dose limit for induced discharge. The page does not describe the mechanism. The superscripts are flattened on the page and read as 1 × 10^3 Gy.",
        "severity": "moderate",
        "source": "schott-rs-rd",
        "where": "Application limits table, discharge row (footnote: discharge threshold, induced discharge)"
      },
      {
        "mode": "Browning (discoloration) of RS glasses at very high total dose",
        "trigger": "Total dose at or above 1 × 10^8 Gy for RS 253 G18 and RS 323 G19",
        "consequence": "The table lists a discoloration limit of 1 × 10^8 Gy for RS 253 G18 and above 1 × 10^8 Gy for RS 323 G19. Cerium oxide doping is said to prevent the browning. Discoloration in other RS glasses is not limited by a figure on the page.",
        "severity": "low",
        "source": "schott-rs-rd",
        "where": "Application limits table, discoloration row; Use, Radiation Resistance and Solarization section"
      }
    ],
    "side_effects": [
      {
        "text": "Lead glass that is broken or ground to powder releases lead-containing particles. The PbO SDS asks users to avoid breathing dust and to collect spillage. No glass-specific exposure limit was read in this run.",
        "affects": "People in the room and the disposal stream",
        "source": "trace-pbo-sds",
        "where": "Section 2.2 (P260, P391) and Section 7"
      }
    ],
    "handling": [
      {
        "text": "SCHOTT describes RD 30 as scratch-resistant, non-flammable and easier to clean than acrylic.",
        "source": "schott-rs-rd",
        "where": "Use section, RD 30 paragraph"
      },
      {
        "text": "The PbO SDS asks for the container to be stored locked up and waste to go to an approved disposal plant.",
        "source": "trace-pbo-sds",
        "where": "Section 2.2 (P405, P501)"
      }
    ],
    "mitigations": [
      {
        "text": "Cerium oxide doping (RS 253 G18 and RS 323 G19) is said to prevent browning from high-energy ionization.",
        "source": "schott-rs-rd",
        "where": "Use, Radiation Resistance and Solarization section; RS table composition rows"
      }
    ]
  },
  "uses": [
    {
      "application": "radiation-shielding",
      "device": "Viewing windows, doors and panoramic glazing at CT and PET facilities and analytical equipment (RD 50)",
      "example": "SCHOTT says RD 50 is supplied as stock sheets or custom panels with boreholes and cut-outs, and is suited to PET and CT scan facilities and to windows, doors and panoramic glazing for analytical equipment.",
      "source": "schott-variants",
      "where": "Product variants page, RD 50 use description"
    },
    {
      "application": "radiation-shielding",
      "device": "Mammography shielding panels (RD 30)",
      "example": "SCHOTT says RD 30 is developed for analogue and digital mammography, is available in large sizes and can be bent or moulded.",
      "source": "schott-variants",
      "where": "Product variants page, RD 30 use description"
    },
    {
      "application": "radiation-shielding",
      "device": "Shielding window frames for nuclear energy and nuclear waste facilities (RS series)",
      "example": "SCHOTT says the RS glasses were developed for nuclear energy production and nuclear waste treatment, and are supplied as finished blocks, plates or custom castings for shielding window frames.",
      "source": "schott-variants",
      "where": "Product variants page, RS series note"
    }
  ],
  "supply": [
    {
      "subject": "Lead",
      "abundance": "Not read in this run (no crustal abundance figure opened for lead).",
      "producers": [
        {
          "country": "China",
          "share_percent": 42.2,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 10.7,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 6.4,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 5.8,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 4.4,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (lead added in the final 2025 list)",
          "listed": true
        },
        {
          "list": "EU critical raw materials list (not read in this run)",
          "listed": false
        }
      ],
      "recycling": "USGS: in 2025 an estimated 1 million tons of secondary lead was produced, equal to 70% of apparent US consumption, nearly all recovered from old scrap, mostly lead-acid batteries.",
      "substitutes": [
        "USGS: the electronics industry has moved toward flat-panel displays that do not require lead shielding; steel and zinc are common substitutes for lead in wheel weights (no substitute for lead glass is named)."
      ],
      "source": "usgs-mcs2026-lead",
      "where": "World Mine Production and Reserves table, 2025e column (world total 4,500 thousand t, rounded; shares calculated by Space Mushroom against that total); Final 2025 critical list note in the introduction; Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "USGS Mineral Commodity Summaries 2026: Lead",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf",
      "year": 2026
    },
    {
      "title": "Trace Sciences Lead(II) oxide safety data sheet (CAS 1317-36-8)",
      "type": "sds",
      "url": "https://tracesciences.com/wp-content/uploads/2025/04/LeadII-oxide-SDS.pdf",
      "year": 2025
    },
    {
      "title": "NIST X-Ray Mass Attenuation Coefficients: Glass, Lead",
      "type": "database",
      "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/glass.html",
      "year": 2026
    },
    {
      "title": "NIST X-Ray Mass Attenuation Coefficients, Table 2 material constants",
      "type": "database",
      "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/tab2.html",
      "year": 2026
    },
    {
      "title": "SCHOTT Technical details of radiation shielding glasses",
      "type": "datasheet",
      "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
      "year": 2026
    },
    {
      "title": "SCHOTT Product variants of radiation shielding glasses",
      "type": "datasheet",
      "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/product-variants",
      "year": 2026
    },
    {
      "title": "Fathi, F. M., 2006. Mass Attenuation of Gamma Photons in Special Lead Glass that Can be Used in Radiation Shielding Windows",
      "type": "paper",
      "url": "https://jamh.uomosul.edu.iq/index.php/rsci/article/download/47397/47135/47440",
      "year": 2006
    }
  ],
  "gaps": [
    "No flight, vacuum, thermal-vacuum or space-radiation result for lead glass was found in this run; no space application was read.",
    "No crustal abundance figure for lead was opened in this run.",
    "The EU critical raw materials status of lead was not checked in this run.",
    "The NIST table has about 200 rows; only the energies listed in properties were read. The 0.662 MeV row is not printed (the nearest printed row, 0.6 MeV, is not used).",
    "The RS Pb-equivalent values for RS 253 to RS 520 are printed without a unit, so they are left out.",
    "The official current SCHOTT RS datasheet PDF was not opened (the search results point to 2013 flyers and regional pages with different figures); the values here come from the SCHOTT technical-details and product-variants pages only.",
    "A regional search snippet gave a different RS 520 refractive index from the technical-details page. That page was not opened, so the difference is not resolved.",
    "The NIST composition is an assumed example for X-ray tables, not a product specification, and it is not reconciled with SCHOTT's lead oxide contents, which are given as minimums and as synthesis figures.",
    "Chemical resistance to acids and alkalis, and ageing under heat, humidity or UV for finished lead glass, were not found in any source opened in this run.",
    "No service-temperature or transformation-temperature value for a lead glass product was read in this run.",
    "No GHS classification for finished lead glass was found; PubChem was not reachable (automated browser check), so the PbO SDS is the only hazard source.",
    "Manufacturing process (melting and casting of lead glass) was not read in a source in this run.",
    "Mass attenuation coefficients are for NIST's assumed composition only; no product-specific attenuation table at matching energies was found for RD 30 or RD 50.",
    "The meaning of the DIN ISO 719 hydrolytic classes (HGB 1 and HGB 3) was not read in full."
  ],
  "story": {
    "why": "Lead glass is a transparent material for shielding X-rays and gamma rays where a window or viewing panel is needed. NIST's assumed lead glass has a density of 6.220 g/cm3 and 75.19% lead by weight. SCHOTT's RD 50 has a minimum density of 5.05 g/cm3 and at least 65% lead oxide, and transmits 85% of visible light at 5.0 mm. The sources read here show the same trade: more lead gives more shielding and more density, and RD 50 keeps a view through the glass.",
    "uses": [
      {
        "where": "CT and PET facilities and analytical equipment (RD 50)",
        "line": "SCHOTT says RD 50 is supplied as stock sheets or custom panels with boreholes and cut-outs. It is suited to PET and CT scan facilities and to windows, doors and panoramic glazing for analytical equipment."
      },
      {
        "where": "Mammography (RD 30)",
        "line": "SCHOTT says RD 30 is developed for analogue and digital mammography, is available in large sizes, and can be bent or moulded."
      },
      {
        "where": "Nuclear energy and nuclear waste facilities (RS series)",
        "line": "SCHOTT says the RS glasses were developed for nuclear energy production and nuclear waste treatment, and are supplied as finished blocks, plates or custom castings for shielding window frames."
      }
    ],
    "can_do": [
      {
        "label": "Visible light",
        "line": "RD 50 transmits 85% of visible light at 5.0 mm thickness, and RD 30 transmits 90.5% at 6.0 mm, both per SCHOTT's technical data.",
        "benchmark": "light_transmittance",
        "scope": "material",
        "value": "85 %"
      },
      {
        "label": "Lead equivalent at 80 kV",
        "line": "RD 50 in a 5.0 to 7.0 mm thick sheet gives 1.5 mm Pb equivalence at 80 kV. RD 30 at 6.0 mm gives at least 0.5 mm Pb at 80 kV, per SCHOTT's lead-equivalent tables.",
        "benchmark": "lead_equivalent",
        "scope": "material",
        "value": "1.5 mm Pb"
      },
      {
        "label": "Gamma attenuation",
        "line": "RS 520 has a linear attenuation coefficient of 0.3 cm-1 at 1.25 MeV (the 60Co line), 0.5 cm-1 at 0.662 MeV (137Cs) and 3.54 cm-1 at 0.2 MeV, per SCHOTT's table.",
        "benchmark": "linear_attenuation_coefficient",
        "scope": "material",
        "value": "0.3 cm-1"
      },
      {
        "label": "Density",
        "line": "The RD 50 minimum density is 5.05 g/cm3 and the RS 520 minimum density is 5.18 g/cm3, both as printed by SCHOTT.",
        "benchmark": "density",
        "scope": "material",
        "value": "5.05 g/cm3"
      }
    ],
    "compare": "Lead glass is heavier than ordinary soda-lime glass, which Wikipedia describes as having a lower density. Among the SCHOTT products read here, RS 520 has the highest lead oxide content (71 wt% by synthesis) and the highest minimum density (5.18 g/cm3), and its linear attenuation at 1.25 MeV is 0.3 cm-1. RD 50 has a lower lead oxide content (at least 65%) and minimum density (5.05 g/cm3), and transmits 85% of visible light at 5.0 mm. RD 30 has the lowest minimum density in this group (at least 3.13 g/cm3) and is the product SCHOTT aims at mammography.",
    "compare_rows": [
      {
        "label": "Minimum density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Lead oxide content",
        "benchmark": "lead_oxide_content",
        "scope": "material"
      },
      {
        "label": "Visible light transmittance",
        "benchmark": "light_transmittance",
        "scope": "material"
      }
    ],
    "handling": [
      "The lead oxide powder is hazardous; the finished glass has no GHS classification found in this run. Keep dust down and collect broken pieces.",
      "Store the lead oxide locked up. Dispose of waste at an approved plant.",
      "For RS glasses, the application-limit table gives a discoloration total-dose limit of 1 × 10^8 Gy for RS 253 G18 and above 1 × 10^8 Gy for RS 323 G19, and no figure for RS 360 or RS 520.",
      "RD 30 is scratch-resistant and easier to clean than acrylic, according to SCHOTT."
    ],
    "good_for": [
      "Viewing windows in CT, PET and analytical facilities, where both shielding and a view through the glass are needed. RD 50 transmits 85% of visible light at 5.0 mm.",
      "Mammography panels, where SCHOTT gives a lead equivalent of at least 0.5 mm Pb at 6.0 mm for RD 30.",
      "Nuclear window frames with high total-dose tolerance, where the RS series is supplied as blocks, plates or castings."
    ],
    "watch_out": [
      "The lead oxide powder is hazardous. The finished glass was not classified in any source read.",
      "Lead glass is dense: RS 520 has a minimum density of 5.18 g/cm3, and RD 50 has a minimum of 5.05 g/cm3.",
      "Browning and induced discharge in RS glasses appear above fixed total-dose limits printed by SCHOTT. The table does not give a limit for every RS glass.",
      "No flight or space use was found in this run."
    ],
    "verdict": "The sources read support lead glass for transparent X-ray and gamma shielding in fixed installations such as CT, PET, analytical equipment and nuclear windows. The SCHOTT figures show the trade between lead content, density and visible transmission, and no space qualification was found.",
    "recipe": {
      "line": "Lead glass is a glass in which lead oxide, PbO, is a major ingredient; in ordinary glass the same position is held by calcium. NIST's assumed composition for Glass, Lead is 75.19% lead by weight, with oxygen, silicon, titanium and arsenic making up the rest.",
      "parts": [
        {
          "name": "Lead",
          "symbol": "Pb",
          "role": "Carries most of the mass of the glass, which gives it high density and strong absorption of X-rays and gamma rays."
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Bonds to lead and silicon to form the glass network."
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Forms the silica network that holds the glass together."
        },
        {
          "name": "Titanium",
          "symbol": "Ti",
          "role": "Minor constituent in NIST's assumed composition; its role is not described in the sources read."
        },
        {
          "name": "Arsenic",
          "symbol": "As",
          "role": "Minor constituent in NIST's assumed composition; its role is not described in the sources read."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The glass itself has no GHS classification found in this run. The lead oxide used to make it is classified as hazardous.",
        "points": [
          {
            "label": "The lead oxide",
            "line": "The Trace Sciences SDS for lead(II) oxide lists the signal word Danger with H360 (may damage fertility or the unborn child), H372 (organ damage through repeated exposure), H351 (suspected cancer hazard) and H410 (very toxic to aquatic life). That SDS is for the powder."
          },
          {
            "label": "Dust",
            "line": "The lead oxide SDS asks users to avoid breathing dust, fume or gas, and to collect spillage."
          }
        ],
        "level": 0,
        "verdict": "Hazard is in the lead oxide, not the glass sheet"
      },
      {
        "title": "In use",
        "lead": "These are the protection and handling limits printed by SCHOTT for its shielding glasses.",
        "points": [
          {
            "label": "Browning at high dose",
            "line": "SCHOTT lists discoloration limits of 1 × 10^8 Gy for RS 253 G18 and above 1 × 10^8 Gy for RS 323 G19. Cerium oxide doping is said to prevent browning in these two glasses."
          },
          {
            "label": "Induced discharge",
            "line": "For RS 253, RS 360 and RS 520 the table gives a total-dose limit for induced discharge of 1 × 10^3 Gy."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage",
            "line": "The PbO safety data sheet asks for the container to be stored locked up and for waste to go to an approved disposal plant."
          },
          {
            "label": "Glass properties",
            "line": "SCHOTT describes RD 30 as scratch-resistant, non-flammable and easier to clean than acrylic."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 19,
    "unreachable": 1,
    "caveats": 3,
    "note": "Drafted by an AI assistant on 2026-11-01 from pages fetched in this run: NIST attenuation and composition tables, SCHOTT technical and product pages, USGS 2026 lead chapter and a PbO safety data sheet. PubChem was not reachable."
  },
  "sources": {
    "nist-glass-lead": {
      "title": "X-Ray Mass Attenuation Coefficients: Glass, Lead (NIST)",
      "id": "NIST XCOM, Glass, Lead (ComTab/glass.html)",
      "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/glass.html",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NIST)"
    },
    "nist-table2": {
      "title": "X-Ray Mass Attenuation Coefficients, Table 2: Material constants and composition assumed in the present evaluations",
      "id": "NIST, Table 2 (tab2.html)",
      "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/tab2.html",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NIST)"
    },
    "schott-rs-rd": {
      "title": "SCHOTT Technical Details of Radiation Shielding Glasses (RD 30, RD 50 and RS series)",
      "id": "SCHOTT AG, radiation shielding glasses, technical details page",
      "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/technical-details",
      "year": 2026,
      "kind": "datasheet",
      "license": "manufacturer web page, cited not reproduced"
    },
    "schott-variants": {
      "title": "SCHOTT Product Variants of Radiation Shielding Glasses",
      "id": "SCHOTT AG, radiation shielding glasses, product variants page",
      "url": "https://www.schott.com/en-gb/products/radiation-shielding-glasses/product-variants",
      "year": 2026,
      "kind": "datasheet",
      "license": "manufacturer web page, cited not reproduced"
    },
    "usgs-mcs2026-lead": {
      "title": "Mineral Commodity Summaries 2026: Lead",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "trace-pbo-sds": {
      "title": "Safety Data Sheet: Lead(II) oxide (Trace Sciences International)",
      "id": "CAS 1317-36-8; EC 215-267-0",
      "url": "https://tracesciences.com/wp-content/uploads/2025/04/LeadII-oxide-SDS.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "wikipedia-lead-glass": {
      "title": "Lead glass (Wikipedia)",
      "id": "en.wikipedia.org/wiki/Lead_glass",
      "url": "https://en.wikipedia.org/wiki/Lead_glass",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    },
    "mosul-fathi-2006": {
      "title": "Mass Attenuation of Gamma Photons in Special Lead Glass that Can be Used in Radiation Shielding Windows",
      "id": "Raf. Jour. Sci., Vol. 17, No. 2 (Physics, Special Issue), pp. 6-12, 2006",
      "url": "https://jamh.uomosul.edu.iq/index.php/rsci/article/download/47397/47135/47440",
      "year": 2006,
      "kind": "paper",
      "license": "journal PDF, cited not reproduced"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/lead-glass/"
}