Cadmium Cd

spore: profile
id: cadmium
spore_version: 0.2
family: low-melting-metals-and-solders
name: Cadmium
abbreviation: Cd
role: battery electrode (nickel-cadmium cells) and corrosion-protective plating
category: metals
type: heavy-metals
summary: |
  Cadmium (Cd, atomic number 48) is a soft, silvery-white metal recovered as a by-product of zinc refining. Its main use is the negative electrode of nickel-cadmium (NiCd) batteries, and it is also electrodeposited on steel for corrosion protection and used in cadmium telluride (CdTe) thin-film solar panels. The metal melts at 321 °C and boils at 765 °C, has a density of 8.69 g/cm3 at 25 °C, and is very toxic: the supplier safety data sheet classifies it as carcinogenic (Category 1A), and PubChem's aggregated notifications list fatal inhalation toxicity (H330) for 92.2% of reports.
best_for: Corrosion-resistant electrodeposited coatings on steel, where salt-fog protection was the reason it was chosen (NASA tested it against zinc-nickel)
weakest_at: 'Health: fatal if inhaled and suspected of causing cancer, and USGS reports substitutes for it in batteries, plating and pigments. Also weak in salt fog once a coating is unsealed (corrosion after 240 hours in NASA''s test)'
identity:
  formula: Cd (element, atomic number 48, CAS 7440-43-9); a soft metal with a hexagonal close-packed crystal structure
  cas: 7440-43-9
  source: pubchem-cd
  where: PubChem record for cadmium (CID 23973; molecular weight 112.41 g/mol, computed by PubChem). CAS 7440-43-9 is printed in section 1 of the safety data sheet (sds-durham). Symbol Cd, atomic number 48, and discovery in 1817 are from the Wikipedia article (wiki-cadmium).
tags:
  environments: []
  stresses: []
  applications:
    - batteries
    - solar-arrays
    - structures
properties:
  - benchmark: density
    label: Density of cadmium metal
    value: 8.69
    unit: g/cm3
    scope: material
    conditions:
      temperature: 25 °C
      basis: CRC Handbook value quoted in the PubChem record
    method: Experimental property value listed in PubChem, citing the CRC Handbook (Lide, 88th edition)
    status: ground
    source: pubchem-cd
    where: Experimental Properties, Density entry
  - benchmark: melting_point
    value: 321
    unit: °C
    scope: material
    conditions:
      basis: metal as supplied (Melting Point/Range)
    method: Physical and chemical properties table of the supplier safety data sheet
    status: ground
    source: sds-durham
    where: Section 9, Physical and chemical properties, Melting Point/Range row
  - benchmark: boiling_point
    value: 765
    unit: °C
    scope: material
    conditions:
      pressure: 760 mmHg
    method: Physical and chemical properties table of the supplier safety data sheet
    status: ground
    note: PubChem quotes 767 °C from the CRC Handbook; the safety data sheet prints 765 °C, and this profile uses the safety data sheet value.
    source: sds-durham
    where: Section 9, Physical and chemical properties, Boiling Point/Range row
  - benchmark: heat_of_vaporization
    label: Heat of vaporization at the boiling point
    value: 99.87
    unit: kJ/mol
    scope: material
    conditions:
      temperature: 767 °C (boiling point)
    method: Value listed in PubChem, citing the CRC Handbook
    status: ground
    source: pubchem-cd
    where: Experimental Properties, Heat of Vaporization entry
  - benchmark: vapor_pressure
    label: Vapour pressure at 381 °C
    value: 100
    unit: Pa
    scope: material
    conditions:
      temperature: 381 °C
      note: PubChem lists 1 Pa at 257 °C (sublimes) and 1 kPa at 472 °C from the same table
    method: Vapour pressure table listed in PubChem, citing the CRC Handbook
    status: ground
    source: pubchem-cd
    where: Experimental Properties, Vapor Pressure entry
  - benchmark: thermal_conductivity
    value: 97
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: not stated on the page
    method: Physical data table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Heat and conduction, Thermal conductivity row
  - benchmark: cte
    label: Coefficient of linear thermal expansion
    value: 30.8
    unit: ppm/K
    scope: material
    conditions:
      temperature: not stated on the page
    method: Printed as 30.8 × 10-6 K-1 on the WebElements page; 10-6 K-1 is the same unit as ppm/K, so the number is unchanged
    status: ground
    source: webelements-cd
    where: Heat and conduction, coefficient of linear thermal expansion row
  - benchmark: elastic_modulus
    label: Young's modulus
    value: 50
    unit: GPa
    scope: material
    conditions:
      temperature: not stated on the page
    method: Elastic properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Elastic properties, Young's modulus row
  - benchmark: shear_modulus
    label: Rigidity (shear) modulus
    value: 19
    unit: GPa
    scope: material
    conditions:
      temperature: not stated on the page
    method: Elastic properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Elastic properties, Rigidity modulus row
  - benchmark: bulk_modulus
    value: 42
    unit: GPa
    scope: material
    conditions:
      temperature: not stated on the page
    method: Elastic properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Elastic properties, Bulk modulus row
  - benchmark: poissons_ratio
    value: 0.3
    unit: '-'
    scope: material
    conditions:
      temperature: not stated on the page
    method: Elastic properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Elastic properties, Poisson's ratio row
  - benchmark: brinell_hardness
    label: Brinell hardness
    value: 203
    unit: MN/m2
    scope: material
    conditions:
      state: not stated on the page
    method: Printed as 203 MN m -2 on the WebElements page; MN/m2 is the same unit as MPa
    status: ground
    source: webelements-cd
    where: Hardnesses, Brinell hardness row
  - benchmark: mineral_hardness
    label: Mohs hardness
    value: 2
    unit: '-'
    scope: material
    conditions:
      scale: Mohs mineral hardness
    method: Hardnesses table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Hardnesses, Mineral hardness row
  - benchmark: reflectivity
    value: 67
    unit: '%'
    scope: material
    conditions:
      wavelength: not stated on the page
    method: Optical properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Optical properties, Reflectivity row
  - benchmark: molar_volume
    value: 13
    unit: cm3/mol
    scope: material
    conditions:
      temperature: not stated on the page
    method: Density properties table of the WebElements element page
    status: ground
    source: webelements-cd
    where: Density properties, Molar volume row
  - benchmark: cell_specific_energy
    label: Measured energy density of experimental NiCd cells (negative-limited, non-gassing)
    value: 10
    value_high: 11
    bound: range
    unit: Wh/lb
    scope: cell
    conditions:
      cell: about 25 Ah negative-limited nickel-cadmium experimental cells
      electrode: electrodeposited cadmium on a silver screen (the best of four cadmium electrode types tested)
      operation: gas-free operation
    method: Measured energy densities reported in the Gould Inc. final report for JPL (1972)
    status: ground
    note: Laboratory cells from a 1972 development report, not a commercial cell; energy density is quoted in the units the report prints.
    source: ntrs-1972
    where: Summary (abstract), paragraph beginning 'This report describes work conducted at Gould Inc.'
corrosion:
  - environment: Moist air at room temperature
    headline: Cadmium tarnishes in moist air and slowly oxidizes to cadmium oxide.
    effect: PubChem's physical description of the metal says it tarnishes on exposure to moist air. Merck's entry, quoted in PubChem, says moist air slowly oxidizes it to cadmium oxide. No rate or humidity figure is given in these entries.
    rating: low
    conditions:
      basis: qualitative descriptions in two reference entries; no exposure time or humidity is given
    source: pubchem-cd
    where: Physical Description and Stability/Shelf Life entries
  - environment: Salt fog, 5 percent salt solution at 35 °C, for 96 to 240 hours
    headline: Electrodeposited cadmium on steel showed no corrosion after 96 hours, but stains appeared, and after 240 hours the unsealed coating had corroded.
    effect: NASA Marshall tested cadmium on 4130 steel against electrodeposited zinc-nickel. After 96 hours the cadmium had stains but no corrosion. After 240 hours the cadmium without a dichromate seal showed corrosion, and the sealed sample showed severe staining but no corrosion. The report credits cadmium with the best combination of salt-water corrosion resistance, low friction and low electrical contact resistance among the coatings it reviewed.
    rating: moderate
    conditions:
      substrate: 4130 steel with electrodeposited cadmium, per Federal Specification QQ-P-416
      seal: with and without dichromate seal
      temperature: 35 ± 2 °C
    source: ntrs-1991
    where: Experimental Procedures and Results, Figures 4a and 4b
risks:
  hazards:
    - text: 'PubChem''s aggregated notifications to the ECHA Classification and Labelling Inventory (855 company reports): H330 fatal if inhaled (92.2% of reports), H341 suspected of causing genetic defects (92.2%), H350 may cause cancer (92.2%), H372 causes damage to organs through prolonged or repeated exposure (92.2%), and H400 and H410 very toxic to aquatic life.'
      ghs:
        - H330
        - H341
        - H350
        - H361fd
        - H372
        - H400
        - H410
      source: pubchem-cd
      where: GHS Classification, ECHA C and L Notifications Summary
    - text: 'Supplier safety data sheet (Revision 3, 17 January 2018): carcinogenicity Category 1A. Some reports also give pyrophoric solid (H250, catches fire spontaneously if exposed to air) for particular forms, so the form you handle matters.'
      ghs: []
      source: sds-durham
      where: Section 2, Hazard(s) identification, and the Carcinogenicity line
    - text: 'Exposure limits in the safety data sheet, for cadmium: ACGIH TLV 0.01 mg/m3 (TWA), OSHA PEL ceiling 0.3 mg/m3, NIOSH IDLH 9 mg/m3.'
      ghs: []
      source: sds-durham
      where: Section 8, Exposure controls, limits table
  failure_risks:
    - mode: Inhalation of cadmium dust or fume
      trigger: Heating, cutting or grinding cadmium, or handling its powder, which forms dust
      consequence: Fatal if inhaled (H330), according to the aggregated classification in PubChem; the safety data sheet gives an LC50 of 25 mg/m3 (rat, 30 minutes).
      severity: high
      source: pubchem-cd
      where: GHS Hazard Statements (aggregated); the rat LC50 is in Section 11 of sds-durham
    - mode: Embrittlement of high-strength steel by a cadmium coating
      trigger: Electrodeposited cadmium on high-strength steel parts
      consequence: The NASA report lists solid and liquid metal embrittlement of high-strength steels as a disadvantage that drove the search for alternatives to cadmium plating.
      severity: moderate
      source: ntrs-1991
      where: Introduction
  side_effects:
    - text: Very toxic to aquatic life with long-lasting effects (H410) in the aggregated PubChem classification.
      affects: Waterways and aquatic organisms near discharges
      source: pubchem-cd
      where: GHS Hazard Statements (aggregated), H400 and H410
  handling:
    - text: 'Safety data sheet, Section 7: avoid dust formation, work under a chemical fume hood, do not breathe dust, and keep containers tightly closed in a dry, cool, well-ventilated place under an inert atmosphere.'
      source: sds-durham
      where: Section 7, Handling and storage
    - text: 'Safety data sheet, Section 10: keep away from strong oxidizing agents, strong acids and sulfur oxides; the metal is moisture and air sensitive.'
      source: sds-durham
      where: Section 10, Stability and reactivity
  mitigations:
    - text: NASA evaluated electrodeposited zinc-nickel as a replacement for cadmium plating in aerospace use. The report gives embrittlement of high-strength steels and occupational health concerns as the reasons for seeking an alternative.
      source: ntrs-1991
      where: Introduction and Experimental Procedures
uses:
  - application: batteries
    device: Nickel-cadmium (NiCd) batteries
    example: USGS reports that cadmium metal and compounds are mainly consumed for NiCd batteries. It also reports a shift from NiCd toward lithium-based batteries in the consumer market, while industrial NiCd batteries remain favoured for their reliability and longevity.
    source: usgs-mcs2026-cadmium
    where: Domestic Production and Use, first paragraph
  - application: batteries
    device: Experimental negative-limited, non-gassing nickel-cadmium cells (development, not flight hardware)
    example: Gould Inc. built experimental cells of about 25 Ah for JPL in 1972; they operated gas-free with measured energy densities of 10-11 Wh/lb, and some small cells were cycled for over 200 cycles.
    source: ntrs-1972
    where: Summary (abstract)
  - application: solar-arrays
    device: Cadmium telluride (CdTe) thin-film solar panels
    example: USGS reports that CdTe thin-film panels are increasingly used in the solar industry, and that the leading domestic manufacturer expected to reach about 14 gigawatts per year of capacity once fully ramped up in 2026. These sources do not describe space-flown arrays.
    source: usgs-mcs2026-cadmium
    where: Events, Trends, and Issues
  - application: structures
    device: Electrodeposited cadmium coatings on aerospace steel parts
    example: NASA tested electrodeposited cadmium on 4130 steel samples for aerospace corrosion protection, against electrodeposited zinc-nickel, in a 5 percent salt fog for 96 to 240 hours.
    source: ntrs-1991
    where: Experimental Procedures, Phase I
supply:
  - subject: Cadmium
    producers:
      - country: China
        share_percent: 41.3
        year: 2025
      - country: Korea Republic of
        share_percent: 18.7
        year: 2025
      - country: Japan
        share_percent: 5.7
        year: 2025
      - country: Canada
        share_percent: 5.7
        year: 2025
      - country: Kazakhstan
        share_percent: 4.8
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (60 minerals; cadmium is not among them)
        listed: false
      - list: EU critical raw materials list (34 materials under Regulation (EU) 2024/1252; cadmium is not among them)
        listed: false
    recycling: 'USGS: secondary cadmium is mainly recovered from spent consumer and industrial NiCd batteries; other scrap includes copper-cadmium alloy scrap, electric-arc furnace dust and CdTe solar panels. One company in Ohio recovered cadmium metal from NiCd battery recycling.'
    substitutes:
      - 'USGS: lithium-ion and other chemistries can replace NiCd batteries in many applications; zinc-nickel coatings can replace cadmium in many plating applications, except where surface characteristics are critical (for example aircraft fasteners); cerium sulfide replaces cadmium pigments; barium stabilizers replace barium-cadmium stabilizers in PVC.'
    source: usgs-mcs2026-cadmium
    where: 'World Refinery Production table, 2025e (world total 23,000 t; shares calculated by Space Mushroom from the country values of 9,500, 4,300, 1,300, 1,300 and 1,100 t); Recycling; Substitutes. Cadmium is produced mainly as a by-product of zinc refining (USGS footnote 1). Critical lists: USGS and European Commission pages (see sources).'
media: []
documents:
  - title: Cadmium safety data sheet, Revision 3 (17 January 2018), supplier document
    type: sds
    url: https://www.durhamtech.edu/sites/default/files/safety_data_sheets/Chemistry-and-Biology/Cadmium%20%7BCd%7D%20cas7440-43-9%20SDS.pdf
    year: 2018
  - title: 'PubChem: Cadmium (CID 23973), GHS classification and experimental properties'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Cadmium
    year: 2026
  - title: 'WebElements: Cadmium, physics and properties'
    type: database
    url: https://www.webelements.com/cadmium/physics.html
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Cadmium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cadmium.pdf
    year: 2026
  - title: 'NASA TM-103551: Electro Deposited Zinc-Nickel as an Alternative to Cadmium Plating for Aerospace Application (1991)'
    type: report
    url: https://ntrs.nasa.gov/citations/19910022903
    year: 1991
  - title: Non-Gassing Nickel-Cadmium Battery Electrodes and Cells, Gould Inc. final report 712-122-4 for JPL (1972)
    type: report
    url: https://ntrs.nasa.gov/citations/19720025406
    year: 1972
gaps:
  - No flight, vacuum, radiation or thermal-vacuum result for cadmium found in this run. The space links are a 1972 ground development of NiCd cells and a 1991 salt-fog plating test; no space flight use is shown.
  - No crustal abundance figure for cadmium was read; the USGS summary gives reserves only as 'not available' and a typical zinc-ore content of about 0.03% (not used).
  - No specific heat, electrical resistivity or tensile strength value was verified from a page read in this run. The WebElements page prints electrical resistivity as 7 x 10-8 ohm m, which the verification script cannot match, so it was left out.
  - 'These benchmark names are not in property-canon.yaml and are used as snake_case names: brinell_hardness, mineral_hardness, reflectivity, molar_volume, heat_of_vaporization, cell_specific_energy and vapor_pressure.'
  - No UNS, EN or other grade designation for cadmium metal was read in a source for this run, so identity.designations is empty.
  - The ATSDR toxicological profile and the NIOSH Pocket Guide could not be fetched in this run; exposure limits come from the safety data sheet only. Its OSHA line lists several values, so only ACGIH, OSHA ceiling and NIOSH IDLH are quoted.
  - The neutron-poison use (control rods in fission reactors) appears in Wikipedia only and no primary source was read, so it is not listed under uses.
  - Critical-list status was read from the USGS and European Commission pages through a summarising fetch, not from a full list download; cadmium was not found on either list.
  - No image or media file was added for cadmium in this run.
sources:
  usgs-mcs2026-cadmium:
    title: Mineral Commodity Summaries 2026, Cadmium
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cadmium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS, final list of 60 minerals)
    id: Final 2025 List of Critical Minerals, November 2025
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  ec-crm:
    title: Critical raw materials (European Commission, list of 34 critical raw materials under Regulation (EU) 2024/1252)
    id: Regulation (EU) 2024/1252
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2024
    kind: web
    license: European Commission web page
  pubchem-cd:
    title: PubChem compound record, Cadmium (CID 23973), experimental properties and GHS classification
    id: CID 23973; CAS 7440-43-9
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23973/JSON
    year: 2026
    kind: database
    license: public domain (NCBI)
  webelements-cd:
    title: 'WebElements: Cadmium, physics (density, elastic, thermal and hardness properties)'
    id: WebElements, cadmium page
    url: https://www.webelements.com/cadmium/physics.html
    year: 2026
    kind: database
    license: WebElements, cited not reproduced
  sds-durham:
    title: Cadmium safety data sheet, Revision 3 (Durham Technical Community College copy)
    id: Revision date 17 January 2018; CAS 7440-43-9
    url: https://www.durhamtech.edu/sites/default/files/safety_data_sheets/Chemistry-and-Biology/Cadmium%20%7BCd%7D%20cas7440-43-9%20SDS.pdf
    year: 2018
    kind: datasheet
    license: supplier document, linked not reproduced
  ntrs-1972:
    title: Non-Gassing Nickel-Cadmium Battery Electrodes and Cells (Gould Inc., report 712-122-4, JPL contract 953184)
    id: NASA NTRS 19720025406
    url: https://ntrs.nasa.gov/citations/19720025406
    year: 1972
    kind: report
    license: public domain (NASA)
  ntrs-1991:
    title: 'NASA TM-103551: Electro Deposited Zinc-Nickel as an Alternative to Cadmium Plating for Aerospace Application (V. C. McMillan)'
    id: NASA TM-103551, NTRS 19910022903
    url: https://ntrs.nasa.gov/citations/19910022903
    year: 1991
    kind: report
    license: public domain (NASA)
  wiki-cadmium:
    title: Cadmium, Wikipedia (used for symbol, atomic number and discovery year only)
    id: en.wikipedia.org/wiki/Cadmium
    url: https://en.wikipedia.org/wiki/Cadmium
    year: 2026
    kind: web
    license: CC BY-SA 4.0
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 16
  unreachable: 2
  caveats: 2
  note: Written by an AI assistant on 2026-10-26 from pages read in this run. Values come from the PubChem record, the WebElements page, the supplier SDS, the USGS summary and two NASA reports. ATSDR and NIOSH pages could not be fetched.
story:
  recipe:
    line: Cadmium is a single element, not an alloy. It is produced mainly as a by-product of zinc refining, and it is used as the metal itself (electrode or coating) or as the cadmium part of a compound such as CdTe.
    parts:
      - name: Cadmium
        symbol: Cd
        atoms: 1
        atomic_weight: 112.41
        role: The whole material. In a NiCd cell it is the negative electrode; as a coating it sacrificially protects steel in salt fog.
  risk_groups:
    - title: For people
      level: 0
      verdict: Classified as carcinogenic and fatal if inhaled
      lead: Cadmium is a toxic metal. The safety data sheet classifies it as carcinogenic (Category 1A), and the aggregated PubChem classification lists fatal inhalation toxicity.
      points:
        - label: Dust and fume
          line: Dust and fume are the main route of harm. The safety data sheet asks for work under a fume hood and says to avoid dust formation.
        - label: Exposure limits
          line: The safety data sheet lists an ACGIH TLV of 0.01 mg/m3 (TWA), an OSHA ceiling of 0.3 mg/m3 and a NIOSH IDLH of 9 mg/m3.
        - label: Other effects
          line: PubChem's aggregated classification also lists suspected genetic defects (H341), possible harm to fertility or an unborn child (H361fd), and organ damage from repeated exposure (H372).
    - title: In the environment
      lead: The aggregated classification also marks cadmium as very toxic to aquatic life with long-lasting effects.
      points:
        - label: Water
          line: H400 and H410 apply to most notifications, so discharges and waste need to be controlled.
    - title: Handling and storage
      points:
        - label: Storage
          line: Keep containers tightly closed in a dry, cool, well-ventilated place, under an inert atmosphere, away from strong oxidizing agents and strong acids.
        - label: Air and moisture
          line: The safety data sheet calls the metal moisture and air sensitive, and tarnishes in moist air.
  why: 'Cadmium is chosen for three things. Its electrode chemistry gives long-lived, reliable batteries (NiCd). Its electrodeposited coating protects steel against salt water, and it keeps a low friction and low electrical contact resistance. And its telluride is a thin-film solar absorber. Each of these uses is now under pressure: the USGS reports that lithium-based batteries are replacing NiCd in consumer products, that zinc-nickel can replace cadmium plating in many applications, and that CdTe competes with silicon panels. The health classification is the main reason for the change.'
  uses:
    - where: Batteries
      line: USGS reports that cadmium metal and compounds are mainly consumed for nickel-cadmium batteries. Industrial NiCd batteries are still favoured for their reliability and longevity.
    - where: Thin-film solar panels
      line: USGS reports that CdTe thin-film panels are increasingly used in the solar industry. These sources do not describe space-flown arrays.
    - where: Aerospace coatings
      line: NASA Marshall tested electrodeposited cadmium on steel against zinc-nickel in salt fog. The report describes cadmium as a coating chosen for its corrosion resistance, low friction and low electrical contact resistance.
  can_do:
    - label: Energy density in a NiCd test
      benchmark: cell_specific_energy
      value: 10 to 11 Wh/lb
      line: Gould Inc. measured energy densities of 10 to 11 Wh/lb for about 25 Ah experimental nickel-cadmium cells that ran gas-free, in a 1972 development report.
    - label: Melting and boiling
      benchmark: melting_point
      value: 321 °C
      line: Cadmium melts at 321 °C and boils at 765 °C at standard pressure, according to the supplier safety data sheet. PubChem quotes 767 °C for the boiling point from the CRC Handbook.
    - label: Thermal conduction
      benchmark: thermal_conductivity
      value: 97 W/(m·K)
      line: WebElements lists a thermal conductivity of 97 W/(m·K) and a coefficient of linear thermal expansion of 30.8 ppm/K, without a temperature.
    - label: Stiffness and hardness
      benchmark: elastic_modulus
      value: 50 GPa
      line: WebElements lists a Young's modulus of 50 GPa and a Brinell hardness of 203 MN/m2 for the metal.
  compare: Cadmium is a soft metal that melts at 321 °C and has a density of 8.69 g/cm3. Its two main advantages were the NiCd electrode and the electrodeposited coating, and USGS reports substitutes for both. The table compares its melting point, density and thermal conductivity with the other metals in the collection.
  compare_rows:
    - label: Melting point
      benchmark: melting_point
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
  handling:
    - Cadmium is classed as carcinogenic and fatal if inhaled. Work under a fume hood and avoid dust.
    - Keep containers closed, dry and under an inert atmosphere, away from strong oxidizing agents and strong acids.
    - In NASA's salt-fog test, zinc-nickel was a corrosion-inhibiting alternative to cadmium on the same steel, with dichromate sealing giving the best result.
  good_for:
    - Corrosion protection of steel in salt fog. NASA found no corrosion on cadmium after 96 hours and corrosion only on the unsealed sample after 240 hours.
    - Nickel-cadmium cells with long life and reliable operation, as the USGS notes for industrial batteries.
  watch_out:
    - Fatal if inhaled and classed as carcinogenic; it is being replaced for this reason.
    - Once a coating is unsealed, corrosion appears within 240 hours of salt fog in the NASA test.
    - Embrittlement of high-strength steel is a documented disadvantage of cadmium plating.
  verdict: Cadmium still has real uses in NiCd batteries and CdTe panels, and its salt-fog protection is well documented. The toxicity classification means the metal is being replaced in most new designs, and this profile should be read as a record of what it did rather than a recommendation to use it.