spore: profile
id: antimonial-lead
spore_version: 0.2
family: low-melting-metals-and-solders
name: Antimonial lead
abbreviation: Pb-Sb
role: hard lead alloy (battery grids, radiation-shielding and ammunition uses)
category: metals
type: heavy-metals
summary: |
  Antimonial lead is lead alloyed with antimony, in this profile's scope 1 to 12 wt% Sb. Antimony hardens lead and improves castability, which is why lead-antimony alloys have been the usual grid metal for lead-acid batteries. The 2026 grid study says automotive grid alloys are produced only up to 3.5 wt% Sb, because antimony dissolves from the positive grid and deposits on the negative plate, raising gassing, water loss and self-discharge. USGS reports that antimonial lead and ammunition took 40% of US antimony use in 2025.
best_for: 'Lead-acid battery grids that need strength and good castability from a small antimony addition, and a recycling chain that already exists (USGS: secondary antimony comes from spent lead-acid batteries)'
weakest_at: Antimony leaches out of the positive grid, which raises gassing, water loss and self-discharge; lead is a reproductive toxicant with no known safe blood lead level (WHO), which limits handling and disposal
identity:
  formula: 'Pb-Sb alloy: lead with 1 to 12 wt% antimony; the grid alloys in the 2026 study are Pb-3.5 wt% Sb with arsenic or tin additions'
  source: usgs-mcs2026-antimony
  where: Domestic Production and Use paragraph (antimonial lead recovered from spent lead-acid batteries)
tags:
  environments: []
  stresses: []
  applications:
    - batteries
properties:
  - benchmark: density
    label: Density of antimony (element, for comparison)
    value: 6.68
    unit: g/cm3
    scope: material
    conditions:
      form: elemental antimony, 20 degC as printed
      basis: pure antimony, not the lead-antimony alloy
    method: Value printed in the PubChem record for antimony (CID 5354495)
    status: ground
    note: The record also prints 6.7, 6.69 and 6.684 g/cm3 in other entries. The density of the lead-antimony alloy itself was not found in a checked source.
    source: pubchem-sb
    where: Chemical and Physical Properties, Experimental Properties, Density (entry 6.68 g/cu cm at 20 C)
  - benchmark: melting_point
    label: Melting point of antimony (element, for comparison)
    value: 630.028
    unit: degC
    scope: material
    conditions:
      form: elemental antimony, gray form as printed in the record
      basis: pure antimony, not the alloy
    method: Value printed in the PubChem record for antimony (CID 5354495)
    status: ground
    note: The record also prints 630 degC and 630.628 degC in other entries. The solidus and liquidus of Pb-Sb alloys were not found in a checked source.
    source: pubchem-sb
    where: Chemical and Physical Properties, Experimental Properties, Melting Point (entry 630.028 degC, gray antimony)
  - benchmark: mass_atten_100keV
    label: Mass attenuation coefficient at 100 keV, lead (element)
    value: 5.549
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.1 MeV
      medium: elemental lead, Z = 82
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    note: 'Pure lead is the upper reference: antimony adds much less attenuation per gram (see the antimony row). The energy is just above the lead K edge.'
    source: nist-xray-z82
    where: Table 3, Lead (Z = 82), row 1.00000E-01 MeV, mu/rho column
  - benchmark: mass_atten_100keV
    label: Mass attenuation coefficient at 100 keV, antimony (element)
    value: 1.758
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.1 MeV
      medium: elemental antimony, Z = 51
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    source: nist-xray-z51
    where: Table 3, Antimony (Z = 51), row 1.00000E-01 MeV, mu/rho column
  - benchmark: mass_atten_60keV
    label: Mass attenuation coefficient at 60 keV, lead (element)
    value: 5.021
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.06 MeV
      medium: elemental lead, Z = 82
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    source: nist-xray-z82
    where: Table 3, Lead (Z = 82), row 6.00000E-02 MeV, mu/rho column
  - benchmark: mass_atten_60keV
    label: Mass attenuation coefficient at 60 keV, antimony (element)
    value: 6.879
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.06 MeV
      medium: elemental antimony, Z = 51
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    source: nist-xray-z51
    where: Table 3, Antimony (Z = 51), row 6.00000E-02 MeV, mu/rho column
  - benchmark: mass_atten_80keV
    label: Mass attenuation coefficient at 80 keV, lead (element)
    value: 2.419
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.08 MeV
      medium: elemental lead, Z = 82
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    note: 80 keV is just below the lead K edge at 88 keV, so the coefficient is lower here than at 100 keV.
    source: nist-xray-z82
    where: Table 3, Lead (Z = 82), row 8.00000E-02 MeV, mu/rho column
  - benchmark: mass_atten_80keV
    label: Mass attenuation coefficient at 80 keV, antimony (element)
    value: 3.176
    unit: cm2/g
    scope: material
    conditions:
      photon_energy: 0.08 MeV
      medium: elemental antimony, Z = 51
      quantity: mu/rho total, narrow beam
    method: NIST XCOM-based tabulation (theory and data, not a measurement on an alloy sample)
    status: calculated
    source: nist-xray-z51
    where: Table 3, Antimony (Z = 51), row 8.00000E-02 MeV, mu/rho column
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, Pb-3.5Sb-0.23As grid alloy, as cast
    value: 34.8
    value_high: 38.9
    bound: range
    unit: MPa
    scope: material
    conditions:
      alloy: Pb-3.5 wt% Sb-0.23 wt% As
      form: as-cast grid alloy, room temperature
      cooling: casting mold preheated between 50 and 170 degC
      test: TIRAtest 2300 at a crosshead speed of 10 mm/min
    method: Room-temperature tensile test as reported in the paper; the range runs from the low to the high mold preheat temperature
    status: ground
    note: Strength falls as mold preheat rises (decrease of 11.8 %). This is a research grid alloy with 3.5 wt% Sb, not the full 1 to 12 wt% range.
    source: dzenzerskiy2026
    where: Results, text and Fig. 2a (ultimate tensile strength of Pb-3.5Sb-0.23As)
  - benchmark: elongation
    label: Elongation, Pb-3.5Sb-0.23As grid alloy, as cast
    value: 7.2
    value_high: 8.2
    bound: range
    unit: '%'
    scope: material
    conditions:
      alloy: Pb-3.5 wt% Sb-0.23 wt% As
      form: as-cast grid alloy, room temperature
      cooling: casting mold preheated between 50 and 170 degC
      test: TIRAtest 2300 at a crosshead speed of 10 mm/min
    method: Room-temperature tensile test as reported in the paper
    status: ground
    note: Elongation falls with mold preheat (decrease of 13.9 %), so the alloy becomes more brittle as the mold gets hotter.
    source: dzenzerskiy2026
    where: Results, text and Fig. 2b (elongation of Pb-3.5Sb-0.23As)
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, Pb-3.5Sb-0.5Sn-0.16As grid alloy, as cast
    value: 38.9
    value_high: 40
    bound: range
    unit: MPa
    scope: material
    conditions:
      alloy: Pb-3.5 wt% Sb-0.5 wt% Sn-0.16 wt% As
      form: as-cast grid alloy, room temperature
      cooling: casting mold preheated between 75 and 165 degC for this alloy
      test: TIRAtest 2300 at a crosshead speed of 10 mm/min
    method: Room-temperature tensile test as reported in the paper
    status: ground
    note: Tin in place of part of the arsenic lowers strength by only 2.8 % and gives more stable properties across mold temperatures than the arsenic-only alloy.
    source: dzenzerskiy2026
    where: Results, text and Fig. 3a (ultimate tensile strength of Pb-3.5Sb-0.5Sn-0.16As)
  - benchmark: elongation
    label: Elongation, Pb-3.5Sb-0.5Sn-0.16As grid alloy, as cast
    value: 8.1
    value_high: 8.3
    bound: range
    unit: '%'
    scope: material
    conditions:
      alloy: Pb-3.5 wt% Sb-0.5 wt% Sn-0.16 wt% As
      form: as-cast grid alloy, room temperature
      cooling: casting mold preheated between 75 and 165 degC for this alloy
      test: TIRAtest 2300 at a crosshead speed of 10 mm/min
    method: Room-temperature tensile test as reported in the paper
    status: ground
    note: Elongation rises slightly (2.4 %) with mold preheat for this alloy, the opposite trend to the arsenic-only alloy.
    source: dzenzerskiy2026
    where: Results, text and Fig. 3b (elongation of Pb-3.5Sb-0.5Sn-0.16As)
corrosion:
  - environment: Positive grid in sulfuric acid electrolyte of a lead-acid battery
    headline: Antimony leaves the positive grid and deposits on the negative plate, which the paper links to high water loss and self-discharge.
    effect: The 2026 study says high-antimony lead alloys increase battery gassing during charging, leading to high water loss, and that the high discharge rate and short life of high-antimony batteries come from antimony dissolving from one electrode and depositing on the other. It also says high-antimony alloys are prone to sulfation and should not be left at low states of charge.
    rating: moderate
    conditions:
      basis: qualitative statements in the introduction of a study of grid tensile properties; no corrosion rate, electrolyte concentration or test duration is given in the text read
      antimony_range: high-antimony versus medium (3.0 to 4.0 wt%) alloys
    source: dzenzerskiy2026
    where: Introduction, paragraphs 1 and 2 (refs 11 to 14 as cited)
  - environment: Anodic dissolution of antimony in a lead-antimony grid
    headline: Grain refinement changes how the grid corrodes, which the 1988 Korean study explains through anodic dissolution of antimony.
    effect: The abstract of the 1988 study says grain size depends on antimony content, can be reduced by adding selenium, and that the grain refining affected corrosion in terms of anodic dissolution of antimony. The abstract gives no corrosion rate, electrolyte or test time, so the rating is unknown.
    rating: unknown
    conditions:
      basis: abstract only (the full text was not opened)
      alloy: low-antimony lead alloys
    source: kim1988
    where: Abstract, Structure and Corrosion Behavior of Low Antimony-Lead Alloys (1988)
risks:
  hazards:
    - text: 'PubChem record for elemental antimony (CID 5354495), aggregated from ECHA C&L notifications: signal word Danger; H301 (18.2%), H302 (23.4%) and H332 (26.9%) of the notifying reports; 140 of 748 reports say the substance does not meet GHS criteria.'
      ghs:
        - H301
        - H302
        - H332
      source: pubchem-sb
      where: Safety and Hazards, Hazards Identification, GHS Classification
    - text: 'PubChem record for lead (CID 5352425), aggregated from ECHA C&L notifications: signal word Danger; H360 may damage fertility or the unborn child (84.4%), H362 may cause harm to breast-fed children (44.3%), H372 causes organ damage through prolonged or repeated exposure (50.5%), H373 (34.4%), H302 (36.2%) and H332 (38.4%). Notified classifications vary with impurities and additives, and 127 of 2477 reports say the substance does not meet GHS criteria.'
      ghs:
        - H360
        - H362
        - H372
        - H373
        - H302
        - H332
      source: pubchem-lead
      where: Safety and Hazards, Hazards Identification, GHS Classification (ECHA C&L Notifications Summary)
    - text: 'WHO: there is no known safe blood lead concentration. Young children may absorb up to 4 to 5 times as much lead as adults.'
      ghs: []
      source: who-lead
      where: Key facts; Health effects in children
  failure_risks:
    - mode: Sulfation, gassing and water loss in high-antimony grids
      trigger: Grid antimony above the automotive limit of 3.5 wt%, or long standing at low state of charge
      consequence: More gassing on charge, high water loss that needs topping up, high self-discharge and a shorter battery life. The paper ties these to antimony moving from one electrode to the other.
      severity: moderate
      source: dzenzerskiy2026
      where: Introduction, paragraphs 1 and 2
    - mode: Hot cracking when antimony is reduced in a cast grid
      trigger: Lowering the antimony content of a cast Pb-Sb grid without other additions
      consequence: Solidification in a coarse dendritic structure gives cracks along grain boundaries. The paper names this as the main casting difficulty, and says tin additions improve castability.
      severity: moderate
      source: dzenzerskiy2026
      where: Introduction, paragraph 4
  side_effects:
    - text: Antimony that dissolves from the positive grid deposits on the negative plate and drives self-discharge and water loss.
      affects: Negative plate and battery water balance
      source: dzenzerskiy2026
      where: Introduction, paragraph 2
    - text: Brittle arsenic-containing phases form at grain boundaries in Pb-3.5Sb-As grids, lowering elongation; adding tin offsets most of this.
      affects: Ductility of the cast grid
      source: dzenzerskiy2026
      where: Abstract and Results (Fig. 2b and Fig. 3b)
  handling:
    - text: Lead is a reproductive toxicant in the ECHA record (H360 notified by 84.4% of reports). Keep dust and fume out of work areas and follow the handling rules for lead in the lead profile.
      source: pubchem-lead
      where: GHS Classification (ECHA C&L Notifications Summary)
    - text: Antimony is harmful if swallowed or inhaled in the ECHA record (H302, H332), so avoid dust and fume from antimony-bearing alloys.
      source: pubchem-sb
      where: GHS Classification
    - text: WHO links exposure to lead-contaminated soil and dust from battery recycling and mining to outbreaks of mass lead poisoning, including child deaths in some countries.
      source: who-lead
      where: Sources and routes of exposure
  mitigations:
    - text: Medium-antimony alloys (3.0 to 4.0 wt% Sb) reduce the transfer of antimony to the negative plate and cut water loss, especially when arsenic and tin are added to keep the grid strong at lower antimony.
      source: dzenzerskiy2026
      where: Introduction, paragraph 3
    - text: Selenium addition reduces grain size in low-antimony alloys, according to the 1988 abstract.
      source: kim1988
      where: Abstract
uses:
  - application: batteries
    device: Cast positive and negative grids of lead-acid batteries (Pb-Sb grid alloys)
    example: Lead-antimony grids are commonly used in batteries today. Antimony gives the grid high charge-discharge performance and good castability. The paper's own tests used a Pb-3.5 wt% Sb grid alloy.
    source: dzenzerskiy2026
    where: Introduction, paragraph 1; Materials section
  - application: batteries
    device: Lead-acid batteries and US antimony and lead supply
    example: USGS reports that antimonial lead and ammunition took 40% of US antimony use in 2025, that recycling supplied 12% of US apparent antimony consumption, and that the lead-acid battery industry accounted for an estimated 67% of US apparent lead consumption in 2025.
    source: usgs-mcs2026-antimony
    where: Domestic Production and Use paragraph and Recycling (antimony chapter); the 67% figure is in the lead chapter, Domestic Production and Use paragraph (usgs-mcs2026-lead)
supply:
  - subject: Antimony
    producers:
      - country: China
        share_percent: 36.4
        year: 2025
      - country: Russia
        share_percent: 29.1
        year: 2025
      - country: Tajikistan
        share_percent: 20
        year: 2025
      - country: Burma
        share_percent: 4.1
        year: 2025
    critical_lists:
      - list: 'USGS 2025 List of Critical Minerals (antimony named: used in lead-acid batteries and flame retardants)'
        listed: true
      - list: EU critical raw materials list (Regulation (EU) 2024/1252, antimony named in the list of 34 critical raw materials)
        listed: true
    recycling: 'USGS: secondary antimony was recovered mostly at secondary lead smelters as antimonial lead, most of which the lead-acid battery industry generated and then consumed. Recycling supplied 12% of estimated domestic apparent consumption in 2025.'
    substitutes:
      - Combinations of calcium, copper, selenium, sulfur and tin substitute for antimony in alloys for lead-acid batteries (USGS).
    source: usgs-mcs2026-antimony
    where: World Mine Production and Reserves table (2025e; shares are calculated by Space Mushroom against the 110,000 t rounded world total, and may not add to 100); Domestic Production and Use; Recycling; Substitutes; critical lists from the USGS and EC pages
gaps:
  - The density of the lead-antimony alloy itself (1 to 12 wt% Sb) was not read. The density shown is for elemental antimony. A Matmatch datasheet was tried but the site was unreachable from this run.
  - No solidus or liquidus temperatures for Pb-Sb alloys were read. The 2018 Pb-Sb melt study covers 5 to 20 wt% Sb and gives thermodynamic results, but its full text was not opened, and the ASM phase diagram was not reachable.
  - No hardness (Brinell or Vickers) for lead-antimony alloys across the 1 to 12 wt% range was read in an opened source.
  - The 1 to 12 wt% Sb range is the scope of this profile. The sources read here cover 3.0 to 4.0 wt% (medium) and up to 3.5 wt% (automotive grids), and the tensile data are for Pb-3.5 wt% Sb only.
  - The Philippine Engineering Journal corrosion paper (Pb-Sb versus Pb-Ca) could not be opened (the download returned an error page), so no corrosion rate, weight loss or hydrogen overvoltage figure is entered.
  - No corrosion rate, weight loss or electrolyte test for lead-antimony alloys was read in full text. The corrosion rating in this file is qualitative only.
  - No antimony solubility-in-lead figure is entered; the value found in a search snippet was not read in a fetched page.
  - No ammunition product was read as a source for composition or hardness. The ammunition share (40%) is the USGS statistic only.
  - No lead-antimony shielding product or measured attenuation was sourced. The NIST values are for pure lead and pure antimony, and are not measurements of the alloy.
  - The NIST values at 500 keV (0.1614 and 0.09453 cm2/g) and 1.25 MeV (0.05876 and 0.05086 cm2/g) were read but not entered, because the NIST table prints them with a two-digit negative exponent (for example 1.614E-01) that the value check cannot match.
  - No space-environment data (vacuum, radiation, thermal cycling) and no flight use were found for antimonial lead.
  - No designations (UNS, EN, DIN, ASTM) were confirmed in an opened source for this alloy family. A DIN 17640 and ISO 4381 grade search was found but the pages were unreachable.
  - No media (images) were added to this profile.
  - Antimony abundance in the Earth's crust was not found in a checked source.
sources:
  pubchem-sb:
    title: 'PubChem compound record, Antimony (CID 5354495): experimental properties, GHS classification and identifiers'
    id: CID 5354495; CAS 7440-36-0
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON
    year: 2026
    kind: database
    license: public domain (NCBI)
  pubchem-lead:
    title: 'PubChem compound record, Lead (CID 5352425): GHS classification (ECHA C&L Inventory) and experimental properties'
    id: CID 5352425; CAS 7439-92-1
    url: https://pubchem.ncbi.nlm.nih.gov/compound/5352425
    year: 2026
    kind: database
    license: public domain (NCBI)
  nist-xray-z82:
    title: 'X-Ray Mass Attenuation Coefficients, Table 3: Lead (Z = 82) (NIST Physical Measurement Laboratory)'
    id: NIST Standard Reference Database 126, elemental media table
    url: https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z82.html
    year: 2004
    kind: database
    license: US government work
  nist-xray-z51:
    title: 'X-Ray Mass Attenuation Coefficients, Table 3: Antimony (Z = 51) (NIST Physical Measurement Laboratory)'
    id: NIST Standard Reference Database 126, elemental media table
    url: https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z51.html
    year: 2004
    kind: database
    license: US government work
  dzenzerskiy2026:
    title: Comparison of Sn and As effect on tensile properties of Pb-3.5%Sb grid alloy for lead-acid batteries
    id: doi:10.26565/2312-4334-2026-2-58 (East European Journal of Physics 2, 515-519, 2026)
    url: https://doi.org/10.26565/2312-4334-2026-2-58
    year: 2026
    kind: paper
    license: CC BY 4.0
  karazin2018:
    title: Thermodynamics and structural condition of Pb-Sb alloys (East European Journal of Physics, 2018)
    id: doi:10.26565/2312-4334-2018-1-06
    url: https://periodicals.karazin.ua/eejp/article/view/10464
    year: 2018
    kind: paper
    license: as listed by the journal
  kim1988:
    title: Structure and Corrosion Behavior of Low Antimony-Lead Alloys (Kim, Kang and Kang, Journal of the Korean Institute of Metals, 26(6), 1988)
    id: KJMM 26(6), 610-617, 1988
    url: https://kjmm.org/kjmm/ArticleDetail/RD_R/440952
    year: 1988
    kind: paper
    license: as listed by the journal (page states CC BY-NC 3.0 badge)
  usgs-mcs2026-antimony:
    title: 'Mineral Commodity Summaries 2026: Antimony (USGS)'
    id: USGS MCS 2026, antimony chapter
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-lead:
    title: 'Mineral Commodity Summaries 2026: Lead (USGS)'
    id: USGS MCS 2026, lead chapter
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS, published November 6, 2025; 60 minerals)
    id: USGS 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)
  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
  who-lead:
    title: Lead poisoning (WHO fact sheet)
    id: WHO fact sheet, updated 2026
    url: https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health
    year: 2026
    kind: report
    license: linked not reproduced
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 12
  unreachable: 4
  caveats: 6
  note: Written by an AI assistant on 2026-10-26. The values come from pages and PDFs fetched in this run (USGS PDFs read with pdftotext, NIST, PubChem JSON, the 2026 grid paper and the 1988 abstract). Matmatch, the Philippine corrosion paper, the Salford repository and the ASM handbook could not be opened. Alloy density, solidus and liquidus, and hardness are gaps, not values.
story:
  recipe:
    line: Antimonial lead is lead (Pb) with a small addition of antimony (Sb), in this profile's scope 1 to 12 wt% Sb. Grid alloys in the 2026 study are Pb-3.5 wt% Sb with arsenic or tin added. Lead-antimony alloys are cast into grids for lead-acid batteries, and USGS says secondary antimony is recovered from antimonial lead made from spent lead-acid batteries.
    parts:
      - name: Lead
        symbol: Pb
        role: The matrix, most of the weight. Lead is soft, and the antimony added to it sets the strength and castability.
      - name: Antimony
        symbol: Sb
        role: The hardening element, 1 to 12 wt% in scope. Higher antimony stiffens the grid but also drives antimony out of the positive grid over time.
  risk_groups:
    - title: For people
      level: 4
      verdict: Lead is a reproductive toxicant with no known safe level
      lead: Lead is the main hazard in this alloy, and the antimony adds harmful-if-swallowed and harmful-if-inhaled warnings.
      points:
        - label: Lead classification
          line: PubChem's ECHA summary for lead carries signal word Danger, with H360 (may damage fertility or the unborn child) notified by 84.4% and H372 (damage to organs through prolonged exposure) by 50.5%.
        - label: Children
          line: The WHO says there is no known safe blood lead concentration, and that young children may absorb up to 4 to 5 times as much lead as adults.
        - label: Antimony
          line: The ECHA summary for antimony shows H301 for 18.2% and H302 for 23.4% of reports, and H332 for 26.9%, all with signal word Danger.
    - title: If it fails
      lead: The failures for this alloy happen inside the battery, rather than in the metal itself.
      points:
        - label: Gassing and water loss
          line: The 2026 study says higher antimony raises gassing on charge and water loss, and that antimony dissolving from one plate and depositing on the other shortens battery life.
        - label: Cracking on casting
          line: Cutting antimony too far causes hot cracks along grain boundaries during casting, so the low-antimony grid needs other additions.
    - title: Handling and recycling
      points:
        - label: Battery recycling
          line: The WHO links dust and soil from battery recycling and mining to mass lead poisoning outbreaks, including child deaths in some countries.
        - label: Grid limit
          line: The 2026 study says automotive grid alloys are produced only up to 3.5 wt% Sb, and medium alloys of 3.0 to 4.0 wt% Sb lower the transfer of antimony to the negative plate.
  why: Antimonial lead is lead with a small amount of antimony. The antimony hardens the lead and gives it the castability needed for battery grids, but it does not stay put. Over the life of a lead-acid battery, antimony dissolves from the positive grid and deposits on the negative plate, which raises gassing, water loss and self-discharge. That trade is why automotive grid alloys are produced only up to 3.5 wt% Sb, and why arsenic and tin are added to keep the grid strong. USGS reports that antimonial lead and ammunition took 40% of US antimony use in 2025.
  uses:
    - where: Lead-acid battery grids
      line: The 2026 study says lead-antimony alloys are the common grid metal for lead-acid batteries, because antimony gives high charge-discharge performance and good castability. The paper's own tests used a Pb-3.5 wt% Sb grid alloy.
    - where: Lead-acid battery recycling
      line: USGS reports that in the United States, antimonial lead recovered from spent lead-acid batteries was the source of secondary antimony. Recycling supplied 12% of US apparent consumption, and the lead-acid battery industry accounted for an estimated 67% of US lead consumption in 2025.
    - where: Ammunition
      line: USGS says antimonial lead and ammunition took 40% of US antimony use in 2025. This profile does not use a specific ammunition product as a source, since none was read in this run.
  can_do:
    - label: Strength and stiffness
      benchmark: ultimate_tensile_strength
      value: 34.8 to 38.9 MPa
      line: A Pb-3.5 wt% Sb grid alloy with arsenic, as cast, had an ultimate tensile strength of 34.8 to 38.9 MPa, depending on the mold preheat temperature. Adding tin in place of some arsenic raised the strength to 38.9 to 40 MPa.
    - label: Stopping photons
      benchmark: mass_atten_100keV
      value: 5.549 cm2/g for lead at 100 keV
      line: Lead alone attenuates 5.549 cm2/g at 100 keV, against 1.758 cm2/g for antimony, so the attenuation of an alloy depends on how much lead it contains. The NIST values are for the elements, not for an alloy sample.
    - label: Density of the element
      benchmark: density
      value: 6.68 g/cm3 (antimony)
      line: Antimony itself has a density of 6.68 g/cm3 at 20 degC in the PubChem record. The density of the lead alloy was not found in a checked source.
  compare: The density and melting range of the lead-antimony alloy were not found in a checked source, so this profile compares the elements only. Pure antimony has a density of 6.68 g/cm3 and melts at 630.028 degC. Lead attenuates photons more strongly per gram at 100 keV (5.549 against 1.758 cm2/g for antimony). The 2026 study shows that tin in place of part of the arsenic keeps the grid stronger and more stable across casting temperatures.
  compare_rows:
    - label: Density of antimony
      benchmark: density
    - label: Melting point of antimony
      benchmark: melting_point
    - label: Attenuation at 100 keV, lead
      benchmark: mass_atten_100keV
  handling:
    - Lead in the alloy is a reproductive toxicant. Keep dust and fume out of work areas.
    - Antimony is harmful if swallowed or inhaled. Avoid dust from antimony-bearing alloys.
    - Treat spent batteries and grid scrap as hazardous. The WHO links careless recycling to mass lead poisoning.
  good_for:
    - Battery grids that need strength and castability from a small antimony addition. The 2026 study reports 34.8 to 40 MPa for a Pb-3.5 wt% Sb grid alloy.
    - A recycling chain that already exists. USGS says recycling supplied 12% of US apparent antimony consumption, recovered mainly as antimonial lead from spent batteries.
  watch_out:
    - Antimony leaves the positive grid over time, raising gassing, water loss and self-discharge. The paper's automotive limit is 3.5 wt% Sb.
    - Lead's toxicity. The ECHA summary notes H360 for 84.4% of reports, and the WHO says there is no known safe blood lead concentration.
    - Corrosion behavior is only described qualitatively here. No corrosion rate was read in full text.
  verdict: Antimonial lead is a cheap, castable lead alloy whose antimony gives the strength that battery grids need, but that antimony leaves the grid over time and costs water and battery life. The strength data here are for one grid alloy at 3.5 wt% Sb, and the alloy's density, melting range and hardness were not read, so this profile is a sourced draft, not a complete datasheet.