{ "spore": "profile", "id": "arsenic", "spore_version": "0.2", "family": "semiconductor-materials", "name": "Arsenic", "abbreviation": "As", "role": "Metalloid: feedstock for gallium arsenide semiconductors and a dopant", "category": "semiconductors", "type": "silicon", "summary": "Arsenic is the element As, a metalloid. WebElements gives its solid density as 5727 kg/m3, its melting point as 817 °C under pressure, and says it sublimes at 614 °C. In the United States its leading use was herbicides, insecticides and wood preservatives (USGS), but high-purity arsenic metal (99.9999%) is made into gallium arsenide and indium gallium arsenide semiconductors for satellites, solar cells and wireless devices. PubChem reports the element as toxic if swallowed or inhaled.", "best_for": "Source of high-purity arsenic metal for GaAs and InGaAs semiconductors and for specialty infrared optics (USGS)", "weakest_at": "Toxicity: PubChem reports H301 and H331 for most reporting companies, and ATSDR classes inorganic arsenic as a known human carcinogen", "identity": { "formula": "As, elemental arsenic, trigonal crystal (space group R-3m)", "crystal_system": "trigonal", "space_group": "R-3m", "designations": [], "source": "we-crystal", "where": "Crystal structures page, Space group row (R-3m, space group number 166); PubChem CID 5359596 for the element record" }, "tags": { "environments": [], "stresses": [], "applications": [ "electronics-and-chips", "solar-arrays", "optics-and-cameras" ] }, "properties": [ { "benchmark": "density", "label": "Density of the solid", "value": 5727, "bound": "exact", "unit": "kg/m3", "scope": "material", "conditions": { "temperature": "not stated on the page" }, "method": "Value printed on the WebElements physics page (printed as 5727 kg m-3)", "status": "ground", "source": "we-physics", "where": "Physics page, Density properties, Density of solid row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "elastic_modulus", "label": "Young's modulus", "value": 8, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated on the page" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Elastic properties, Young's modulus row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "bulk_modulus", "label": "Bulk modulus", "value": 22, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated on the page" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Elastic properties, Bulk modulus row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity", "value": 50, "bound": "exact", "unit": "W m-1 K-1", "scope": "material", "conditions": { "temperature": "not stated on the page" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Heat and conduction, Thermal conductivity row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "melting_point", "label": "Melting point under pressure", "value": 817, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "under pressure, value not stated on the page", "basis": "printed as 1090 K with 817 °C in brackets" }, "method": "Value printed on the WebElements thermochemistry page", "status": "ground", "note": "WebElements gives no liquid phase at normal pressure, so this is not an ambient-pressure melting point.", "source": "we-thermochemistry", "where": "Thermochemistry page, Melting point row", "source_detail": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "boiling_point", "label": "Sublimation point (printed as boiling point)", "value": 614, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "basis": "printed as 887 K with 614 °C in brackets and the note (sublimes)", "pressure": "not stated on the page" }, "method": "Value printed on the WebElements thermochemistry page with the note (sublimes)", "status": "ground", "source": "we-thermochemistry", "where": "Thermochemistry page, Boiling point row", "source_detail": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "enthalpy_of_fusion", "label": "Enthalpy of fusion", "value": 27.7, "bound": "exact", "unit": "kJ/mol", "scope": "material", "conditions": { "basis": "as printed on the page; no temperature stated" }, "method": "Value printed on the WebElements thermochemistry page", "status": "ground", "source": "we-thermochemistry", "where": "Thermochemistry page, Enthalpies, Enthalpy of fusion row", "source_detail": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "enthalpy_of_sublimation", "label": "Enthalpy of sublimation", "value": 32.4, "bound": "exact", "unit": "kJ/mol", "scope": "material", "conditions": { "basis": "printed as enthalpy of vaporisation with the note (sublimation)" }, "method": "Value printed on the WebElements thermochemistry page", "status": "ground", "source": "we-thermochemistry", "where": "Thermochemistry page, Enthalpies, Enthalpy of vaporisation row", "source_detail": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "enthalpy_of_atomisation", "label": "Enthalpy of atomisation", "value": 302, "bound": "exact", "unit": "kJ/mol", "scope": "material", "conditions": { "basis": "as printed on the page" }, "method": "Value printed on the WebElements thermochemistry page", "status": "ground", "source": "we-thermochemistry", "where": "Thermochemistry page, Enthalpies, Enthalpy of atomisation row", "source_detail": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "lattice_constant", "label": "Lattice parameter a", "value": 375.98, "bound": "exact", "unit": "pm", "scope": "material", "conditions": { "temperature": "not stated on the page", "structure": "trigonal, space group R-3m" }, "method": "Value printed on the WebElements crystal structure page", "status": "ground", "source": "we-crystal", "where": "Crystal structures page, a row", "source_detail": { "title": "WebElements, Arsenic: crystal structures (space group and lattice parameters)", "url": "https://www.webelements.com/arsenic/crystal_structure.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "lattice_constant", "label": "Lattice parameter c", "value": 1054.75, "bound": "exact", "unit": "pm", "scope": "material", "conditions": { "temperature": "not stated on the page", "structure": "trigonal, space group R-3m" }, "method": "Value printed on the WebElements crystal structure page", "status": "ground", "source": "we-crystal", "where": "Crystal structures page, c row", "source_detail": { "title": "WebElements, Arsenic: crystal structures (space group and lattice parameters)", "url": "https://www.webelements.com/arsenic/crystal_structure.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "molar_volume", "label": "Molar volume", "value": 12.95, "bound": "exact", "unit": "cm3", "scope": "material", "conditions": { "temperature": "not stated on the page" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Density properties, Molar volume row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "electronegativity", "label": "Pauling electronegativity", "value": 2.18, "bound": "exact", "unit": "Pauling units", "scope": "material", "conditions": { "scale": "Pauling" }, "method": "Value printed on the WebElements main element page", "status": "ground", "source": "we-main", "where": "Main page, Electronegativity section, Pauling electronegativity row", "source_detail": { "title": "WebElements, Arsenic: element page (relative atomic mass, electronegativity)", "url": "https://www.webelements.com/arsenic/", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "mineral_hardness", "label": "Mineral hardness", "value": 3.5, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "scale": "mineral hardness scale as printed (no units)" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Hardnesses, Mineral hardness row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } }, { "benchmark": "brinell_hardness", "label": "Brinell hardness", "value": 1440, "bound": "exact", "unit": "MN/m2", "scope": "material", "conditions": { "basis": "as printed on the page; no load or test conditions given" }, "method": "Value printed on the WebElements physics page", "status": "ground", "source": "we-physics", "where": "Physics page, Hardnesses, Brinell hardness row", "source_detail": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" } } ], "corrosion": [ { "environment": "Dry air at room temperature", "headline": "Arsenic is stable in dry air.", "effect": "WebElements says arsenic is stable in dry air. No rate or thickness is given.", "rating": "none", "conditions": { "basis": "rating is the assistant's reading of the wording, not a printed rating" }, "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph" }, { "environment": "Moist air at room temperature", "headline": "The surface tarnishes slowly in moist air.", "effect": "WebElements says the surface oxidizes slowly in moist air, first to a bronze tarnish and finally to a black covering. No time, humidity or thickness is given.", "rating": "low", "conditions": { "basis": "rating is the assistant's reading of the wording; no rate given" }, "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph" }, { "environment": "Water in the absence of air", "headline": "Arsenic does not react with water without air under normal conditions.", "effect": "WebElements says arsenic does not react with water in the absence of air under normal conditions.", "rating": "none", "conditions": { "basis": "normal conditions as stated on the page; no temperature given" }, "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with water paragraph" }, { "environment": "Heated in air or oxygen", "headline": "Heated arsenic ignites and forms arsenic oxides.", "effect": "WebElements says that when heated in air arsenic ignites to form As4O6, with phosphorescence under some conditions. In oxygen it ignites to form As4O10 and As4O6. No ignition temperature is given.", "rating": "severe", "conditions": { "basis": "rating is the assistant's reading of the ignition wording; no temperature given" }, "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph and equations" }, { "environment": "Halogens (fluorine, chlorine, bromine and iodine)", "headline": "Arsenic reacts with the halogens to form halides.", "effect": "WebElements says arsenic reacts with fluorine to form arsenic(V) fluoride, and under controlled conditions with chlorine, bromine and iodine to form the arsenic(III) trihalides.", "rating": "severe", "conditions": { "basis": "reactions as written on the page; no temperatures or rates given" }, "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with the halogens paragraph and equations" } ], "risks": { "hazards": [ { "text": "PubChem's ECHA-based aggregate for arsenic (1439 company reports from 20 notifications) gives H301 toxic if swallowed (above 99.9 percent of reporting companies), H331 toxic if inhaled (above 99.9 percent), H400 very toxic to aquatic life (99.9 percent), H410 very toxic to aquatic life with long lasting effects (above 99.9 percent), and H350 may cause cancer (45.8 percent).", "ghs": [ "H301: Toxic if swallowed", "H331: Toxic if inhaled", "H350: May cause cancer", "H400: Very toxic to aquatic life", "H410: Very toxic to aquatic life with long lasting effects", "H315: Causes skin irritation", "H318: Causes serious eye damage" ], "source": "pubchem-as", "where": "Safety and Hazards, GHS Classification, ECHA C&L Notifications Summary (CID 5359596)" }, { "text": "PubChem's summary gives the signal word Danger. The statement text for the precautionary codes was not checked, so use the supplier safety data sheet for the form handled.", "ghs": [], "source": "pubchem-as", "where": "Safety and Hazards, GHS Classification, Signal Word row" }, { "text": "ATSDR ToxFAQs says that the US Department of Health and Human Services, IARC and EPA all classify inorganic arsenic as a known human carcinogen, and that swallowing it long term causes skin changes and skin cancer. The ToxFAQ covers inorganic arsenic, the form of most concern, rather than the element alone.", "ghs": [], "source": "atsdr-faq", "where": "ToxFAQs page, health effects answers (carcinogen and skin effects paragraphs)" } ], "failure_risks": [ { "mode": "Ignition of the element when heated in air", "trigger": "Heating in air or oxygen", "consequence": "WebElements says arsenic ignites and forms arsenic oxides (As4O6 and As4O10), with phosphorescence under some conditions.", "severity": "high", "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph" }, { "mode": "Supply concentrated in few producers", "trigger": "Peru, China and Morocco supplied more than 95 percent of world arsenic trioxide in 2025 (USGS)", "consequence": "The United States imports all of the arsenic it uses (net import reliance 100 percent in every year from 2021 to 2025e), and China supplied more than 90 percent of US arsenic metal imports through July 2025.", "severity": "high", "source": "usgs-as-2026", "where": "Events, Trends, and Issues; Salient Statistics, Net import reliance row" }, { "mode": "Surface tarnish in moist air", "trigger": "Storage in moist air", "consequence": "WebElements says the surface oxidizes slowly to a bronze tarnish and finally a black covering. No rate is given.", "severity": "low", "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph" } ], "side_effects": [], "handling": [ { "text": "The US Occupational Safety and Health Administration sets a permissible exposure limit of 10 micrograms per cubic metre of air, as an 8-hour time-weighted average, for airborne inorganic arsenic (ATSDR ToxFAQs).", "source": "atsdr-faq", "where": "ToxFAQs page, paragraph on the federal government steps to protect people from arsenic" }, { "text": "Breathing high levels of inorganic arsenic causes sore throat and irritated lungs. ATSDR says the level that causes these effects is probably above 100 micrograms per cubic metre for a brief exposure.", "source": "atsdr-faq", "where": "ToxFAQs page, paragraph on breathing high levels" }, { "text": "Heating arsenic in air ignites it (WebElements), so heating needs a controlled atmosphere.", "source": "we-chem", "where": "Chemistry page, Reaction of arsenic with air paragraph" } ], "mitigations": [] }, "uses": [ { "application": "electronics-and-chips", "device": "Gallium arsenide and indium gallium arsenide semiconductors", "example": "USGS says high-purity (99.9999%) arsenic metal was used to produce GaAs, indium arsenide and InGaAs semiconductors for aerospace devices, satellites, mobile devices, optoelectronic devices and wireless communications.", "source": "usgs-as-2026", "where": "Events, Trends, and Issues; Domestic Production and Use" }, { "application": "solar-arrays", "device": "Gallium arsenide solar cells for space and terrestrial power", "example": "USGS says GaAs semiconductors made from high-purity arsenic metal are used in solar cells, space research and telecommunications, and that silicon is the principal competitor with GaAs in solar cells.", "source": "usgs-as-2026", "where": "Domestic Production and Use; Substitutes" }, { "application": "optics-and-cameras", "device": "Specialty infrared optics and shortwave infrared sensors", "example": "USGS lists germanium arsenide selenide specialty optical materials and indium gallium arsenide for shortwave infrared technology among the uses of high-purity arsenic metal.", "source": "usgs-as-2026", "where": "Domestic Production and Use" }, { "application": "electronics-and-chips", "device": "Dopant in solid-state devices such as transistors", "example": "WebElements lists doping agent in solid-state devices such as transistors among the uses of arsenic. The page says its uses are gathered from several sources and from anecdotal comments.", "source": "we-uses", "where": "Uses page, list of uses" } ], "supply": [ { "subject": "Arsenic (arsenic trioxide, the main commercial compound, and high-purity metal)", "abundance": "No crustal abundance figure was read in this pass. USGS says arsenic is recovered from copper, gold and lead smelter flue dust and from roasting arsenopyrite, and that world reserves were not reported but were estimated to be more than 20 times world production.", "producers": [ { "country": "Peru", "share_percent": 49.2, "year": 2025 }, { "country": "China", "share_percent": 39.3, "year": 2025 }, { "country": "Morocco", "share_percent": 8.2, "year": 2025 }, { "country": "Belgium", "share_percent": 1.6, "year": 2025 }, { "country": "Russia", "share_percent": 0.8, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals (IEA summary of the final list names arsenic)", "listed": true }, { "list": "EU critical raw materials list (2023 fifth list of 34 CRMs, Regulation (EU) 2024/1252)", "listed": true } ], "recycling": "USGS: arsenic metal was contained in new scrap recycled during GaAs semiconductor manufacturing. No arsenic was known to be recovered from scrap electronic boards during recycling for other metals.", "substitutes": [ "USGS: silicon is the principal competitor with GaAs in solar cells, and no effective substitutes exist for GaAs in many defense-related applications. Indium phosphide can replace GaAs in some infrared laser diodes." ], "source": "usgs-as-2026", "where": "World Production and Capacity table (2025, arsenic trioxide gross weight; shares calculated by Space Mushroom against the 61000 t world total); Import Sources (2021 to 2024); Salient Statistics; Recycling; Substitutes" } ], "media": [], "documents": [ { "title": "USGS Mineral Commodity Summaries 2026, Arsenic", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-arsenic.pdf", "year": 2026 }, { "title": "PubChem: Arsenic (CID 5359596), GHS classification summary", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/5359596", "year": 2026 }, { "title": "ATSDR ToxFAQs: Arsenic", "type": "report", "url": "https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=18&toxid=3" } ], "gaps": [ "Electrical resistivity: WebElements prints it as 33 with a 10 to the minus 8 exponent in ohm metres. It is left out because the value is written in exponent form.", "Dopant data (solubility of arsenic in silicon or germanium, carrier concentration, donor behaviour) were not found in a source read in this pass.", "Crustal abundance: the WebElements abundance field was not captured, and USGS gives no abundance figure.", "Occupational exposure limit from NIOSH: the NIOSH pocket guide page returned Access Denied. The OSHA limit is taken from the ATSDR ToxFAQ instead, and it is for inorganic arsenic.", "Acid and alkali corrosion: WebElements has reaction sections for acids and bases, but their text was not captured.", "No vacuum, radiation, thermal-vacuum or flight result for the element was found. Its space use is through GaAs devices and solar cells, as USGS describes.", "Hazard data for the elemental form rest on the PubChem aggregate and the ATSDR ToxFAQ (which covers inorganic arsenic). No supplier safety data sheet for the element was read.", "Melting point is printed under pressure, and WebElements gives no ambient-pressure melting point.", "Property names not in spores/property-canon.yaml and used here: enthalpy_of_fusion, enthalpy_of_sublimation, enthalpy_of_atomisation, molar_volume, electronegativity, mineral_hardness, brinell_hardness, lattice_constant. Density, elastic_modulus, bulk_modulus, thermal_conductivity, melting_point, boiling_point and electronegativity are canonical or aliased.", "The EU list and the USGS 2025 list are cited through the EC page and the IEA summary of the USGS list. The USGS critical-minerals page itself could not be opened." ], "story": { "why": "Arsenic is a metalloid. Its main technical use is in semiconductors: high-purity arsenic metal makes gallium arsenide and related compounds used in satellites, solar cells and wireless devices. Its toxicity is high, so PubChem and ATSDR both flag it, and handling needs care.", "uses": [ { "where": "Semiconductors and solar cells", "line": "USGS says high-purity arsenic metal makes GaAs, indium arsenide and InGaAs semiconductors used in satellites, aerospace devices, photovoltaic applications and mobile devices." }, { "where": "Infrared and specialty optics", "line": "USGS lists germanium arsenide selenide specialty optical materials and indium gallium arsenide for shortwave infrared sensing as uses of the metal." }, { "where": "Dopant", "line": "WebElements lists a doping agent in solid-state devices such as transistors among the uses of arsenic." } ], "can_do": [ { "label": "Density", "line": "The solid has a density of 5727 kg/m3 (WebElements), printed as 5727 kg m-3.", "benchmark": "density", "scope": "material", "value": "5727 kg/m3" }, { "label": "Melt", "line": "WebElements gives 817 °C as the melting point under pressure. It says there is no liquid phase at normal pressure, and that the element sublimes at 614 °C.", "benchmark": "melting_point", "scope": "material", "value": "817 °C under pressure" }, { "label": "Carry heat", "line": "Thermal conductivity is printed as 50 W m-1 K-1 (WebElements), with no temperature given.", "benchmark": "thermal_conductivity", "scope": "material", "value": "50 W m-1 K-1" }, { "label": "Stiffness", "line": "WebElements prints Young's modulus as 8 GPa and the bulk modulus as 22 GPa.", "benchmark": "elastic_modulus", "scope": "material", "value": "8 GPa" } ], "compare": "The table compares the element's density, melting point and thermal conductivity. Arsenic is best known in devices through its compounds with gallium and indium, which carry most of the semiconductor and optical uses cited by the USGS. The element itself is toxic and ignites when heated in air.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Melting point under pressure", "benchmark": "melting_point", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Treat arsenic as toxic: PubChem reports H301 and H331 (toxic if swallowed or inhaled) for most reporting companies.", "Keep airborne exposure under the OSHA limit of 10 micrograms per cubic metre, an 8-hour average, for inorganic arsenic (ATSDR).", "Heating in air ignites the element (WebElements), so heat it under a controlled atmosphere." ], "good_for": [ "Source of high-purity arsenic metal for GaAs and InGaAs semiconductors used in satellites and solar cells (USGS).", "Dopant in solid-state devices such as transistors (WebElements)." ], "watch_out": [ "Toxicity: PubChem reports H301 and H331 for most reporting companies, and ATSDR classes inorganic arsenic as a known human carcinogen.", "Heating in air ignites the element, forming arsenic oxides (WebElements).", "Supply concentration: USGS says Peru, China and Morocco supplied more than 95 percent of world arsenic trioxide in 2025." ], "verdict": "Arsenic is well documented as a semiconductor feedstock. Its density, melting point and thermal constants come from WebElements, and its use and supply come from the USGS. Its toxicity is the limiting factor. The sources read did not give a dopant solubility figure, a crustal abundance or an NIOSH exposure limit.", "recipe": { "line": "Arsenic is the element As (PubChem). WebElements gives its crystal as trigonal, space group R-3m. USGS says arsenic is obtained from copper, gold and lead smelter flue dust and by roasting arsenopyrite, and that high-purity metal is made for GaAs semiconductors.", "parts": [ { "name": "Arsenic", "symbol": "As", "role": "The element itself. High-purity metal is the feedstock for GaAs and InGaAs semiconductors (USGS).", "atoms": 1, "atomic_weight": 74.921595, "share_percent": 100, "source": "nist-as", "where": "Atomic weights table, As row (standard atomic weight with uncertainty printed in the table)" } ] }, "risk_groups": [ { "title": "For people", "lead": "PubChem's aggregate classes arsenic as toxic if swallowed or inhaled, and the US health department, IARC and EPA classify inorganic arsenic as a human carcinogen.", "points": [ { "label": "Swallowing or breathing", "line": "PubChem's aggregate gives H301 (toxic if swallowed) and H331 (toxic if inhaled) for more than 99.9 percent of the companies that report those codes. ATSDR says high levels of inorganic arsenic in air cause sore throat and irritated lungs." }, { "label": "Long-term exposure", "line": "ATSDR says that long-term oral exposure to inorganic arsenic causes darkened patches of skin and wart-like corns, and that it can increase the risk of cancer in the liver, bladder and lungs." }, { "label": "Workplace limit", "line": "The OSHA permissible exposure limit for airborne inorganic arsenic is 10 micrograms per cubic metre, as an 8-hour average, according to ATSDR." } ], "level": 3, "verdict": "Toxic if swallowed or inhaled; known human carcinogen" }, { "title": "If it fails", "lead": "The failure routes in the sources read are ignition on heating and a supply that depends on a few producers.", "points": [ { "label": "Heat", "line": "WebElements says heated arsenic ignites in air and forms arsenic oxides, with phosphorescence under some conditions." }, { "label": "Supply", "line": "USGS says Peru, China and Morocco supplied more than 95 percent of world arsenic trioxide in 2025, and the United States imports all of the arsenic it uses." } ] } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 15, "unreachable": 1, "caveats": 2, "note": "Written by an AI assistant from pages fetched on 2026-10-26. The NIOSH page was blocked, and the USGS critical-minerals page could not be opened." }, "sources": { "we-physics": { "title": "WebElements, Arsenic: physical properties (density, elastic, hardness and electrical data)", "url": "https://www.webelements.com/arsenic/physics.html", "kind": "web", "license": "page content, cited as published" }, "we-thermochemistry": { "title": "WebElements, Arsenic: thermochemistry (melting and boiling points, enthalpies)", "url": "https://www.webelements.com/arsenic/thermochemistry.html", "kind": "web", "license": "page content, cited as published" }, "we-crystal": { "title": "WebElements, Arsenic: crystal structures (space group and lattice parameters)", "url": "https://www.webelements.com/arsenic/crystal_structure.html", "kind": "web", "license": "page content, cited as published" }, "we-main": { "title": "WebElements, Arsenic: element page (relative atomic mass, electronegativity)", "url": "https://www.webelements.com/arsenic/", "kind": "web", "license": "page content, cited as published" }, "we-chem": { "title": "WebElements, Arsenic: chemistry (reactions with air, water and halogens)", "url": "https://www.webelements.com/arsenic/chemistry.html", "kind": "web", "license": "page content, cited as published" }, "we-uses": { "title": "WebElements, Arsenic: uses", "url": "https://www.webelements.com/arsenic/uses.html", "kind": "web", "license": "page content, cited as published" }, "pubchem-as": { "title": "PubChem compound record, Arsenic (CID 5359596), GHS classification", "id": "CID 5359596", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/5359596", "year": 2026, "kind": "database", "license": "public domain (NCBI)" }, "nist-as": { "title": "NIST, Atomic weights and isotopic compositions for arsenic (As)", "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=As&all=all&ascii=html", "kind": "database", "license": "public domain (NIST)" }, "usgs-as-2026": { "title": "USGS Mineral Commodity Summaries 2026, Arsenic (February 2026)", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-arsenic.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "atsdr-faq": { "title": "ATSDR ToxFAQs, Arsenic", "url": "https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=18&toxid=3", "kind": "handbook", "license": "public domain (CDC/ATSDR)" }, "iea-crit-2025": { "title": "IEA, Final List of Critical Minerals 2025 (summary of the USGS list, updated July 2026)", "url": "https://www.iea.org/policies/31799", "year": 2026, "kind": "web", "license": "page content, cited as published" }, "ec-crm": { "title": "European Commission, Critical raw materials (2023 fifth list of 34 CRMs, 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" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/arsenic/" }