{
  "vercy": "1.0-draft",
  "publication": {
    "status": "research-draft",
    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-12T12:01:48Z",
    "providers": [
      "Codex"
    ],
    "breadth": "recalled by Codex without web access - no source was read",
    "missingProviders": [],
    "pass": 2,
    "cost": {
      "grok": {
        "seconds": 20.6,
        "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.4\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a0957d-7bfb-78a1-be10-ec454654ece0\n--------\nuser\nDescribe what is already known about one registered thing. Answer as JSON only, no prose around it.\n\nThing: peroxodisulfate\nSense to describe: (none recorded)\nDomain code: PHY.MAT\nAlso known as: (none)\n\n\nContext for this batch of 1001 things:\n# Batch 044: 1001",
        "usd": 0.0,
        "recall": true
      },
      "codex": {
        "seconds": 84.2,
        "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.4\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a0957d-7bf3-7c22-a2a5-94dbf5293ede\n--------\nuser\nYou are drafting a Vercy meta-model for one registered thing. Answer as JSON only, no prose around it.\n\nThing: peroxodisulfate\nRegistry id: vr.tr.peroxodisulfate\nPlane / domain: PHY / PHY.MAT\nRegistry definition: (none recorded)\nNames folded into this entry: ("
      }
    },
    "enrichment": {
      "pass": 3,
      "engine": "claude",
      "producedAt": "2026-10-06T12:00:00Z",
      "ingestedAt": "2026-10-06T08:51:20+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "failure_modes_and_hazards",
        "owners",
        "standards_and_regulation",
        "visual_identification"
      ]
    },
    "gate": {
      "passed": true,
      "version": "1.0",
      "at": "2026-10-07T10:10:30+00:00",
      "evidence": [
        "completeness 1.00",
        "sense: Wikidata description",
        "2 live sources",
        "review by codex: pass"
      ]
    }
  },
  "metaModel": {
    "id": "THING-Q413093",
    "registryId": "vr.tr.peroxodisulfate",
    "name": "peroxodisulfate",
    "version": "0.1.0-research.1",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "PHY.MAT"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q413093/",
  "model": {
    "registry_id": "vr.tr.peroxodisulfate",
    "name": "peroxodisulfate",
    "purpose": "Enable an agent to identify peroxodisulfate, assess its condition in a specified material, and determine which uses or handling actions are supported by evidence.",
    "definition": "Peroxodisulfate is the dianion S₂O₈²⁻, containing two sulfate-like groups joined through a peroxide O-O bond, and is the oxidizing constituent of salts commonly called persulfates.",
    "scope_statement": "This model owns vr.tr.peroxodisulfate in PHY / PHY.MAT, provisionally interpreted as the peroxodisulfate anion and its shared chemical behavior, with explicit links to the salts, solutions, and formulations in which it occurs.",
    "in_scope": [
      "Anion identity, molecular connectivity, charge, synonyms, and identifier provenance",
      "Counterion and formulation context needed to interpret a peroxodisulfate sample",
      "Peroxodisulfate content, assay selectivity, impurities, and degradation state",
      "Condition-dependent persistence, activation, and oxidizing behavior",
      "Evidence connecting material-specific hazards and restrictions to permitted actions"
    ],
    "out_of_scope": [
      "Complete standalone models of sodium, potassium, or ammonium peroxodisulfate",
      "Peroxymonosulfate, sulfate, and peroxydisulfuric acid as separate substances",
      "Commercial product recipes, packaging designs, and supplier operations",
      "Design and operation of manufacturing or treatment plants",
      "Complete models of treated substrates, pollutants, or polymer products"
    ],
    "distinguishing_features": [
      "Require the dianion formula S2O8^2− and a peroxide bridge connecting two sulfur-containing groups; a name containing 'persulfate' alone is insufficient. [ChEBI identity record](https://www.ebi.ac.uk/chebi/CHEBI%3A29267)",
      "Distinguish peroxymonosulfate by its single sulfur atom and different connectivity; do not merge it solely because a source calls both species persulfates. [ChEBI peroxymonosulfate record](https://www.ebi.ac.uk/chebi/fr/searchId.do?chebiId=29288&locale=null&printerFriendlyView=true&structureView=applet&viewTermLineage=)",
      "Distinguish sulfate and disulfate using peroxide connectivity as well as elemental composition.",
      "Distinguish the anion from a bulk salt by requiring the counterion, stoichiometry, and material form before assigning physical constants or regulatory identifiers.",
      "Distinguish intact peroxodisulfate from an activated reaction mixture through species-specific evidence rather than total oxidizing capacity alone."
    ],
    "characteristics": [
      {
        "name": "Chemical identity",
        "kind": "category",
        "unit_or_values": "S2O8^2−; structure representation; verified synonyms",
        "why_it_matters": "Prevents confusion between peroxodisulfate and other substances sold or described as persulfates."
      },
      {
        "name": "Identifier assignment",
        "kind": "relation",
        "unit_or_values": "Identifier system, value, issuing source, and entity identified",
        "why_it_matters": "Keeps anion identifiers separate from CAS, EC, or PubChem identifiers belonging to individual salts."
      },
      {
        "name": "Counterion and formulation",
        "kind": "relation",
        "unit_or_values": "Counterion identity and stoichiometry; solvent; additives; linked material record",
        "why_it_matters": "Determines which material properties and handling evidence apply."
      },
      {
        "name": "Peroxodisulfate content",
        "kind": "measurement",
        "unit_or_values": "mol/L, mmol/kg, or mass fraction explicitly expressed as S2O8^2− or named salt",
        "why_it_matters": "Supports defensible quantity comparisons without mixing salt mass and anion mass."
      },
      {
        "name": "Grade and impurity profile",
        "kind": "category",
        "unit_or_values": "Declared grade; specification limits; measured sulfate, other oxidants, metals, and moisture where relevant",
        "why_it_matters": "Separates nominal purity from suitability for a particular analytical or reactive use."
      },
      {
        "name": "Material state and conditions",
        "kind": "state",
        "unit_or_values": "Solid salt, solution, or formulated mixture; temperature in °C; solvent; pH where applicable",
        "why_it_matters": "Makes condition-dependent observations interpretable."
      },
      {
        "name": "Physical property evidence",
        "kind": "measurement",
        "unit_or_values": "Solubility in g/L; density in kg/m³; thermal transitions in °C; named material and test conditions",
        "why_it_matters": "Prevents assigning a salt's melting behavior or solubility to the anion itself and distinguishes decomposition from boiling."
      },
      {
        "name": "Residual content over time",
        "kind": "measurement",
        "unit_or_values": "Remaining S2O8^2− concentration or fraction, elapsed time, and storage or reaction conditions",
        "why_it_matters": "Supports stability judgments using measured retention rather than appearance."
      },
      {
        "name": "Activation and reaction evidence",
        "kind": "state",
        "unit_or_values": "Unactivated, deliberately activated, activation suspected, or unknown; method and evidence",
        "why_it_matters": "Separates the starting oxidant from claims about transient species and reaction performance."
      },
      {
        "name": "Applicable hazard and exposure record",
        "kind": "relation",
        "unit_or_values": "Exact material, GHS jurisdiction and edition, SDS revision, exposure limit and averaging period where established",
        "why_it_matters": "Ties handling decisions to the material actually present instead of assuming one classification covers every peroxodisulfate form."
      }
    ],
    "affordances": [
      "Resolve a reported persulfate identity against structure, formula, and counterion evidence.",
      "Compare samples after normalizing their reported content to a common chemical basis.",
      "Assess whether assay results distinguish peroxodisulfate from other oxidants and degradation products.",
      "Judge whether storage history and residual-content evidence support a proposed use.",
      "Evaluate whether an activation or oxidation claim is supported under the stated conditions.",
      "Route handling, compatibility, and disposal decisions to verified guidance for the exact salt or formulation."
    ],
    "agent_conduct": {
      "may": [
        "Explain peroxodisulfate chemistry and the uses of persulfate salts in general terms.",
        "Report hazard classification, storage and handling rules from safety data sheets.",
        "Advise keeping persulfates away from combustible materials and reducing agents."
      ],
      "must_not": [
        "Store or ship persulfates together with combustible or incompatible materials.",
        "Provide instructions for using persulfates to start fires or cause harm.",
        "Handle persulfate dusts without the respiratory protection the safety data sheet requires.",
        "Dispose of persulfate solutions into drains against local rules."
      ],
      "requires_human": [
        "Approving use of persulfate products in hair bleaching or other consumer settings."
      ]
    },
    "ethics": {
      "considerations": [
        "Persulfates can cause asthma and skin sensitization in workers such as hairdressers.",
        "Strong oxidizers can start fires that endanger bystanders."
      ],
      "affected_parties": [
        "Workers handling persulfates",
        "Hairdressers and their clients",
        "Emergency responders"
      ]
    },
    "owners": {
      "steward": "The person or business that holds it; chemical safety authorities regulate supply and use.",
      "master_systems": [
        "National chemical inventories"
      ]
    },
    "visual_identification": [
      "Persulfate salts appear as white crystalline powders or granules.",
      "Containers carry oxidizer and respiratory sensitizer hazard pictograms."
    ],
    "failure_modes_and_hazards": [
      "Fire when mixed with combustible or reducing materials.",
      "Respiratory and skin sensitization.",
      "Eye and skin irritation."
    ],
    "standards_and_regulation": [
      "Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations."
    ],
    "what_it_is_for": [
      "Peroxodisulfate is encountered as the oxidizing ion in persulfate salts used in chemical manufacturing and laboratory work.",
      "Its salts are used as polymerization initiators and in selected oxidation, surface treatment and environmental remediation processes.",
      "The counterion, concentration and surrounding formulation determine how a particular material can be assessed and used."
    ]
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q413093: peroxodisulfate",
      "url": "https://www.wikidata.org/wiki/Q413093",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: Peroxydisulfate",
      "url": "https://en.wikipedia.org/wiki/Peroxydisulfate",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "peroxodisulfate-identity",
        "name": "Peroxodisulfate identity",
        "description": "Resolve the chemical species behind the registry name and preserve its boundaries.",
        "rationale": "Persulfate terminology can obscure differences between anions, acids, salts, and mixtures.",
        "layers": [
          {
            "id": "anion-structure",
            "name": "Anion structure",
            "description": "Record the structural evidence that establishes peroxodisulfate identity.",
            "findings": [
              {
                "id": "formula-charge-connectivity",
                "name": "Formula, charge, and connectivity",
                "description": "Require agreement between elemental composition, ionic charge, and peroxide connectivity.",
                "questions": [
                  {
                    "text": "Which authoritative structure record establishes that this entry denotes S2O8^2−?",
                    "kind": "definition",
                    "id": "formula-charge-connectivity-q01"
                  },
                  {
                    "text": "What structural evidence excludes sulfate, disulfate, and peroxymonosulfate?",
                    "kind": "boundary",
                    "id": "formula-charge-connectivity-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "names-and-entity-links",
            "name": "Names and entity links",
            "description": "Associate names and identifiers with the correct chemical entity.",
            "findings": [
              {
                "id": "identifier-scope",
                "name": "Identifier scope",
                "description": "Resolve whether each identifier denotes the anion, an individual salt, an acid, or a commercial mixture.",
                "questions": [
                  {
                    "text": "Which CAS, PubChem, ChEBI, and EC identifiers are verified for the anion, and which belong only to linked materials?",
                    "kind": "provenance",
                    "id": "identifier-scope-q01"
                  },
                  {
                    "text": "Does the registry's originating record denote the anion specifically or a broader class of peroxodisulfate salts?",
                    "kind": "boundary",
                    "id": "identifier-scope-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "material-realization",
        "name": "Material realization",
        "description": "Connect the shared anion to the particular salt, solution, or formulation being assessed.",
        "rationale": "Bulk properties and usable quantities cannot be inferred from anion identity alone.",
        "layers": [
          {
            "id": "counterions-and-grade",
            "name": "Counterions and grade",
            "description": "Establish the composition and specification of the material carrying peroxodisulfate.",
            "findings": [
              {
                "id": "sample-composition",
                "name": "Sample composition",
                "description": "Capture counterion stoichiometry, solvent, additives, purity basis, and lot evidence.",
                "questions": [
                  {
                    "text": "Which counterions, solvents, and additives are present in the assessed material?",
                    "kind": "definition",
                    "id": "sample-composition-q01"
                  },
                  {
                    "text": "What lot-specific evidence supports the declared grade, moisture content, and impurity limits?",
                    "kind": "provenance",
                    "id": "sample-composition-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "phase-and-property-context",
            "name": "Phase and property context",
            "description": "Attach measured physical properties to their material and environmental conditions.",
            "findings": [
              {
                "id": "applicable-physical-properties",
                "name": "Applicable physical properties",
                "description": "Separate salt and solution measurements from properties attributed to the chemical species.",
                "questions": [
                  {
                    "text": "For which exact salt or formulation, solvent, temperature, and pressure were solubility and density measured?",
                    "kind": "measurement",
                    "id": "applicable-physical-properties-q01"
                  },
                  {
                    "text": "Does a reported thermal value describe melting, decomposition, or another event, and is a boiling point applicable?",
                    "kind": "boundary",
                    "id": "applicable-physical-properties-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "content-and-integrity",
        "name": "Content and integrity",
        "description": "Establish how much intact peroxodisulfate is present and how confidently it is known.",
        "rationale": "Nominal salt content and total oxidizing capacity do not by themselves establish intact peroxodisulfate concentration.",
        "layers": [
          {
            "id": "selective-quantification",
            "name": "Selective quantification",
            "description": "Evaluate assay basis, specificity, and uncertainty.",
            "findings": [
              {
                "id": "assay-interpretation",
                "name": "Assay interpretation",
                "description": "Normalize results while preserving what the analytical method actually measures.",
                "questions": [
                  {
                    "text": "Is the result expressed as intact S2O8^2−, named salt, active oxygen, or oxidizing equivalents?",
                    "kind": "measurement",
                    "id": "assay-interpretation-q01"
                  },
                  {
                    "text": "How does the method account for other oxidants, matrix interference, recovery, and measurement uncertainty?",
                    "kind": "measurement",
                    "id": "assay-interpretation-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "aging-and-degradation",
            "name": "Aging and degradation",
            "description": "Relate remaining content and composition changes to sample history.",
            "findings": [
              {
                "id": "retained-peroxodisulfate",
                "name": "Retained peroxodisulfate",
                "description": "Base condition judgments on time-resolved evidence and documented storage conditions.",
                "questions": [
                  {
                    "text": "How much intact peroxodisulfate remains after the recorded storage or solution-aging interval?",
                    "kind": "measurement",
                    "id": "retained-peroxodisulfate-q01"
                  },
                  {
                    "text": "Which observed changes or validated acceptance limits require re-assay, rejection, or restricted use?",
                    "kind": "action",
                    "id": "retained-peroxodisulfate-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "oxidation-and-activation",
        "name": "Oxidation and activation",
        "description": "Represent reaction capability without treating every peroxodisulfate system as mechanistically identical.",
        "rationale": "An agent needs condition-specific evidence to connect oxidant presence with reaction rate, mechanism, and useful outcome.",
        "layers": [
          {
            "id": "activation-context",
            "name": "Activation context",
            "description": "Record conditions proposed to activate peroxodisulfate and evidence for reactive intermediates.",
            "findings": [
              {
                "id": "supported-activation-mechanism",
                "name": "Supported activation mechanism",
                "description": "Separate an applied treatment from proof of the species or pathways it produces.",
                "questions": [
                  {
                    "text": "What thermal, photochemical, catalytic, electrochemical, or other activation conditions were applied?",
                    "kind": "provenance",
                    "id": "supported-activation-mechanism-q01"
                  },
                  {
                    "text": "What evidence distinguishes proposed sulfate-radical, other radical, or nonradical pathways in this system?",
                    "kind": "measurement",
                    "id": "supported-activation-mechanism-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "matrix-dependent-performance",
            "name": "Matrix-dependent performance",
            "description": "Connect peroxodisulfate consumption to the intended transformation in a specified medium.",
            "findings": [
              {
                "id": "effective-oxidant-use",
                "name": "Effective oxidant use",
                "description": "Require measurements of useful transformation, background demand, and residual oxidant.",
                "questions": [
                  {
                    "text": "How do pH, temperature, substrate composition, and competing matrix constituents affect measured consumption and outcome?",
                    "kind": "measurement",
                    "id": "effective-oxidant-use-q01"
                  },
                  {
                    "text": "Which validated performance and residual-oxidant criteria determine whether the material is suitable for the proposed application?",
                    "kind": "action",
                    "id": "effective-oxidant-use-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "handling-and-regulatory-applicability",
        "name": "Handling and regulatory applicability",
        "description": "Bind hazard evidence and action constraints to the exact peroxodisulfate-containing material.",
        "rationale": "The shared anion does not establish a universal SDS, exposure limit, transport classification, or disposal route.",
        "layers": [
          {
            "id": "material-specific-hazards",
            "name": "Material-specific hazards",
            "description": "Identify applicable classifications and exposure evidence.",
            "findings": [
              {
                "id": "hazard-record-match",
                "name": "Hazard record match",
                "description": "Verify that hazard records match the counterion, concentration, physical form, and jurisdiction.",
                "questions": [
                  {
                    "text": "Which current SDS and authoritative classification records cover this exact material and its oxidizing, irritation, or sensitization hazards?",
                    "kind": "provenance",
                    "id": "hazard-record-match-q01"
                  },
                  {
                    "text": "What exposure limits apply, if any, and are they expressed for a particular salt, persulfates as a group, or another measurement basis?",
                    "kind": "boundary",
                    "id": "hazard-record-match-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "compatibility-and-disposition",
            "name": "Compatibility and disposition",
            "description": "Translate applicable evidence into storage, use, and end-of-use decisions.",
            "findings": [
              {
                "id": "supported-handling-decisions",
                "name": "Supported handling decisions",
                "description": "Require documented compatibility and residual-oxidant criteria before selecting handling or disposal actions.",
                "questions": [
                  {
                    "text": "Which documented incompatibilities and storage limits apply to this salt or solution, including contamination and temperature constraints?",
                    "kind": "action",
                    "id": "supported-handling-decisions-q01"
                  },
                  {
                    "text": "What validated residual-peroxodisulfate assessment and local waste requirements govern treatment, transfer, or disposal?",
                    "kind": "action",
                    "id": "supported-handling-decisions-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "evidence-and-external-alignment",
        "name": "Evidence and external alignment",
        "description": "What the world already says about this thing, gathered so the model can be checked against it.",
        "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.",
        "layers": [
          {
            "id": "reported-evidence",
            "name": "Reported evidence",
            "description": "Findings from the breadth pass, kept separate from the structural claims.",
            "findings": [
              {
                "id": "evidence-confidence-notes",
                "name": "Check these first",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Confirm whether the registry intends the anion or the family of salts; the definition here centers on the anion.",
                  "CAS and EC identifiers, solubility, decomposition temperatures and hazard classifications must be assigned to a specified salt and formulation.",
                  "This is recalled knowledge; no sources were consulted."
                ],
                "questions": [
                  {
                    "id": "evidence-confidence-notes-q01",
                    "text": "Which of these check these first hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-kinds",
                "name": "Kinds and varieties",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Ammonium peroxodisulfate",
                  "Sodium peroxodisulfate",
                  "Potassium peroxodisulfate"
                ],
                "questions": [
                  {
                    "id": "evidence-kinds-q01",
                    "text": "Which of these kinds and varieties hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-identifiers",
                "name": "Identifiers and schemes",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "scheme": "Chemical formula",
                    "value_or_pattern": "S₂O₈²⁻",
                    "note": "Identifies the anion; individual salts have distinct formulas and substance identifiers."
                  },
                  {
                    "scheme": "Chemical nomenclature",
                    "value_or_pattern": "Peroxodisulfate; peroxydisulfate",
                    "note": "Persulfate is a common name, but its scope should be checked in commercial and process descriptions."
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-identifiers-q01",
                    "text": "Which of these identifiers and schemes hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-real-world-use",
                "name": "Real-world use",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Radical initiator in polymerization, commonly supplied as an ammonium, sodium or potassium salt.",
                  "Oxidant in chemical analysis and oxidative digestion.",
                  "Activated oxidant for treatment of contaminated water and soil.",
                  "Oxidizing ingredient in some hair-lightening formulations.",
                  "Oxidant in metal etching and surface treatment."
                ],
                "questions": [
                  {
                    "id": "evidence-real-world-use-q01",
                    "text": "Which of these real-world use hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-measurements",
                "name": "Typical measurements",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "quantity": "Molar mass of the anion",
                    "typical_range": "Approximately 192.12",
                    "unit": "g/mol"
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-measurements-q01",
                    "text": "Which of these typical measurements hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-failure-modes-and-hazards",
                "name": "Failure modes and hazards",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Peroxodisulfate salts are strong oxidizers and can intensify combustion of combustible materials.",
                  "Heat or incompatible contamination can promote decomposition, heat release and gas evolution.",
                  "Dust from some peroxodisulfate salts can cause respiratory sensitization and occupational asthma.",
                  "Contact with salts or concentrated solutions can irritate eyes and skin; some salts can cause skin sensitization.",
                  "Premature decomposition or reaction with other constituents can consume oxidant and reduce process effectiveness."
                ],
                "questions": [
                  {
                    "id": "evidence-failure-modes-and-hazards-q01",
                    "text": "Which of these failure modes and hazards hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-neighbours",
                "name": "Neighbouring kinds and how to tell them apart",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "name": "Peroxomonosulfate",
                    "difference": "Commonly encountered as HSO₅⁻, it contains one sulfur atom rather than the two in S₂O₈²⁻."
                  },
                  {
                    "name": "Sulfate",
                    "difference": "SO₄²⁻ lacks the peroxide O-O bond responsible for much of peroxodisulfate's oxidizing chemistry."
                  },
                  {
                    "name": "Peroxodisulfuric acid",
                    "difference": "H₂S₂O₈ is the parent acid; peroxodisulfate is its fully deprotonated dianion."
                  },
                  {
                    "name": "Sulfate radical anion",
                    "difference": "SO₄•⁻ is a reactive radical that can be generated by activating peroxodisulfate, rather than the starting dianion itself."
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-neighbours-q01",
                    "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of peroxodisulfate this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Does the originating registry evidence define peroxodisulfate as the dianion or as a collective name for its salts?",
    "Which identifiers are independently verified for the anion, and which must remain exclusively attached to individual salt models?",
    "Which analytical methods selectively quantify intact peroxodisulfate in the intended matrices, with what interferences and detection limits?",
    "Which stability and activation claims remain valid across the relevant counterions, concentrations, impurities, and environmental conditions?",
    "Which physical-property, hazard, exposure-limit, and disposal records apply to the specific materials the catalogue is expected to support?"
  ],
  "statistics": {
    "bundles": 6,
    "layers": 11,
    "findings": 17,
    "questions": 27
  }
}
