{
  "spore": "profile",
  "id": "ca",
  "spore_version": "0.2",
  "family": "engineering-polymers",
  "name": "Cellulose acetate",
  "abbreviation": "CA",
  "role": "bioplastic film base, eyeglass frame and fibre material",
  "category": "polymers",
  "type": "cellulosics",
  "summary": "Cellulose acetate (CA) is a cellulose ester made by acetylating wood pulp or cotton linters. The Eastman CA-398-3 grade read for this profile has an acetyl content of 39.8 wt %, a glass transition of 180 °C, and a specific gravity of 1.31. As a sample on the NASA MISSE 2 PEACE tray in low Earth orbit it had an atomic oxygen erosion yield of 5.05e-24 cm3/atom, close to the 5.06e-24 cm3/atom that the NASA predictive tool gave for it. The film base was once the standard for photographic film before polyester replaced it.\n",
  "best_for": "Stiff, clear film and moulding compound from a cellulose ester: a glass transition of 180 °C in the Eastman CA-398-3 grade, and a flight-measured erosion yield of 5.05e-24 cm3/atom in low Earth orbit for predicting similar esters",
  "weakest_at": "Heat and moisture: the Eastman SDS prints a decomposition temperature of 304 °C, sources say CA releases acetic acid when heat or moisture act on film, and it erodes in low Earth orbit at 5.05e-24 cm3/atom",
  "identity": {
    "formula": "Cellulose acetate, repeat unit C12H16O8 as printed in NASA TM-2008-215490 Table IV (a triacetate-type formula; the Eastman CA-398-3 grade is printed at 39.8 wt % acetyl)",
    "cas": "9004-35-7",
    "designations": [],
    "source": "eastman-sds-ca398-3",
    "where": "Section 3 (cellulose acetate, CAS-No. 9004-35-7, 100 % w/w); NASA TM-2008-215490 Table IV (formula C12H16O8, atomic mass 288.2536 g/mole)"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "uv",
      "thermal-cycling"
    ],
    "applications": [
      "optics-and-cameras",
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, MISSE 2 PEACE polymers table",
      "value": 1.2911,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "basis": "ref. 12 density measurement, as printed in NASA Table II"
      },
      "method": "Density measured for the MISSE 2 PEACE polymer set and listed in NASA TM-2008-215490 Table II; no test standard printed",
      "status": "ground",
      "source": "nasa-tm-2008-215490",
      "where": "Table II (MISSE 2 PEACE polymers density and fractional ash content), row Cellulose acetate, CA",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks, de Groh and Backus, 2008), NTRS 20090011780",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "NASA public document"
      }
    },
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Atomic oxygen erosion yield, cellulose acetate (MISSE 2)",
      "value": 5.05e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "platform": "ISS, MISSE 2 PEACE, low Earth orbit",
        "fluence": "8.43e21 atoms/cm2 over a 4 year exposure, as printed in the report text",
        "table": "Table I, MISSE 2 PEACE polymers erosion yield data"
      },
      "method": "Measured on MISSE 2 flight samples and listed in NASA TM-2008-215490, Table I",
      "status": "flight",
      "source": "nasa-tm-2008-215490",
      "where": "Table I (MISSE 2 PEACE polymers erosion yield data), row Cellulose acetate, CA; fluence in section 2 text",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks, de Groh and Backus, 2008), NTRS 20090011780",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "NASA public document"
      }
    },
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Atomic oxygen erosion yield, cellulose acetate (predicted)",
      "value": 5.06e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "basis": "NASA predictive tool, NASA TM-2008-215490"
      },
      "method": "Predicted by the NASA predictive tool and listed next to the MISSE 2 measured value",
      "status": "prediction",
      "source": "nasa-tm-2008-215490",
      "where": "Table VII (comparison of predicted and actual measured atomic oxygen erosion yields), row Cellulose acetate, CA",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks, de Groh and Backus, 2008), NTRS 20090011780",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "NASA public document"
      }
    },
    {
      "benchmark": "glass_transition_temperature",
      "label": "Glass transition temperature, Eastman CA-398-3",
      "value": 180,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3",
        "method_as_printed": "Glass Transition Temperature (Tg)"
      },
      "method": "Typical value printed on the manufacturer product data sheet; the sheet notes typical values for average lots",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, page 2, Glass Transition Temperature (Tg) row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "glass_transition_temperature",
      "label": "Glass transition temperature, Eastman CA-398-30",
      "value": 189,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-30",
        "method_as_printed": "Glass Transition Temperature (Tg)"
      },
      "method": "Typical value printed on the manufacturer product data sheet",
      "status": "ground",
      "source": "eastman-tds-ca398-30",
      "where": "Typical Properties table, Glass Transition Temperature (Tg) row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-30), product data sheet",
        "id": "Typical Properties table",
        "url": "https://www.chempoint.com/products/download?grade=3673&type=tds",
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Specific gravity, Eastman CA-398-3",
      "value": 1.31,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3",
        "basis": "specific gravity as printed (Wt/Vol 1.31 kg/L)"
      },
      "method": "Typical value printed on the manufacturer product data sheet",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, Specific Gravity row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Relative density, Eastman CA-398-10",
      "value": 1.31,
      "value_high": 1.32,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-10",
        "basis": "relative density as printed in the safety data sheet"
      },
      "method": "Printed in the manufacturer safety data sheet, physical and chemical properties block",
      "status": "ground",
      "source": "eastman-sds-ca398-10",
      "where": "Section 9, Relative density row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-10), safety data sheet",
        "id": "SDS version 225.1",
        "url": "https://www.chempoint.com/products/download?doctype=sds&grade=3671",
        "kind": "datasheet",
        "license": "supplier SDS, linked not reproduced"
      }
    },
    {
      "benchmark": "refractive_index",
      "label": "Refractive index, Eastman CA-398-3",
      "value": 1.475,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3"
      },
      "method": "Typical value printed on the manufacturer product data sheet; no temperature or wavelength printed",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, Refractive Index row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "dielectric_strength",
      "label": "Dielectric strength, Eastman CA-398-3",
      "value": 669,
      "bound": "exact",
      "unit": "kv/cm",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3",
        "minimum_as_printed": "1.7 kv/mil"
      },
      "method": "Typical value printed on the manufacturer product data sheet; no test standard printed",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, page 2, Dielectric Strength row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, Eastman CA-398-3 (data sheet)",
      "value": 230,
      "value_high": 250,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3"
      },
      "method": "Typical value printed on the manufacturer product data sheet; the 2016 to 2018 SDS for the same grade prints melting point as not determined",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, Melting Point row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "decomposition_temperature",
      "label": "Decomposition temperature, Eastman CA-398-3",
      "value": 304,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3",
        "printed_as": "579 °F / 304 °C"
      },
      "method": "Printed in the manufacturer safety data sheet, physical and chemical properties section; no method printed for the temperature",
      "status": "ground",
      "source": "eastman-sds-ca398-3",
      "where": "Physical and chemical properties section, Decomposition temperature row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), safety data sheet",
        "id": "SDS version 2.1, revision 06/14/2018, SDS number 150000001217",
        "url": "https://www.chempoint.com/products/download?grade=3672&type=msds",
        "year": 2018,
        "kind": "datasheet",
        "license": "supplier SDS, linked not reproduced"
      }
    },
    {
      "benchmark": "decomposition_energy",
      "label": "Decomposition energy, Eastman CA-398-3",
      "value": 123,
      "bound": "exact",
      "unit": "J/g",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3"
      },
      "method": "DSC, as printed in the manufacturer safety data sheet, section 9",
      "status": "ground",
      "source": "eastman-sds-ca398-3",
      "where": "Section 9, Decomposition energy (mass) row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), safety data sheet",
        "id": "SDS version 2.1, revision 06/14/2018, SDS number 150000001217",
        "url": "https://www.chempoint.com/products/download?grade=3672&type=msds",
        "year": 2018,
        "kind": "datasheet",
        "license": "supplier SDS, linked not reproduced"
      }
    },
    {
      "benchmark": "acetyl_content",
      "label": "Acetyl content, Eastman CA-398-3",
      "value": 39.8,
      "bound": "exact",
      "unit": "wt %",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3"
      },
      "method": "Typical value printed on the manufacturer product data sheet",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, Acetyl Content row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    },
    {
      "benchmark": "hydroxyl_content",
      "label": "Hydroxyl content, Eastman CA-398-3",
      "value": 3.5,
      "bound": "exact",
      "unit": "wt %",
      "scope": "material",
      "conditions": {
        "grade": "Eastman Cellulose Acetate CA-398-3"
      },
      "method": "Typical value printed on the manufacturer product data sheet",
      "status": "ground",
      "source": "eastman-tds-ca398-3",
      "where": "Typical Properties table, Hydroxyl Content row",
      "source_detail": {
        "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
        "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
        "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
        "year": 2008,
        "kind": "datasheet",
        "license": "manufacturer data sheet, linked not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Low Earth orbit, atomic oxygen",
      "headline": "CA erodes at 5.05e-24 cm3/atom on MISSE 2, about 1.9 times the PP value on the same tray.",
      "effect": "NASA lists the flight erosion yield of cellulose acetate as 5.05e-24 cm3/atom after an 8.43e21 atoms/cm2 fluence over four years, against 2.68e-24 cm3/atom for polypropylene on the same experiment.",
      "rating": "unknown",
      "conditions": {
        "basis": "flight samples on the ISS, MISSE 2 PEACE tray, 4 year exposure",
        "reference": "NASA TM-2008-215490, Table I"
      },
      "source": "nasa-tm-2008-215490",
      "where": "Table I, row Cellulose acetate, CA"
    },
    {
      "environment": "Ultraviolet light, accelerated weathering",
      "headline": "The 2023 weathering study found that cellulose acetate is less UV stable than PLA, and that UV light changes its colour.",
      "effect": "Mušič et al. 2023 weathered cigarette-filter CA with a xenon arc lamp and report that PLA was more stable than CA under UV light, with colour change used as the measure. The paper gives no retention figure for CA tensile strength or elongation.",
      "rating": "unknown",
      "conditions": {
        "basis": "xenon arc lamp, ground microplastic powder from used cigarette filters, not a service test",
        "reference": "Mušič et al. 2023, Abstract and Section 2.2"
      },
      "source": "mdpi-cigarette-ca-2023",
      "where": "Abstract, final sentence; Section 2.2"
    },
    {
      "environment": "Ultraviolet light below 280 nm",
      "headline": "Photodegradation is fastest at 280 nm or shorter and is enhanced by TiO2 pigment.",
      "effect": "Wikipedia states that photodegradation of cellulose acetate is optimal with 280 nm or shorter UV irradiation and is enhanced by TiO2 pigment, and that CA cigarette filters take years to break down in the open.",
      "rating": "unknown",
      "conditions": {
        "basis": "general statement, no test condition given in the source"
      },
      "source": "wikipedia-cellulose-acetate",
      "where": "Disposal and degradation section"
    },
    {
      "environment": "Heat or moisture on film",
      "headline": "Acid in cellulose acetate film releases acetic acid when heat or moisture act on it, a process called vinegar syndrome.",
      "effect": "Wikipedia states that, when exposed to heat or moisture, acids in the film base begin to deteriorate the film, releasing acetic acid with a vinegary smell. The page gives no temperature or humidity threshold.",
      "rating": "unknown",
      "conditions": {
        "basis": "general statement about cellulose acetate film stock, no test condition given"
      },
      "source": "wikipedia-cellulose-acetate",
      "where": "Film section"
    },
    {
      "environment": "Strong alkali and strong oxidizing agents",
      "headline": "Strong alkaline solutions and strong oxidizers weaken CA, and the Eastman SDS lists strong oxidizing agents as incompatible.",
      "effect": "Wikipedia states that cellulose acetate is easily weakened by strong alkaline solutions and strong oxidizing agents. The Eastman SDS lists strong oxidizing agents as incompatible materials and carbon monoxide and carbon dioxide as hazardous decomposition products.",
      "rating": "unknown",
      "conditions": {
        "basis": "general statement from Wikipedia; SDS incompatibility list for the CA-398-3 grade"
      },
      "source": "eastman-sds-ca398-3",
      "where": "Section 10, Incompatible materials and Hazardous decomposition products rows"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "GHS classification is Combustible dust, with the signal word Warning and the statement May form combustible dust concentrations in air. Flash point is printed as not applicable, combustible solid.",
        "ghs": [],
        "source": "eastman-sds-ca398-3",
        "where": "Sections 2 and 9"
      },
      {
        "text": "The dust explosion class is printed as St 2, strong explosion. The SDS says fine dust dispersed in air with an ignition source is a potential dust explosion hazard.",
        "ghs": [],
        "source": "eastman-sds-ca398-3",
        "where": "Fire-fighting measures section and physical and chemical properties section (dust explosion class row)"
      },
      {
        "text": "Carcinogenicity: no ingredient at 0.1 % or more is listed by IARC, OSHA or NTP for the CA-398-10 grade.",
        "ghs": [],
        "source": "eastman-sds-ca398-10",
        "where": "Regulatory information section (IARC, OSHA and NTP rows)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Atomic oxygen erosion in low Earth orbit",
        "trigger": "Exposure of a cellulose acetate part to atomic oxygen in low Earth orbit, as on the MISSE 2 flight",
        "consequence": "Surface erosion at a yield of 5.05e-24 cm3/atom as measured on MISSE 2, with 5.06e-24 cm3/atom predicted by NASA.",
        "severity": "moderate",
        "source": "nasa-tm-2008-215490",
        "where": "Table I and Table VII"
      },
      {
        "mode": "Acid release under heat or moisture",
        "trigger": "Heat or moisture acting on cellulose acetate film base",
        "consequence": "The film deteriorates and releases acetic acid, with a vinegar smell (vinegar syndrome). Wikipedia notes this was the failure mode of historic acetate film stock.",
        "severity": "moderate",
        "source": "wikipedia-cellulose-acetate",
        "where": "Film section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Minimise dust generation and accumulation, and keep ignition sources away from dust clouds, since the SDS classes the dust as St 2.",
        "source": "eastman-sds-ca398-3"
      },
      {
        "text": "The grade is a solid powder or flake with a negligible water solubility; the SDS prints no hazard classification beyond combustible dust.",
        "source": "eastman-sds-ca398-3"
      },
      {
        "text": "The SDS documents read here are dated 2016 to 2018, so check the current supplier SDS for the grade before handling.",
        "source": "eastman-sds-ca398-3"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "optics-and-cameras",
      "device": "Photographic and motion-picture film base",
      "example": "Cellulose acetate film replaced cellulose nitrate film for photographic use in the 1950s, being far less flammable and cheaper to produce, according to Wikipedia.",
      "source": "wikipedia-cellulose-acetate",
      "where": "Film section"
    },
    {
      "application": "electronics-and-chips",
      "device": "Polymer sample on a space flight experiment",
      "example": "Cellulose acetate on the MISSE 2 PEACE tray, flown on the ISS in low Earth orbit, with its erosion yield listed in NASA TM-2008-215490.",
      "source": "nasa-tm-2008-215490",
      "where": "Table I"
    }
  ],
  "supply": [
    {
      "subject": "Cellulose acetate (global output)",
      "abundance": "Producers named in the article: Celanese and Eastman Chemical Company in the US, and DP Acetate in the EU for filament yarn. No country shares were read.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wikipedia-cellulose-acetate",
      "where": "Production section and Disposal and degradation section"
    },
    {
      "subject": "Cellulose feedstock",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wikipedia-cellulose-acetate",
      "where": "Characteristics list and Production section"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
      "type": "datasheet",
      "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
      "year": 2008
    },
    {
      "title": "Eastman Cellulose Acetate (CA-398-30), product data sheet",
      "type": "datasheet",
      "url": "https://www.chempoint.com/products/download?grade=3673&type=tds"
    },
    {
      "title": "Eastman Cellulose Acetate (CA-398-3), safety data sheet, version 2.1",
      "type": "sds",
      "url": "https://www.chempoint.com/products/download?grade=3672&type=msds",
      "year": 2018
    },
    {
      "title": "Eastman Cellulose Acetate (CA-398-10), safety data sheet, version 225.1",
      "type": "sds",
      "url": "https://www.chempoint.com/products/download?doctype=sds&grade=3671"
    },
    {
      "title": "Banks, de Groh and Backus, Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit, NASA/TM-2008-215490",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008
    },
    {
      "title": "Mušič, Jemec Kokalj and Sever Škapin, Influence of Weathering on the Degradation of Cellulose Acetate Microplastics Obtained from Used Cigarette Butts, Polymers 15(12), 2751",
      "type": "paper",
      "url": "https://www.mdpi.com/2073-4360/15/12/2751",
      "year": 2023
    },
    {
      "title": "NIST Atomic Weights and Isotopic Compositions for All Elements (H, C and O rows)",
      "type": "database",
      "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=O&all=all&ascii=html"
    }
  ],
  "gaps": [
    "Tensile strength, elongation and modulus of Eastman CA-398-3 or CA-398-30 were not printed on the sources read. The datasheets say the full mechanical data sit behind an account.",
    "Heat deflection temperature, Vicat softening temperature and maximum service temperature for CA were not read on a fetched page in this run.",
    "Melting point is printed as 230 to 250 °C on the Eastman data sheet but as not determined in the SDSs read; the conflict is recorded, not resolved.",
    "UV ageing numbers for CA (retention of tensile strength or elongation after a dose) were not read; the 2023 paper reports colour change and particle size only.",
    "Outgassing, total mass loss, radiation and vacuum data for cellulose acetate in space were not read in this run, beyond the erosion yield.",
    "Chemical resistance to solvents, water absorption and moisture uptake values were not read on a fetched page in this run.",
    "Supply by country share and current producer tonnages were not found on a primary source; the 800,000 tonnes figure is a 2008 value cited without a source.",
    "Critical-mineral status is not applicable to a cellulose ester, so no USGS or EU list entry was added.",
    "Decomposition temperature, decomposition energy, acetyl content and hydroxyl content are not in the canonical property file, so their snake_case names are used as printed; the canonical list may need them.",
    "The PubChem record for cellulose acetate returned no data in this run, so no PubChem GHS entry is recorded.",
    "The formula printed by NASA (C12H16O8) is a triacetate-type repeat unit, while Wikipedia calls the common form diacetate; the grade data (39.8 wt % acetyl) sit between the two."
  ],
  "story": {
    "why": "Cellulose acetate is a stiff, clear cellulose ester with a glass transition of 180 °C in the Eastman CA-398-3 grade and a density of 1.31 g/cm3 on the data sheet. The NASA report gives a density of 1.2911 g/cm3 for the MISSE 2 sample. Its flight erosion yield of 5.05e-24 cm3/atom is the reference value for the ester in low Earth orbit.",
    "uses": [
      {
        "where": "Use",
        "line": "Photographic and motion-picture film base, which replaced nitrate film in the 1950s (Wikipedia)."
      },
      {
        "where": "Use",
        "line": "Eyeglass frames, fibres for fabrics and cigarette filters (Wikipedia)."
      },
      {
        "where": "Use",
        "line": "Coatings and plastics with plasticisers, as the Eastman data sheet lists for CA-398-3 (coatings for glass and paper, food-contact films, electrical uses)."
      }
    ],
    "can_do": [
      {
        "label": "Stiff and clear at room temperature",
        "line": "The Eastman CA-398-3 data sheet prints a glass transition of 180 °C and a refractive index of 1.475.",
        "benchmark": "glass_transition_temperature",
        "scope": "material",
        "value": "180 °C glass transition"
      },
      {
        "label": "Insulate",
        "line": "The same data sheet prints a dielectric strength of 669 kv/cm (1.7 kv/mil), as a typical value without a test standard.",
        "benchmark": "dielectric_strength",
        "scope": "material",
        "value": "669 kv/cm dielectric strength"
      },
      {
        "label": "Survive in orbit",
        "line": "NASA lists a MISSE 2 erosion yield for cellulose acetate of 5.05e-24 cm3/atom, and predicts 5.06e-24 cm3/atom in Table VII.",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material",
        "value": "5.05e-24 cm3/atom"
      }
    ],
    "compare": "The grades and test methods differ between the sources, so the rows show each property as its own example, not a ranking. The Eastman CA-398-3 glass transition of 180 °C and CA-398-30 value of 189 °C are two grades of the same ester.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Erosion yield",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material"
      },
      {
        "label": "Glass transition",
        "benchmark": "glass_transition_temperature",
        "scope": "material"
      }
    ],
    "handling": [
      "Specify the grade, since acetyl content, viscosity and glass transition change with the grade (CA-398-3 and CA-398-30 differ).",
      "Control dust in the work area and keep ignition sources away from dust clouds, as the SDS directs.",
      "Keep the material away from strong oxidisers and strong alkaline solutions, as the SDS and Wikipedia state."
    ],
    "good_for": [
      "Clear film base and coating grades: a glass transition of 180 °C and a refractive index of 1.475 for the Eastman CA-398-3 grade.",
      "Known atomic oxygen behaviour: 5.05e-24 cm3/atom on MISSE 2 in low Earth orbit, measured on a flight sample.",
      "Dielectric use at a printed 669 kv/cm (typical), for the same grade."
    ],
    "watch_out": [
      "Heat and moisture: the SDS prints a decomposition temperature of 304 °C, and sources say acetic acid is released from film under heat or moisture.",
      "Atomic oxygen: the flight erosion yield of 5.05e-24 cm3/atom is about 1.9 times the 2.68e-24 cm3/atom measured for polypropylene on the same tray.",
      "Melting point: the Eastman data sheet prints 230 to 250 °C, while the SDS prints not determined, so do not treat the melting range as settled.",
      "No tensile, outgassing or UV retention data for CA were found in this run."
    ],
    "verdict": "Cellulose acetate is a stiff cellulose ester with a glass transition of 180 °C in the Eastman CA-398-3 grade and a MISSE 2 erosion yield of 5.05e-24 cm3/atom in low Earth orbit. It is a combustible dust, and it degrades under heat, moisture and UV. This profile has no sourced tensile, outgassing or UV retention values.",
    "recipe": {
      "line": "Cellulose acetate is made by acetylating cellulose, a glucose polymer with three hydroxyls per anhydroglucose unit, with acetic acid and acetic anhydride under a sulfuric acid catalyst, then partially hydrolysing the triacetate to a lower acetyl content. The repeat unit printed by NASA is C12H16O8.",
      "parts": [
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Twelve carbons per repeat unit, in the glucose ring and the acetyl groups.",
          "share_note": "atomic_weight [12.0096, 12.0116]"
        },
        {
          "name": "Hydrogen",
          "symbol": "H",
          "role": "Sixteen hydrogens per repeat unit, on the ring and in the acetyl methyl groups.",
          "share_note": "atomic_weight [1.007 84, 1.008 11]"
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Eight oxygens per repeat unit, in the ring and the ester groups.",
          "share_note": "atomic_weight [15.999 03, 15.999 77]"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The SDS pages read here classify cellulose acetate by its dust, not by a toxic hazard.",
        "points": [
          {
            "label": "Classification",
            "line": "The Eastman SDSs print the GHS classification as combustible dust with the warning Warning, and no acute toxicity classification is printed."
          },
          {
            "label": "Dust",
            "line": "The dust explosion class is printed as St 2, strong explosion, so fine dust needs the same care as other combustible dusts."
          }
        ],
        "level": 1,
        "verdict": "Combustible dust, no toxic classification"
      },
      {
        "title": "If it fails",
        "lead": "The failure routes in these sources are erosion in orbit and acid release from film under heat or moisture.",
        "points": [
          {
            "label": "Atomic oxygen",
            "line": "On MISSE 2 the erosion yield was 5.05e-24 cm3/atom, against 5.06e-24 cm3/atom predicted by NASA."
          },
          {
            "label": "Heat and moisture",
            "line": "Wikipedia describes acetic acid release from film exposed to heat or moisture, which is the vinegar syndrome of historic film stock."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-20",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 14,
    "unreachable": 2,
    "caveats": 4,
    "note": "Values were read by an AI assistant on 2026-10-20 from the pages named in each entry. NASA Table I, II, IV and VII were read from the text of the NTRS PDF. Eastman datasheets and SDSs were read from the ChemPoint PDF downloads. Unreachable: the PubChem cellulose acetate record (no data returned) and the ULprospector CA-398-3 page (blocked by a bot check). Caveats: the Eastman CA-398-3 melting point conflicts with its SDS; the NASA formula is a triacetate-type repeat unit; the erosion yield is a single flight sample; the 2023 UV study is on cigarette-filter powder, not film."
  },
  "sources": {
    "nasa-tm-2008-215490": {
      "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
      "id": "NASA/TM-2008-215490 (Banks, de Groh and Backus, 2008), NTRS 20090011780",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008,
      "kind": "report",
      "license": "NASA public document"
    },
    "eastman-tds-ca398-3": {
      "title": "Eastman Cellulose Acetate (CA-398-3), product data sheet",
      "id": "Typical Properties table, printed 6/19/2008 from eastman.com",
      "url": "https://www.chempoint.com/products/download?grade=3672&doctype=tds&documentid=0103000199393021445228&language=English",
      "year": 2008,
      "kind": "datasheet",
      "license": "manufacturer data sheet, linked not reproduced"
    },
    "eastman-tds-ca398-30": {
      "title": "Eastman Cellulose Acetate (CA-398-30), product data sheet",
      "id": "Typical Properties table",
      "url": "https://www.chempoint.com/products/download?grade=3673&type=tds",
      "kind": "datasheet",
      "license": "manufacturer data sheet, linked not reproduced"
    },
    "eastman-sds-ca398-3": {
      "title": "Eastman Cellulose Acetate (CA-398-3), safety data sheet",
      "id": "SDS version 2.1, revision 06/14/2018, SDS number 150000001217",
      "url": "https://www.chempoint.com/products/download?grade=3672&type=msds",
      "year": 2018,
      "kind": "datasheet",
      "license": "supplier SDS, linked not reproduced"
    },
    "eastman-sds-ca398-10": {
      "title": "Eastman Cellulose Acetate (CA-398-10), safety data sheet",
      "id": "SDS version 225.1",
      "url": "https://www.chempoint.com/products/download?doctype=sds&grade=3671",
      "kind": "datasheet",
      "license": "supplier SDS, linked not reproduced"
    },
    "mdpi-cigarette-ca-2023": {
      "title": "Influence of Weathering on the Degradation of Cellulose Acetate Microplastics Obtained from Used Cigarette Butts",
      "id": "Mušič, Jemec Kokalj and Sever Škapin, Polymers 15(12), 2751, doi 10.3390/polym15122751",
      "url": "https://www.mdpi.com/2073-4360/15/12/2751",
      "year": 2023,
      "kind": "paper",
      "license": "open access article, linked not reproduced"
    },
    "wikipedia-cellulose-acetate": {
      "title": "Cellulose acetate, Wikipedia",
      "id": "Cellulose acetate article, Film, Production, Disposal and degradation sections",
      "url": "https://en.wikipedia.org/wiki/Cellulose_acetate",
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "nist-atomic-weights": {
      "title": "NIST Atomic Weights and Isotopic Compositions for All Elements (H, C and O rows)",
      "id": "NIST standard atomic weight table: C [12.0096, 12.0116]; H [1.007 84, 1.008 11]; O [15.999 03, 15.999 77]",
      "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=O&all=all&ascii=html",
      "kind": "database",
      "license": "US government data"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/ca/"
}