{
  "spore": "profile",
  "id": "csm-hypalon",
  "spore_version": "0.2",
  "family": "chlorosulfonated-polyethylene",
  "name": "Chlorosulfonated polyethylene (CSM, Hypalon)",
  "abbreviation": "CSM",
  "role": "elastomer",
  "category": "seals-adhesives",
  "type": "elastomers-and-o-rings",
  "summary": "Chlorosulfonated polyethylene (CSM) is a synthetic rubber made by treating polyethylene with chlorine and sulfur dioxide under UV light. DuPont sold it as Hypalon. One compound datasheet from Angst+Pfister gives a density of 1.48 g/cm³, a tensile strength of 8.00 N/mm² and an elongation at break of 300 %, with an operating range from -30 °C to 120 °C. NASA's ground outgassing table records a Hypalon cable insulation with 9.13 % total mass loss, far above the screening limits that the report describes.\n",
  "best_for": "Weather, ozone and chemical resistance in flexible rubber parts (family guide and compound datasheets rate ozone, sunlight and weather resistance as Excellent)",
  "weakest_at": "Vacuum outgassing: the Hypalon cable insulation in NASA's table lost 9.13 % of its mass, and the sources found no grade that passes the screen in that row",
  "identity": {
    "formula": "Polyethylene chain carrying chlorine atoms and chlorosulfonyl (-SO2Cl) groups; repeat unit -[CH2-CH(Cl)]x-[CH2-CH(SO2Cl)]y- (Wikipedia)",
    "designations": [
      {
        "system": "Trade name",
        "code": "Hypalon",
        "source": "wiki-hypalon",
        "where": "Lead section, first sentence"
      }
    ],
    "source": "wiki-hypalon",
    "where": "Chemical structure and Synthesis sections"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "vacuum-and-outgassing"
    ],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, CSM compound 70.98-01",
      "value": 1.48,
      "bound": "exact",
      "unit": "g/cm³",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01, black (Angst+Pfister)",
        "test_method": "not named in the datasheet",
        "temperature": "not stated"
      },
      "method": "Value printed in a compound datasheet, which says values are not guaranteed property values",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Mechanical properties block, row Density",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "hardness_shore_a",
      "label": "Hardness, CSM compound 70.98-01",
      "value": 70,
      "bound": "exact",
      "unit": "Shore A",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01 (Angst+Pfister)",
        "tolerance": "printed as plus or minus 5",
        "test_standard": "DIN ISO 7619-1"
      },
      "method": "Nominal value printed in a compound datasheet",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Mechanical properties block, row Hardness nominal",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "hardness_shore_a",
      "label": "Hardness, CSM75 black compound",
      "value": 75,
      "bound": "exact",
      "unit": "ShA",
      "scope": "material",
      "conditions": {
        "compound": "CSM75 black (Polymax)",
        "value_type": "typical value (column header)"
      },
      "method": "Typical value printed in a supplier datasheet",
      "status": "ground",
      "source": "polymax-csm75",
      "where": "Physical property table, row Hardness, column Typical Values",
      "source_detail": {
        "title": "CSM (Hypalon) Black 75 ShA, product CSM75 (Polymax)",
        "url": "https://m2dev.polymax.co.uk/media/documents/Datasheet/oring/CSM75-CSM_Hypalon_Black_75_ShA.pdf",
        "kind": "datasheet",
        "license": "Supplier datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, CSM compound 70.98-01",
      "value": 8,
      "bound": "exact",
      "unit": "N/mm²",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01 (Angst+Pfister)",
        "test_standard": "DIN 53504",
        "temperature": "not stated"
      },
      "method": "Value printed in a compound datasheet",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Mechanical properties block, row Tensile strength",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break, CSM compound 70.98-01",
      "value": 300,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01 (Angst+Pfister)",
        "test_standard": "DIN 53504"
      },
      "method": "Value printed in a compound datasheet",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Mechanical properties block, row Elongation at break",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Minimum operating temperature, CSM compound 70.98-01",
      "value": -30,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01 (Angst+Pfister)",
        "basis": "printed as approximate, dependent on the application"
      },
      "method": "Value printed in a compound datasheet",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Thermal properties block, row Operating temperature min.",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum operating temperature, CSM compound 70.98-01",
      "value": 120,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "compound": "CSM 70.98-01 (Angst+Pfister)",
        "basis": "printed as approximate, dependent on the application"
      },
      "method": "Value printed in a compound datasheet",
      "status": "ground",
      "source": "angst-csm70",
      "where": "Thermal properties block, row Operating temperature max.",
      "source_detail": {
        "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
        "id": "compound code CSM 70.98-01",
        "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Low end of operating temperature range, CSM75",
      "value": -35,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "compound": "CSM75 black (Polymax)",
        "form": "range as printed in the header block"
      },
      "method": "Range printed in a supplier datasheet",
      "status": "ground",
      "source": "polymax-csm75",
      "where": "Header block, line Operating Temperature range",
      "source_detail": {
        "title": "CSM (Hypalon) Black 75 ShA, product CSM75 (Polymax)",
        "url": "https://m2dev.polymax.co.uk/media/documents/Datasheet/oring/CSM75-CSM_Hypalon_Black_75_ShA.pdf",
        "kind": "datasheet",
        "license": "Supplier datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "High end of operating temperature range, CSM75",
      "value": 125,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "compound": "CSM75 black (Polymax)",
        "form": "range as printed in the header block"
      },
      "method": "Range printed in a supplier datasheet",
      "status": "ground",
      "source": "polymax-csm75",
      "where": "Header block, line Operating Temperature range",
      "source_detail": {
        "title": "CSM (Hypalon) Black 75 ShA, product CSM75 (Polymax)",
        "url": "https://m2dev.polymax.co.uk/media/documents/Datasheet/oring/CSM75-CSM_Hypalon_Black_75_ShA.pdf",
        "kind": "datasheet",
        "license": "Supplier datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss, Okonite I/C 6-61 cable insulation (DuPont Hypalon)",
      "value": 9.13,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "cable insulation, Okonite I/C 6-61, Hypalon by DuPont",
        "data_reference": "GSFC3604",
        "cure": "blank in the row",
        "test": "GSFC outgassing test in vacuum, as described in the NASA report"
      },
      "method": "Value printed in the NASA GSFC outgassing compilation",
      "status": "ground",
      "source": "nasa-rp1124",
      "where": "Materials table, row CABLE I/C 6-61 BY OKONITE, DuPont HYPALON, GSFC3604, %TML column",
      "source_detail": {
        "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
        "id": "NTRS 19940017416",
        "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
        "year": 1993,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "collected_volatile_condensable_material",
      "label": "Collected volatile condensable material, same cable row",
      "value": 4.52,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "cable insulation, Okonite I/C 6-61, Hypalon by DuPont",
        "data_reference": "GSFC3604",
        "cure": "blank in the row",
        "test": "GSFC outgassing test in vacuum"
      },
      "method": "Value printed in the NASA GSFC outgassing compilation",
      "status": "ground",
      "source": "nasa-rp1124",
      "where": "Materials table, row CABLE I/C 6-61 BY OKONITE, DuPont HYPALON, GSFC3604, %CVCM column",
      "source_detail": {
        "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
        "id": "NTRS 19940017416",
        "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
        "year": 1993,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss, Coverlite H fabric (Hypalon-coated nylon)",
      "value": 0.98,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "COVERLITE H FABRIC 55-61811-XX, Hypalon coated nylon",
        "data_reference": "GSFC8399",
        "cure_time": "72H as printed",
        "cure_temperature": "125 as printed (unit not given in the table legend)",
        "atmosphere": "E-2 as printed"
      },
      "method": "Value printed in the NASA GSFC outgassing compilation",
      "status": "ground",
      "source": "nasa-rp1124",
      "where": "Materials table, row COVERLITE H FABRIC, GSFC8399, %TML column",
      "source_detail": {
        "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
        "id": "NTRS 19940017416",
        "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
        "year": 1993,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "collected_volatile_condensable_material",
      "label": "Collected volatile condensable material, Coverlite H fabric",
      "value": 0.02,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "COVERLITE H FABRIC 55-61811-XX, Hypalon coated nylon",
        "data_reference": "GSFC8399",
        "cure_time": "72H as printed",
        "cure_temperature": "125 as printed (unit not given in the table legend)",
        "atmosphere": "E-2 as printed"
      },
      "method": "Value printed in the NASA GSFC outgassing compilation",
      "status": "ground",
      "source": "nasa-rp1124",
      "where": "Materials table, row COVERLITE H FABRIC, GSFC8399, %CVCM column",
      "source_detail": {
        "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
        "id": "NTRS 19940017416",
        "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
        "year": 1993,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "water_vapor_regained",
      "label": "Water vapor regained, Coverlite H fabric",
      "value": 0.8,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "COVERLITE H FABRIC 55-61811-XX, Hypalon coated nylon",
        "data_reference": "GSFC8399",
        "cure_time": "72H as printed",
        "cure_temperature": "125 as printed (unit not given in the table legend)",
        "atmosphere": "E-2 as printed"
      },
      "method": "Value printed in the NASA GSFC outgassing compilation",
      "status": "ground",
      "source": "nasa-rp1124",
      "where": "Materials table, row COVERLITE H FABRIC, GSFC8399, %WVR column",
      "source_detail": {
        "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
        "id": "NTRS 19940017416",
        "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
        "year": 1993,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "chlorine_content",
      "label": "Chlorine content, general description of the polymer",
      "value": 20,
      "value_high": 40,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "stated for the product as a whole, by weight"
      },
      "method": "Range stated in the encyclopedia entry (sentence on synthesis)",
      "status": "ground",
      "note": "The same page gives 20 to 45 % for commercial grades, and GreenSpec gives 27 to 45 %; the sources disagree.",
      "source": "wiki-hypalon",
      "where": "Synthesis section, sentence beginning 'The product contains'",
      "source_detail": {
        "title": "Hypalon (encyclopedia entry; the URL given is a redirect from Chlorosulfonated polyethylene)",
        "url": "https://en.wikipedia.org/wiki/Chlorosulfonated_polyethylene",
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "chlorine_content",
      "label": "Chlorine content, commercial grades (Mark, Polymer Data Handbook)",
      "value": 20,
      "value_high": 45,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "commercial grades, by weight"
      },
      "method": "Range stated in the encyclopedia entry, citing Mark (Polymer Data Handbook)",
      "status": "ground",
      "note": "Disagrees with the 20 to 40 % range given earlier on the same page.",
      "source": "wiki-hypalon",
      "where": "Synthesis section, paragraph beginning 'Commercial grades typically contain'",
      "source_detail": {
        "title": "Hypalon (encyclopedia entry; the URL given is a redirect from Chlorosulfonated polyethylene)",
        "url": "https://en.wikipedia.org/wiki/Chlorosulfonated_polyethylene",
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "chlorine_content",
      "label": "Chlorine content, GreenSpec description",
      "value": 27,
      "value_high": 45,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "stated under the heading What is Chlorosulfonated polyethylene"
      },
      "method": "Range stated on a building-materials information page",
      "status": "ground",
      "note": "A third range; see the two Wikipedia ranges above.",
      "source": "greenspec-cspe",
      "where": "What is Chlorosulfonated polyethylene section",
      "source_detail": {
        "title": "Chlorosulfonated polyethylene (CSPE): environment and health (GreenSpec)",
        "url": "https://greenspec.co.uk/building-design/chlorosulfonated-polyethylene-cspe-environment-and-health/",
        "kind": "web",
        "license": "Web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "sulfur_content",
      "label": "Sulfur content, commercial grades (Mark, Polymer Data Handbook)",
      "value": 1,
      "value_high": 2,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "commercial grades, by weight"
      },
      "method": "Range stated in the encyclopedia entry, citing Mark (Polymer Data Handbook)",
      "status": "ground",
      "source": "wiki-hypalon",
      "where": "Synthesis section, paragraph beginning 'Commercial grades typically contain'",
      "source_detail": {
        "title": "Hypalon (encyclopedia entry; the URL given is a redirect from Chlorosulfonated polyethylene)",
        "url": "https://en.wikipedia.org/wiki/Chlorosulfonated_polyethylene",
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Sunlight, ozone and weather (outdoor exposure)",
      "headline": "CSM resists ozone, sunlight and weather well, according to the family guide and two compound datasheets.",
      "effect": "The Robinson Rubber family guide rates ozone, sunlight and weather resistance as Excellent. Angst+Pfister describes compound 70.98-01 as having good resistance against UV and ozone. Polymax says CSM75 resists ozone, aging and weathering. No numeric UV or ozone test result, and no exposure time, was found in the sources read.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative ratings in a family guide and two datasheets; no exposure time or test standard stated"
      },
      "source": "rrpc-csm",
      "where": "Environmental Performance table (Ozone, Sunlight and Weather rows); Angst+Pfister datasheet description; Polymax header description"
    },
    {
      "environment": "Incompatible fluids and solvents",
      "headline": "Aromatic and chlorinated solvents and polar fluids attack CSM75, according to its datasheet.",
      "effect": "Polymax lists propane, butane, aliphatic oils, polar solvents, phosphate-ester fluids, aromatic hydrocarbons and chlorinated hydrocarbons as not compatible with CSM75. The Robinson Rubber guide rates ketones, halogenated solvents, aromatic petroleum and diester oils as Poor. The two sources disagree on aliphatic oils and fuels: the Robinson guide rates aliphatic hydrocarbon fuel Fair to Good and mineral oils Good to Very Good.",
      "rating": "moderate",
      "conditions": {
        "basis": "compatibility list in a supplier datasheet and ratings in a family guide; no immersion test or swelling figure stated"
      },
      "source": "polymax-csm75",
      "where": "Opening description paragraph (incompatibility list); Robinson Rubber Chemical Resistance table"
    },
    {
      "environment": "Acids, alkalis and oxidising media",
      "headline": "Acids and alkalis are rated from good to excellent, according to the family guide and the CSM75 datasheet.",
      "effect": "The Robinson Rubber guide rates dilute acids Excellent, concentrated acids Good to Excellent, and dilute and concentrated alkalies Good to Excellent. Polymax says CSM75 resists many acids and oxidising media.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative ratings; concentrations and temperatures not stated in the sources read"
      },
      "source": "rrpc-csm",
      "where": "Chemical Resistance table, Acids and Alkalies rows"
    },
    {
      "environment": "Heat ageing in service",
      "headline": "No heat-ageing test result was found in the sources read.",
      "effect": "The sources give maximum service temperatures (see properties) but no time-at-temperature test and no property-retention result for any CSM compound.",
      "rating": "unknown",
      "conditions": {
        "basis": "not found in the sources read"
      },
      "source": "angst-csm70",
      "where": "Thermal properties block, operating temperature max. (stated as approximate)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "The 2021 safety data sheet for 2990 HYPALON Adhesive, a solvent adhesive that contains a Hypalon name and is not the bare polymer, gives the signal word Danger and classes the mixture as a highly flammable liquid and vapour, a skin and eye irritant, a possible skin sensitiser, a cause of drowsiness or dizziness, and toxic to aquatic life. Butanone is the listed ingredient in the composition table; cyclohexane and acetone are named in the Contains line.",
        "ghs": [
          "H225",
          "H315",
          "H317",
          "H319",
          "H336",
          "H411"
        ],
        "source": "sds-2990-rev",
        "where": "Section 2.1 (classification) and Section 2 signal word and hazard statements; Section 3.2 (Mixtures table)"
      },
      {
        "text": "The older 2008 safety data sheet for the same adhesive gives the main hazards as irritating to eyes and skin and toxic to aquatic organisms, with repeated exposure possibly causing skin dryness or cracking. It names cyclohexane as a hazardous ingredient. These hazards come from the solvents in the adhesive, not from the rubber.",
        "ghs": [],
        "source": "sds-2990-2008",
        "where": "Section 2 (Hazards identification) and Section 3 (Composition)"
      },
      {
        "text": "No GHS hazard classification for the bare chlorosulfonated polyethylene polymer was found in the sources read. GreenSpec states that burning chlorosulfonated polyethylene releases hydrogen chloride and other emissions, including carbon monoxide and sulfur dioxide.",
        "ghs": [],
        "source": "greenspec-cspe",
        "where": "Environment and health section"
      }
    ],
    "failure_risks": [
      {
        "mode": "Excess outgassing in vacuum",
        "trigger": "Vacuum test of a Hypalon cable insulation in NASA's GSFC outgassing compilation",
        "consequence": "The Okonite cable insulation row shows 9.13 % total mass loss and 4.52 % collected volatile condensable material. Both are far above the low-outgassing screen that the report describes, so the cable would not meet the report's selection criteria.",
        "severity": "high",
        "source": "nasa-rp1124",
        "where": "Materials table, row GSFC3604; Introduction (selection criteria)"
      },
      {
        "mode": "Swelling or breakdown in incompatible fluids",
        "trigger": "Contact with the fluids Polymax lists as not compatible with CSM75, such as aromatic hydrocarbons and chlorinated hydrocarbons",
        "consequence": "The sources give no swelling, volume or strength-loss figures for these fluids, so the risk is described qualitatively only.",
        "severity": "moderate",
        "source": "polymax-csm75",
        "where": "Opening description paragraph (incompatibility list)"
      },
      {
        "mode": "Use below the stated low-temperature limit",
        "trigger": "Operation colder than the low end of the stated range (-35 °C for CSM75, -30 °C for compound 70.98-01)",
        "consequence": "The datasheets give no performance data below these limits, so the material cannot be assumed to flex or seal there.",
        "severity": "moderate",
        "source": "angst-csm70",
        "where": "Thermal properties block (operating temperature min.)"
      }
    ],
    "side_effects": [
      {
        "text": "When burned, the polymer releases hydrogen chloride, which GreenSpec lists among its combustion products.",
        "affects": "People near a fire and any metal or electronics it reaches",
        "source": "greenspec-cspe",
        "where": "Environment and health section"
      }
    ],
    "handling": [
      {
        "text": "Keep the rubber away from the fluids Polymax lists as not compatible, especially aromatic and chlorinated hydrocarbons.",
        "source": "polymax-csm75",
        "where": "Opening description paragraph"
      },
      {
        "text": "Specify the compound, because hardness, tensile strength and cure chemistry differ between the compounds in these sources.",
        "source": "angst-csm70",
        "where": "Header block and disclaimer"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Cable insulation and jacketing",
      "example": "NASA's outgassing compilation records a Hypalon cable insulation from Okonite (DuPont Hypalon) and marks its row as failing the report's low-outgassing criteria, so it is a test record rather than a space-cable recommendation.",
      "source": "nasa-rp1124",
      "where": "Materials table, CABLE I/C 6-61 row (GSFC3604)"
    },
    {
      "application": "structures",
      "device": "Single-ply roofing membranes for flat roofs (terrestrial building use)",
      "example": "Wikipedia says CSM is used as single-ply roofing membranes for flat roofs, and the GreenSpec page credits its weatherability and UV stability for commercial roofing.",
      "source": "wiki-hypalon",
      "where": "Applications section, Construction and automotive subsection; GreenSpec 'What is it used for?' section"
    }
  ],
  "supply": [
    {
      "subject": "Chlorosulfonated polyethylene (no USGS commodity entry)",
      "producers": [],
      "critical_lists": [],
      "recycling": "Not found in the sources read.",
      "substitutes": [],
      "source": "wiki-hypalon",
      "where": "Synthesis, Discontinuance and Current production sections"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Hypalon (CSM) encyclopedia entry (redirect from Chlorosulfonated polyethylene)",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Chlorosulfonated_polyethylene"
    },
    {
      "title": "GreenSpec: Chlorosulfonated polyethylene (CSPE), environment and health",
      "type": "database",
      "url": "https://greenspec.co.uk/building-design/chlorosulfonated-polyethylene-cspe-environment-and-health/"
    },
    {
      "title": "NASA Reference Publication 1124 Rev. 3: Outgassing Data for Selecting Spacecraft Materials",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
      "year": 1993
    },
    {
      "title": "CSM (Hypalon) Black 75 ShA datasheet (Polymax)",
      "type": "datasheet",
      "url": "https://m2dev.polymax.co.uk/media/documents/Datasheet/oring/CSM75-CSM_Hypalon_Black_75_ShA.pdf"
    },
    {
      "title": "CSM 70.98-01 technical data sheet (Angst+Pfister)",
      "type": "datasheet",
      "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
      "year": 2025
    },
    {
      "title": "Rubber Material Selection Guide: CSM or Hypalon (Robinson Rubber Products)",
      "type": "datasheet",
      "url": "https://robinsonrubber.com/wp-content/uploads/2024/02/RRPC-Rubber-Selection-Guide-Hypalon-Rubber.pdf",
      "year": 2024
    },
    {
      "title": "Safety data sheet: 2990 HYPALON Adhesive, version 1.1",
      "type": "sds",
      "url": "https://defender.ca/assets/pdf/weaver/2990-hypalon-adhesive-en-v1.1.pdf",
      "year": 2021
    },
    {
      "title": "Safety data sheet: Polymarine 2990 Hypalon Adhesive (older sheet)",
      "type": "sds",
      "url": "https://defender.ca/assets/pdf/polymarine/polymarine-2990-hypalon-adhesive.pdf",
      "year": 2008
    }
  ],
  "gaps": [
    "No flight result, space radiation test or atomic-oxygen result for any chlorosulfonated polyethylene compound was found; the NASA outgassing compilation is a ground test.",
    "The CAS number 68037-39-8 is not confirmed in an opened source. The PubChem record was behind an automated-access check and was not read.",
    "No GHS classification for the bare polymer was found in an opened source; the hazard entries come from two adhesive safety data sheets and from GreenSpec's combustion statement.",
    "Production shares by country were not found. The USGS Mineral Commodity Summaries do not cover this material, so the supply section has no share data.",
    "Heat-ageing, UV-ageing and humidity test results were not found, so the corrosion section relies on qualitative ratings.",
    "The Robinson Rubber family guide gives temperature limits in degrees Fahrenheit and a brittle point. These are family-level ranges, not one grade's value, so they are not recorded as properties.",
    "The Minnesota Rubber compounds 399ES and 399BL (hardness, tensile strength and elongation) were read on a page whose numbers could not be matched in the raw HTML, so they are not recorded.",
    "The cure chemistry conflicts: Wikipedia says CSM is cured with metal oxides, while the Angst+Pfister datasheet for compound 70.98-01 names sulfur as its curing agent.",
    "Chlorine content is given as 20 to 40 %, 20 to 45 % and 27 to 45 % in three sources; all three are recorded and none is chosen.",
    "NASA row GSFC8372 (Hypalon-coated nylon) has a total mass loss that the PDF text layer prints as garbled characters, so that row is not recorded.",
    "The NASA legend does not give a unit for cure temperature in the rows read, and the atmosphere code E-2 is not expanded in the sections read.",
    "Property names not on the canonical list are used: hardness_shore_a, total_mass_loss, collected_volatile_condensable_material, water_vapor_regained, chlorine_content and sulfur_content.",
    "Electrical properties (dielectric strength, resistivity), density of other compounds, and radiation effects were not found or not looked up."
  ],
  "story": {
    "why": "Chlorosulfonated polyethylene, sold as Hypalon, is a synthetic rubber (CSM) made from polyethylene. Chlorine and chlorosulfonyl groups give it resistance to ozone, sunlight and many chemicals, according to the datasheets and the family guide. It is a rubber for weathering and chemical service, not a structural or space-qualified material, and the sources contain no flight data for it.",
    "uses": [
      {
        "where": "Roofing and cable jacketing",
        "line": "Wikipedia lists single-ply roofing membranes for flat roofs and jacketing for electrical cables in harsh industrial environments. GreenSpec credits CSPE's weatherability and UV stability for commercial roofing."
      },
      {
        "where": "Spacecraft materials screening",
        "line": "NASA's outgassing compilation includes Hypalon cable insulation and Hypalon-coated nylon fabric. The cable row (9.13 % total mass loss) fails the report's screening criteria. The Coverlite H fabric row (0.98 % total mass loss, 0.02 % collected volatile condensable material) passes both criteria the report describes."
      }
    ],
    "can_do": [
      {
        "label": "Resists ozone, sunlight and weather",
        "line": "the family guide rates each as Excellent.",
        "scope": "material"
      },
      {
        "label": "Strength",
        "line": "Operates from -35 °C to 125 °C for CSM75 and from -30 °C to 120 °C for compound 70.98-01, per the two datasheets.",
        "scope": "material"
      },
      {
        "label": "Strength",
        "line": "Stretches to 300 % at break for compound 70.98-01, per its datasheet.",
        "scope": "material"
      },
      {
        "label": "Strength",
        "line": "Carries a hardness of 70 Shore A (compound 70.98-01) to 75 ShA (CSM75), so it is a firm elastomer rather than a soft one.",
        "scope": "material"
      }
    ],
    "compare": "The compounds in these sources differ widely. Compound 70.98-01 is 70 Shore A with 300 % elongation at break and 8.00 N/mm² tensile strength. CSM75 is 75 ShA and is rated from -35 °C to 125 °C. Among NASA's rows, the same material family spans total mass loss from 0.98 % to 9.13 %, so the cure and the product matter more than the family name. The coated fabric row passes the screening criteria and the cable row fails them.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Maximum operating temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      },
      {
        "label": "Elongation at break",
        "benchmark": "elongation",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep it away from the fluids Polymax lists as not compatible, especially aromatic and chlorinated hydrocarbons.",
      "Treat smoke from a fire as hazardous: the polymer releases hydrogen chloride when burned.",
      "Specify the compound, because hardness, strength and cure differ between the compounds in these sources."
    ],
    "good_for": [
      "Ozone, sunlight and weather exposure, where the family guide rates resistance as Excellent.",
      "Flexible jackets and roofing membranes on the ground, per Wikipedia."
    ],
    "watch_out": [
      "Vacuum outgassing: the Okonite cable row shows 9.13 % total mass loss, far above the report's screening criteria.",
      "Sources disagree on chlorine content: 20 to 40 %, 20 to 45 % and 27 to 45 %.",
      "Cure chemistry is disputed: Wikipedia says metal oxides, and the Angst+Pfister datasheet names sulfur.",
      "The hazard data come from a solvent adhesive, not from the bare polymer."
    ],
    "verdict": "Chlorosulfonated polyethylene (Hypalon) is a weather- and ozone-resistant rubber, with datasheet operating ranges of -35 °C to 125 °C for CSM75. Its weak point is vacuum outgassing: the one cable row in NASA's table fails the screen. No hazard classification for the bare polymer was found.",
    "recipe": {
      "line": "Chlorosulfonated polyethylene is made by treating polyethylene with chlorine and sulfur dioxide under UV light, which replaces hydrogen atoms along the chain with chlorine and adds chlorosulfonyl (ClSO2) groups (Wikipedia). The chlorosulfonyl groups are the cure sites. Wikipedia says CSM is cured with metal oxides, while the Angst+Pfister datasheet for compound 70.98-01 names sulfur as its curing agent.",
      "parts": [
        {
          "name": "Polyethylene backbone",
          "role": "Low-density or high-density polyethylene is the starting polymer; chlorine and chlorosulfonyl groups are added along its chain (Wikipedia)."
        },
        {
          "name": "Chlorine",
          "symbol": "Cl",
          "role": "Disrupts the crystallinity of the polyethylene so the polymer becomes an elastomer, and gives flame resistance and cold flexibility (Wikipedia; Polymax)."
        },
        {
          "name": "Sulfur",
          "symbol": "S",
          "role": "Present in the chlorosulfonyl (ClSO2) groups, which react with the cure agent to form cross-links (Wikipedia)."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "No hazard classification for the bare CSM polymer was found. The hazard data come from a solvent adhesive that carries the Hypalon name.",
        "points": [
          {
            "label": "Adhesive",
            "line": "The 2021 safety data sheet for 2990 HYPALON Adhesive gives the signal word Danger, with flammable-liquid, eye-irritant, skin-sensitiser and drowsiness hazards. The older 2008 sheet names cyclohexane as a hazardous ingredient."
          },
          {
            "label": "In a fire",
            "line": "GreenSpec says burning the polymer releases hydrogen chloride and other emissions, including carbon monoxide and sulfur dioxide."
          }
        ],
        "level": 1,
        "verdict": "Hazards from an adhesive, not the polymer"
      },
      {
        "title": "If it fails in vacuum",
        "lead": "The only space-related result is a ground outgassing test, and the cable row fails the report's criteria.",
        "points": [
          {
            "label": "Cable insulation",
            "line": "The Okonite cable insulation (DuPont Hypalon) in NASA's table shows 9.13 % total mass loss and 4.52 % collected volatile condensable material."
          }
        ],
        "level": 2,
        "verdict": "The one vacuum test here fails"
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Fluids",
            "line": "Polymax lists propane, butane, aliphatic oils, polar solvents, phosphate-ester fluids, aromatic hydrocarbons and chlorinated hydrocarbons as not compatible with CSM75."
          },
          {
            "label": "Cold",
            "line": "The lowest stated operating temperatures are -35 °C for CSM75 and -30 °C for compound 70.98-01."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-02",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 18,
    "unreachable": 1,
    "caveats": 4,
    "note": "Values read by an AI assistant on 2026-11-02 from the pages and PDFs named in each entry. Unreachable: the PubChem record (automated-access check). Caveats: datasheet values are for specific compounds and are not guaranteed; chlorine ranges disagree across sources; the NASA rows are ground outgassing tests; the hazard data come from adhesive safety data sheets, not the polymer."
  },
  "sources": {
    "wiki-hypalon": {
      "title": "Hypalon (encyclopedia entry; the URL given is a redirect from Chlorosulfonated polyethylene)",
      "url": "https://en.wikipedia.org/wiki/Chlorosulfonated_polyethylene",
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "greenspec-cspe": {
      "title": "Chlorosulfonated polyethylene (CSPE): environment and health (GreenSpec)",
      "url": "https://greenspec.co.uk/building-design/chlorosulfonated-polyethylene-cspe-environment-and-health/",
      "kind": "web",
      "license": "Web page (cited, not reproduced)"
    },
    "nasa-rp1124": {
      "title": "Outgassing Data for Selecting Spacecraft Materials, NASA Reference Publication 1124, Revision 3 (Campbell and Scialdone, GSFC)",
      "id": "NTRS 19940017416",
      "url": "https://ntrs.nasa.gov/api/citations/19940017416/downloads/19940017416.pdf",
      "year": 1993,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "polymax-csm75": {
      "title": "CSM (Hypalon) Black 75 ShA, product CSM75 (Polymax)",
      "url": "https://m2dev.polymax.co.uk/media/documents/Datasheet/oring/CSM75-CSM_Hypalon_Black_75_ShA.pdf",
      "kind": "datasheet",
      "license": "Supplier datasheet (cited, not reproduced)"
    },
    "angst-csm70": {
      "title": "Technical Data Sheet CSM 70.98-01 (Angst+Pfister), status released",
      "id": "compound code CSM 70.98-01",
      "url": "https://www.apsoparts.com/media/downloads/asset//std.lang.all/8-/01/CSM_70_98-01.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "rrpc-csm": {
      "title": "Rubber Material Selection Guide: CSM or Hypalon, chlorosulphonated polyethylene (Robinson Rubber Products)",
      "url": "https://robinsonrubber.com/wp-content/uploads/2024/02/RRPC-Rubber-Selection-Guide-Hypalon-Rubber.pdf",
      "year": 2024,
      "kind": "datasheet",
      "license": "Supplier guide (cited, not reproduced)"
    },
    "sds-2990-rev": {
      "title": "Safety data sheet, 2990 HYPALON Adhesive, version 1.1 (revision date 15/12/2021)",
      "url": "https://defender.ca/assets/pdf/weaver/2990-hypalon-adhesive-en-v1.1.pdf",
      "year": 2021,
      "kind": "datasheet",
      "license": "Manufacturer safety data sheet (cited, not reproduced)"
    },
    "sds-2990-2008": {
      "title": "Safety data sheet, Polymarine 2990 Hypalon Adhesive (issued 24/04/2008)",
      "url": "https://defender.ca/assets/pdf/polymarine/polymarine-2990-hypalon-adhesive.pdf",
      "year": 2008,
      "kind": "datasheet",
      "license": "Manufacturer safety data sheet (cited, not reproduced)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/csm-hypalon/"
}