spore: profile
id: epdm
spore_version: 0.2
family: polyolefins
name: Ethylene propylene diene monomer rubber (EPDM)
abbreviation: EPDM
role: Seal, O-ring and hose elastomer for hot water, steam and weathering service
category: polymers
type: polyolefins
summary: |
  EPDM (ethylene propylene diene monomer) is a synthetic terpolymer rubber made from ethylene, propylene and a small amount of a diene that carries the cure sites. Polymax's sulphur-cured 70 Shore A O-ring compound is rated -30 to 125 °C, and its peroxide-cured 70 Shore A compound -30 to 150 °C. Parker's O-Ring Handbook gives up to 150 °C in water and steam (204 °C maximum), cold flexibility to about -57 °C, and says EPDM deteriorates in petroleum lubricants.
best_for: Seals for hot water, steam, ozone and weathering, and for glycol or silicone brake fluids (Polymax, Parker)
weakest_at: Petroleum lubricants (Parker says it deteriorates in them), and UV exposure, which crosslinks and oxidises the rubber in the one UV-aged study read here
identity:
  formula: Terpolymer of ethylene, propylene and a diene (ethylidene norbornene, dicyclopentadiene or vinyl norbornene). Saturated polyethylene-type backbone with a small diene comonomer that provides the cure sites.
  source: wikipedia-epdm
  where: Composition section (monomers, diene types, diene content); the Polymax sulphur-cured datasheet describes EPDM as a terpolymer of ethylene, propylene and diene monomers
  designations:
    - system: ASTM
      code: D1418
      note: M-class elastomer with a saturated polyethylene-type chain (EPDM)
      source: wikipedia-epdm
      where: Classification section, M-Class rubber under ASTM D-1418
tags:
  environments: []
  stresses:
    - uv
    - extreme-heat
    - extreme-cold
    - vacuum-and-outgassing
    - total-radiation-dose
  applications:
    - mechanisms
properties:
  - benchmark: max_service_temp
    label: Heat resistance in water and steam (general EPDM)
    value: 150
    unit: °C
    scope: material
    conditions:
      medium: water and/or steam
      note: Parker gives 204 °C (400 °F) as the maximum, with shorter life at that level
    method: Statement in the Parker O-Ring Handbook, EPDM section
    status: ground
    source: parker-handbook
    where: Section 2.2.4 Ethylene Propylene Rubber (EPR, EPDM), heat resistance
  - benchmark: max_service_temp
    label: Hot water and steam with special compounds
    value: 260
    unit: °C
    scope: material
    conditions:
      medium: hot water and steam
      compound: special compounds (Parker does not name them in this statement)
    method: Statement in the Parker O-Ring Handbook, EPDM section
    status: ground
    source: parker-handbook
    where: Section 2.2.4, chemical resistance (paragraph beginning Hot water and steam up to 149 °C)
  - benchmark: min_service_temp
    label: Cold flexibility (general EPDM)
    value: -57
    unit: °C
    scope: material
    conditions:
      basis: Parker wording is approximately -57 °C (-70 °F)
    method: Statement in the Parker O-Ring Handbook, EPDM section
    status: ground
    source: parker-handbook
    where: Section 2.2.4, cold flexibility
  - benchmark: cte
    label: Linear thermal expansion coefficient, 24 to 191 °C
    value: 0.000089
    unit: in/in/°F
    scope: material
    conditions:
      range: 24 to 191 °C (75 to 375 °F)
      basis: Ethylene Propylene row; printed as 8.9 x 10-5
    method: Parker table of linear thermal expansion, printed in US units
    status: ground
    source: parker-handbook
    where: Table Linear Thermal Expansion of Typical Elastomers, Ethylene Propylene row (beside section 2.4.19)
  - benchmark: vacuum_weight_loss
    label: Weight loss in vacuum, E0515-80 ethylene propylene compound
    value: 0.39
    unit: '%'
    scope: material
    conditions:
      vacuum: about 1 x 10-6 torr
      time: 336 h
      temperature: 25 °C
    method: Parker weight loss of compounds in vacuum test, which is not the ASTM E595 TML method
    status: ground
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19 (row E0515-80)
  - benchmark: vacuum_weight_loss
    label: Weight loss in vacuum, E0692-75 ethylene propylene compound
    value: 0.76
    unit: '%'
    scope: material
    conditions:
      vacuum: about 1 x 10-6 torr
      time: 336 h
      temperature: 25 °C
    method: Parker weight loss of compounds in vacuum test, which is not the ASTM E595 TML method
    status: ground
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19 (row E0692-75)
  - benchmark: vacuum_weight_loss
    label: Weight loss in vacuum, E0529-60 ethylene propylene compound
    value: 0.92
    unit: '%'
    scope: material
    conditions:
      vacuum: about 1 x 10-6 torr
      time: 336 h
      temperature: 25 °C
    method: Parker weight loss of compounds in vacuum test, which is not the ASTM E595 TML method
    status: ground
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19 (row E0529-60)
  - benchmark: compression_set
    label: Compression set after gamma dose, E0740-75 ethylene propylene
    value: 28.6
    unit: '%'
    scope: material
    conditions:
      dose: 10^7 rad gamma (the PDF prints the exponent as a superscript; read as 10^7 from the table header and footnote 1)
      temperature: room temperature
      compound: E0740-75, polymer ethylene propylene
    method: Parker radiation table, compression set after exposure to gamma radiation
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table
  - benchmark: compression_set
    label: Compression set after gamma dose, E0515-80 ethylene propylene
    value: 46.6
    unit: '%'
    scope: material
    conditions:
      dose: 10^7 rad gamma (superscript in PDF; read as 10^7 as for E0740-75)
      temperature: room temperature
      compound: E0515-80, polymer ethylene propylene
    method: Parker radiation table, compression set after exposure to gamma radiation
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table
  - benchmark: max_service_temp
    label: Temperature for 90% set after 1000 h, E0740-75 ethylene propylene
    value: 177
    unit: °C
    scope: material
    conditions:
      compound: E0740-75
      basis: temperature at which a 0.139 in cross-section ring takes 90% compression set after 1000 h, not exposed to radiation or fluids
    method: Parker radiation table, footnote 2
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table, footnote 2
  - benchmark: max_service_temp
    label: Temperature for 90% set after 1000 h, E0515-80 ethylene propylene
    value: 149
    unit: °C
    scope: material
    conditions:
      compound: E0515-80
      basis: 'as for E0740-75: 90% compression set after 1000 h, not exposed to radiation or fluids'
    method: Parker radiation table, footnote 2
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table, footnote 2
  - benchmark: max_service_temp
    label: Operating temperature range, sulphur-cured 70 ShA O-ring
    value: 125
    unit: °C
    scope: material
    conditions:
      cure: sulphur-based
      grade: EPDM 70 ShA, black
    method: Operating temperature range printed on the datasheet
    status: ground
    source: polymax-sulphur
    where: Operating temperature range line
  - benchmark: min_service_temp
    label: Operating temperature range, lower limit, sulphur-cured 70 ShA O-ring
    value: -30
    unit: °C
    scope: material
    conditions:
      cure: sulphur-based
      grade: EPDM 70 ShA, black
    method: Operating temperature range printed on the datasheet
    status: ground
    source: polymax-sulphur
    where: Operating temperature range line
  - benchmark: min_service_temp
    label: Low temperature resistance, sulphur-cured 70 ShA
    value: -40
    unit: °C
    scope: material
    conditions:
      test: ASTM D 1329 TR10
      cure: sulphur-based
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Low Temperature Resistance row
  - benchmark: hardness
    label: Hardness, sulphur-cured 70 ShA
    value: 71
    unit: Shore A
    scope: material
    conditions:
      test: ASTM D 2240
      grade: EPDM 70 ShA, black
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Hardness row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, sulphur-cured 70 ShA
    value: 10.5
    unit: MPa
    scope: material
    conditions:
      test: ASTM D 412
      cure: sulphur-based
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Tensile Strength row
  - benchmark: elongation
    label: Elongation at break, sulphur-cured 70 ShA
    value: 255
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 412
      cure: sulphur-based
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Elongation row
  - benchmark: density
    label: Specific gravity, sulphur-cured 70 ShA
    value: 1.19
    unit: g/cm3
    scope: material
    conditions:
      test: ASTM D 297
      tolerance: printed as 1.19 +/- 0.03
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Specific Gravity row
  - benchmark: compression_set
    label: Compression set, sulphur-cured 70 ShA
    value: 38
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 395 B
      time: 22 h
      temperature: 125 °C
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Compression Set row
  - benchmark: tear_strength
    label: Tear resistance, sulphur-cured 70 ShA
    value: 49
    unit: N/mm
    scope: material
    conditions:
      test: ASTM D 624 C
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-sulphur
    where: Physical property table, Tear Resistance row
  - benchmark: max_service_temp
    label: Operating temperature range, peroxide-cured 70 ShA O-ring
    value: 150
    unit: °C
    scope: material
    conditions:
      cure: peroxide
      grade: EPDM 70 ShA peroxide cured, black
    method: Operating temperature range printed on the datasheet
    status: ground
    source: polymax-peroxide
    where: Operating temperature range line
  - benchmark: min_service_temp
    label: Operating temperature range, lower limit, peroxide-cured 70 ShA O-ring
    value: -30
    unit: °C
    scope: material
    conditions:
      cure: peroxide
      grade: EPDM 70 ShA peroxide cured, black
    method: Operating temperature range printed on the datasheet
    status: ground
    source: polymax-peroxide
    where: Operating temperature range line
  - benchmark: min_service_temp
    label: Low temperature resistance, peroxide-cured 70 ShA
    value: -42
    unit: °C
    scope: material
    conditions:
      test: ISO 2921
      criterion: printed as < -37 °C in the test column
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Low Temperature Resistance row
  - benchmark: hardness
    label: Hardness, peroxide-cured 70 ShA
    value: 70
    unit: Shore A
    scope: material
    conditions:
      test: ASTM D 2240
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Hardness row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, peroxide-cured 70 ShA
    value: 17
    unit: MPa
    scope: material
    conditions:
      test: ISO 37 type 2
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Tensile Strength row
  - benchmark: elongation
    label: Elongation at break, peroxide-cured 70 ShA
    value: 220
    unit: '%'
    scope: material
    conditions:
      test: ISO 37 type 2
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Elongation row
  - benchmark: density
    label: Specific gravity, peroxide-cured 70 ShA
    value: 1.14
    unit: g/cm3
    scope: material
    conditions:
      test: ISO 2781 A
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Specific Gravity row
  - benchmark: compression_set
    label: Compression set, peroxide-cured 70 ShA
    value: 13
    unit: '%'
    scope: material
    conditions:
      test: ISO 815 B
      cure: peroxide
      note: time and temperature not printed in the table row
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Compression Set row
  - benchmark: tear_strength
    label: Tear resistance, peroxide-cured 70 ShA
    value: 32
    unit: N/mm
    scope: material
    conditions:
      test: ISO 34-1 C
      cure: peroxide
    method: Typical value from the supplier datasheet
    status: ground
    source: polymax-peroxide
    where: Physical property table, Tear Resistance row
  - benchmark: max_service_temp
    label: Tested operating range, EP70 EPDM compound
    value: 145
    unit: °C
    scope: material
    conditions:
      compound: EP70 (EPDM), black
      column: tested value; the required column is n/a
    method: Technical data sheet, operating temperature range, tested column
    status: ground
    source: polymax-ep70
    where: Thermal Properties, Operating Temperature Range row
  - benchmark: min_service_temp
    label: Tested operating range lower limit, EP70 EPDM compound
    value: -45
    unit: °C
    scope: material
    conditions:
      compound: EP70 (EPDM), black
      column: tested value
    method: Technical data sheet, operating temperature range, tested column
    status: ground
    source: polymax-ep70
    where: Thermal Properties, Operating Temperature Range row
  - benchmark: compression_set
    label: Compression set, EP70 EPDM compound
    value: 13
    unit: '%'
    scope: material
    conditions:
      test: 70 °C for 22 hours
      compound: EP70 (EPDM), black
    method: Tested value on the technical data sheet
    status: ground
    source: polymax-ep70
    where: Thermal Properties, Compression Set Test row, tested column
  - benchmark: glass_transition_temperature
    label: DMA transition temperature, new UV-weathering EPDM housing
    value: -42
    unit: °C
    scope: material
    conditions:
      material: industrial EPDM housing with aluminium trihydrate filler (Table 1 of the paper), peroxide cured
      test: DMA, dual cantilever, 1 Hz, 3 °C/min
    method: Temperature label on the tan delta plot in Fig. 3 legend, read as the DMA transition
    status: ground
    source: bencherif-2019
    where: Figure 3 legend (tan delta vs temperature), New sample
  - benchmark: glass_transition_temperature
    label: DMA transition temperature, after 2160 h UV ageing
    value: -37
    unit: °C
    scope: material
    conditions:
      material: industrial EPDM housing with aluminium trihydrate filler, peroxide cured
      exposure: UVA 340 nm, 45 °C, dry, 2160 h
    method: Temperature label on the tan delta plot in Fig. 3 legend
    status: ground
    source: bencherif-2019
    where: Figure 3 legend (tan delta vs temperature), 2160 h (UV Aging)
  - benchmark: dtg_peak_temperature
    label: TGA DTG peak temperature, new filled EPDM
    value: 365
    unit: °C
    scope: material
    conditions:
      atmosphere: nitrogen
      heating_rate: 10 °C/min, 25 to 800 °C
      material: industrial EPDM housing with aluminium trihydrate filler
    method: Thermogravimetric analysis, DTG peak temperature
    status: ground
    source: bencherif-2019
    where: Table 3 TGA and DTG results summary, New row
  - benchmark: dtg_peak_temperature
    label: TGA DTG peak temperature, after 2160 h UV ageing
    value: 354
    unit: °C
    scope: material
    conditions:
      atmosphere: nitrogen
      heating_rate: 10 °C/min, 25 to 800 °C
      exposure: UVA 340 nm, 45 °C, 2160 h
    method: Thermogravimetric analysis, DTG peak temperature
    status: ground
    source: bencherif-2019
    where: Table 3 TGA and DTG results summary, 2160 h aged row
corrosion:
  - environment: Hot air, 125 °C, 70 h (sulphur-cured 70 ShA)
    headline: Hot air ageing hardens the sulphur-cured grade and removes some strength and elongation.
    effect: After 70 h at 125 °C in air (ASTM D 573), hardness rose by 4 points, tensile strength fell 14% and ultimate elongation fell 24%.
    rating: moderate
    conditions:
      time: 70 h
      temperature: 125 °C
      standard: ASTM D 573
    source: polymax-sulphur
    where: Aging property table, Air row
  - environment: Water, 100 °C, 70 h (sulphur-cured 70 ShA)
    headline: Hot water swells the sulphur-cured grade slightly.
    effect: After 70 h at 100 °C in water (ASTM D 471), volume rose by 2%.
    rating: low
    conditions:
      time: 70 h
      temperature: 100 °C
      standard: ASTM D 471
    source: polymax-sulphur
    where: Aging property table, Water row
  - environment: Hot air, 150 °C, 70 h (peroxide-cured 70 ShA)
    headline: The peroxide-cured grade holds up better in hot air, losing about a quarter of its strength and elongation.
    effect: After 70 h at 150 °C in air (ISO 188 B), hardness rose by 4 points, tensile strength fell 25% and ultimate elongation fell 25%. Volume fell 0.4%.
    rating: moderate
    conditions:
      time: 70 h
      temperature: 150 °C
      standard: ISO 188 B
    source: polymax-peroxide
    where: Aging property table, Air row
  - environment: Water, 100 °C, 70 h (peroxide-cured 70 ShA)
    headline: Hot water barely changes the peroxide-cured grade.
    effect: After 70 h at 100 °C in water (ISO 1817), hardness changed by -1 point, tensile strength by -4%, ultimate elongation by -7%, and volume rose by 1.3%.
    rating: low
    conditions:
      time: 70 h
      temperature: 100 °C
      standard: ISO 1817
    source: polymax-peroxide
    where: Aging property table, Water row
  - environment: Heat, 100 °C, 70 h (EP70 compound, tested)
    headline: The EP70 compound changes little after 70 h at 100 °C.
    effect: After 70 h at 100 °C, hardness changed by +3 points, tensile strength by +1% and elongation by -9%.
    rating: low
    conditions:
      time: 70 h
      temperature: 100 °C
    source: polymax-ep70
    where: Heat Resistance Test row, tested column
  - environment: Steam at 288 °C (550 °F), 70 h, special ethylene propylene compound E0962-90
    headline: A special EPDM compound shows little change after long steam exposure at 288 °C.
    effect: Parker says compound E0962-90 showed very little change in physical properties after 70 hours exposure to steam at 288 °C (550 °F). Parker gives no number for ordinary compounds.
    rating: low
    conditions:
      time: 70 h
      temperature: 288 °C
      compound: E0962-90
    source: parker-handbook
    where: Steam and water sealing text beside the Hot water and steam discussion (section number not read in this run)
  - environment: Petroleum lubricants in contact with the seal
    headline: EPDM deteriorates in petroleum lubricants, a key limit for this rubber.
    effect: Parker says that when sealing steam or water with ethylene propylene rubber, the seal will deteriorate when exposed to petroleum lubricants. Parker suggests silicone oil, glycerin or ethylene glycol when lubrication is required.
    rating: severe
    conditions:
      basis: qualitative statement, no test conditions given
    source: parker-handbook
    where: Steam and water sealing text beside compound E0962-90 (section number not read in this run)
  - environment: UV weathering, UVA 340 nm at 45 °C, dry, up to 2160 h (filled EPDM housing)
    headline: UV crosslinks and oxidises the filled EPDM, and its surface becomes less water-repellent.
    effect: The paper reports a crosslinking process along weathering, oxygenated species that rise with time, and a surface contact angle that falls linearly with ageing time. The paper prints no contact-angle value. Its TGA showed no loss of thermal stability in the components. The lamps gave 0.89 W/m2/nm with no condensation, following the ASTM G154 approach the paper cites.
    rating: moderate
    conditions:
      exposure: UVA 340 nm, 45 °C, dry, up to 2160 h
      irradiance: 0.89 W/m2/nm
      material: EPDM with aluminium trihydrate filler, peroxide cured
    source: bencherif-2019
    where: Sections 2.2 and 4 (Conclusions)
risks:
  hazards:
    - text: No classification was found for the EPDM compound in this run. No EPDM safety data sheet was retrieved.
      ghs: []
      source: polymax-sulphur
      where: not found
    - text: Ethylene is an extremely flammable gas that may explode if heated, and may cause drowsiness or dizziness. This is for the monomer, not the EPDM compound.
      ghs:
        - H220
        - H280
        - H336
      source: pubchem-ethylene
      where: GHS Classification (CID 6325), aggregated
    - text: Propylene is an extremely flammable gas and a gas under pressure that may explode if heated. This is for the monomer, not the EPDM compound.
      ghs:
        - H220
        - H280
      source: pubchem-propylene
      where: GHS Classification (CID 8252), aggregated
    - text: Ethylidene norbornene (the usual diene) is a flammable liquid that may be fatal if swallowed and enters airways. PubChem also lists skin and eye irritation, harm if inhaled, and an aquatic hazard. Percentages are PubChem's notification shares.
      ghs:
        - H226
        - H304
        - H315
        - H319
        - H332
        - H335
        - H411
      source: pubchem-enb
      where: GHS Classification (CID 27756), aggregated
  failure_risks:
    - mode: Hardening and loss of elasticity after heat ageing
      trigger: Service at 125 °C in air for 70 h (sulphur-cured grade)
      consequence: Tensile strength falls 14% and elongation falls 24%, with a 4-point rise in hardness
      severity: moderate
      source: polymax-sulphur
      where: Aging property table, Air row
    - mode: Permanent set after long compression at heat
      trigger: Compressed for 22 h at 125 °C (sulphur-cured) or the same test on the EP70 compound
      consequence: Set of 38% for the sulphur-cured grade, against 13% for the peroxide-cured and EP70 grades. The seal recovers less of its shape and may leak.
      severity: moderate
      source: polymax-sulphur
      where: Physical property table, Compression Set row
    - mode: Deterioration in petroleum lubricants
      trigger: Seal in contact with petroleum lubricants, or lubricated with them
      consequence: Parker says EPDM deteriorates when exposed to petroleum lubricants; use silicone oil, glycerin or ethylene glycol instead
      severity: critical
      source: parker-handbook
      where: Steam and water sealing text beside compound E0962-90 (section number not read in this run)
    - mode: Stiffening below the low-temperature limit
      trigger: Operation below -30 °C (sulphur-cured) or -42 °C (peroxide-cured, ISO 2921)
      consequence: The seal loses flexibility and may leak
      severity: moderate
      source: polymax-peroxide
      where: Operating temperature range line and Low Temperature Resistance row
    - mode: Compression set after gamma dose
      trigger: 10^7 rad gamma at room temperature
      consequence: E0740-75 takes a 28.6% set and E0515-80 a 46.6% set, which lowers the seal's recovery
      severity: moderate
      source: parker-handbook
      where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table
    - mode: UV photo-oxidation
      trigger: UVA 340 nm at 45 °C, dry, for up to 2160 h
      consequence: Crosslinking and oxygenated species form, and the surface becomes less water-repellent. The transition temperature moves from -42 °C to -37 °C.
      severity: moderate
      source: bencherif-2019
      where: Sections 2.2 and 4 (Conclusions); Figure 3 legend
  side_effects:
    - text: No side effects found in this run.
      affects: Not sourced
      source: parker-handbook
      where: not found
  handling:
    - text: Read the safety data sheet for the specific EPDM compound before use. None was retrieved in this run.
      source: polymax-sulphur
      where: not found
    - text: Keep ethylene and propylene gases away from heat. PubChem's H280 says they may explode if heated.
      source: pubchem-ethylene
      where: GHS H280 statement (CID 6325)
    - text: Do not lubricate EPDM seals with petroleum lubricants. Parker suggests silicone oil, glycerin or ethylene glycol.
      source: parker-handbook
      where: Steam and water sealing text beside compound E0962-90
  mitigations:
    - text: Choose a peroxide-cured compound for service up to 150 °C. Polymax rates the sulphur-cured grade to 120 °C in its text, and its operating range line says 125 °C.
      source: polymax-peroxide
      where: Description paragraph and operating temperature range line
    - text: Lubricate with silicone oil, glycerin or ethylene glycol rather than petroleum lubricants.
      source: parker-handbook
      where: Steam and water sealing text beside compound E0962-90
uses:
  - application: mechanisms
    device: O-ring seals in brake systems that use glycol (DOT 3 and 4) or silicone (DOT 5) fluids
    example: Polymax says EPDM is particularly useful when sealing in brake systems that use glycol or silicone based fluids. Parker says EPDM is particularly useful in phosphate-ester hydraulic fluids and in brake systems that use glycol bases. No space mission was named.
    source: polymax-sulphur
    where: Description paragraph
  - application: mechanisms
    device: O-rings and gaskets in vacuum equipment, tested to the ASTM E 595 outgassing method
    example: NASA's outgassing database lists EPDM O-rings and gaskets tested to ASTM E 595, with total mass loss and volatile condensable results per part. The values are not recorded in this file (see gaps). No spacecraft flight use was named in the sources read.
    source: nasa-outgassing
    where: Database rows GSFC36138, GSFC34174, GFC37364, GSFC36351
supply:
  - subject: Sulphur, the curing agent for sulphur-cured EPDM
    abundance: World sulphur production was 83,900 thousand t in 2024 and 84,000 thousand t in 2025 (USGS). China produced 19,000 thousand t in both years. Most sulphur is recovered from petroleum and natural gas processing.
    producers: []
    critical_lists: []
    recycling: Not stated in the USGS summary read here.
    substitutes: []
    source: usgs-sulfur
    where: World Production and Reserves table; Domestic Production and Use
media: []
documents:
  - title: Polymax EPDM 70 ShA sulphur-cured O-ring datasheet
    type: datasheet
    url: https://www.polymax.co.uk/media/documents/Datasheet/epdm_70sha_oring_polymax.pdf
  - title: Polymax EPDM 70 ShA peroxide-cured O-ring datasheet
    type: datasheet
    url: https://www.polymax.co.uk/media/documents/Datasheet/epdm_70sha_peroxide_oring_polymax.pdf
  - title: Polymax EP70 EPDM technical data sheet
    type: datasheet
    url: https://www.polymax.co.uk//media/documents/Datasheet/ORing_EPDM-70.pdf
  - title: Parker O-Ring Handbook (copy hosted by the University of Arizona)
    type: report
    url: https://nfc.arizona.edu/sites/default/files/2022-02/parker_o-ring_handbook.pdf
    year: 2022
  - title: USGS Mineral Commodity Summaries 2026, sulfur
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-sulfur.pdf
    year: 2026
  - title: NASA Goddard outgassing database (ASTM E 595 results)
    type: database
    url: https://etd.gsfc.nasa.gov/capabilities/outgassing-database/
  - title: Multiscale analysis of polymeric insulator degradation in simulated arid conditions (EPDM UV ageing)
    type: paper
    url: https://orbi.umons.ac.be/bitstream/20.500.12907/37612/1/Bencherif_et_al-2019-Journal_of_Electrical_Engineering__Technology.pdf
    year: 2019
gaps:
  - Ethylene and propylene production shares by country, and EPDM producer shares, were not found in a source read in this run. Market-research summaries conflicted with each other and were not used.
  - Feedstock source for ethylene, propylene and the diene (natural gas or oil refining) is not stated in any source read here.
  - Monomer ratio, ethylene content and the diene used in the Polymax grades are not printed in any source read. Wikipedia gives a diene content of 2 to 12% but no ethylene figure.
  - The NASA outgassing database loads its table by script. EPDM rows (total mass loss, CVCM and WVR under ASTM E 595) were read from the rendered table in this run, but the static page the value check fetches does not print them, so no outgassing value is recorded in this file. Re-check the database directly before adding them. Rows are per part from several manufacturers, not one grade, and its shorthand test codes (for example E-2, E-4) are not decoded.
  - NASA RP-1124 Revision 4 was read in this run and contains no EPDM entry. The online database above replaces it.
  - Atomic oxygen erosion of EPDM was searched for in this run and not found. Nothing on EPDM in low Earth orbit is recorded here.
  - 'Parker vacuum weight loss is recorded under the benchmark name vacuum_weight_loss, which is not in property-canon.yaml. Other non-canonical names: compression_set, hardness, tear_strength, dtg_peak_temperature.'
  - Ultraviolet ageing data come from one paper on a filled, peroxide-cured housing. No UV data for unfilled EPDM were found, and no humidity ageing beyond the 70 h water tests on the Polymax datasheets.
  - Parker's Good ratings for steam and water in the radiation table are words, not numbers, and were not used as values.
  - 'Hazard data for the EPDM compound itself: no safety data sheet was retrieved in this run. PubChem gives the monomers only.'
  - 'Designations: the Polymax ASTM D2000 line codes (for example M5 CA710 A15 B35) belong to specific Polymax grades, not to EPDM in general, and are not listed. The only general designation read is ASTM D1418 M-class, from Wikipedia.'
  - Amine, nitrogen tetroxide and other liquid rocket propellant compatibility of EPDM were not searched in this run.
  - Producers of EPDM (Lanxess Arlanxeo, ExxonMobil, Dow, Kumho and others) are named in market-research summaries only, and no company page was read.
  - Polymax E70 datasheet is hosted on a development domain (m2dev.polymax.co.uk) and was not used.
  - Wikipedia's property table (maximum service temperature 150 °C, minimum -50 °C, glass transition -54 °C) carries a citation-needed tag and was not used as a value.
sources:
  parker-handbook:
    title: Parker O-Ring Handbook (copy hosted by the University of Arizona)
    id: Parker O-Ring Handbook, copy at the University of Arizona
    url: https://nfc.arizona.edu/sites/default/files/2022-02/parker_o-ring_handbook.pdf
    year: 2022
    kind: handbook
    license: Manufacturer handbook, cited
  polymax-sulphur:
    title: EPDM 70 ShA sulphur-cured O-ring datasheet, Polymax
    id: Polymax datasheet epdm_70sha_oring
    url: https://www.polymax.co.uk/media/documents/Datasheet/epdm_70sha_oring_polymax.pdf
    kind: datasheet
    license: Supplier datasheet, cited
  polymax-peroxide:
    title: EPDM 70 ShA peroxide-cured O-ring datasheet, Polymax
    id: Polymax datasheet epdm_70sha_peroxide_oring
    url: https://www.polymax.co.uk/media/documents/Datasheet/epdm_70sha_peroxide_oring_polymax.pdf
    kind: datasheet
    license: Supplier datasheet, cited
  polymax-ep70:
    title: EP70 EPDM technical data sheet, Polymax
    id: Polymax technical data sheet ORing_EPDM-70
    url: https://www.polymax.co.uk//media/documents/Datasheet/ORing_EPDM-70.pdf
    kind: datasheet
    license: Supplier datasheet, cited
  nasa-outgassing:
    title: NASA Goddard outgassing database, EPDM rows
    id: NASA GSFC outgassing database, Material filter EPDM
    url: https://etd.gsfc.nasa.gov/capabilities/outgassing-database/
    kind: database
    license: NASA public data
  usgs-sulfur:
    title: Mineral Commodity Summaries 2026, Sulfur, U.S. Geological Survey
    id: USGS MCS 2026, sulfur
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-sulfur.pdf
    year: 2026
    kind: report
    license: U.S. Government work, public domain
  pubchem-ethylene:
    title: PubChem, Ethylene (CID 6325)
    id: PubChem CID 6325
    url: https://pubchem.ncbi.nlm.nih.gov/compound/6325
    kind: database
    license: PubChem, public database
  pubchem-propylene:
    title: PubChem, Propylene (CID 8252)
    id: PubChem CID 8252
    url: https://pubchem.ncbi.nlm.nih.gov/compound/8252
    kind: database
    license: PubChem, public database
  pubchem-enb:
    title: PubChem, Ethylidenenorbornene (CID 27756)
    id: PubChem CID 27756
    url: https://pubchem.ncbi.nlm.nih.gov/compound/27756
    kind: database
    license: PubChem, public database
  wikipedia-epdm:
    title: Wikipedia, EPDM rubber
    id: Wikipedia EPDM rubber; composition and classification only
    url: https://en.wikipedia.org/wiki/EPDM_rubber
    kind: web
    license: CC BY-SA 4.0
  bencherif-2019:
    title: 'Multiscale Analysis of the Polymeric Insulators Degradation in Simulated Arid Environment Conditions: Cross-Correlation Assessment, Journal of Electrical Engineering and Technology'
    id: DOI 10.1007/s42835-019-00217-7
    url: https://orbi.umons.ac.be/bitstream/20.500.12907/37612/1/Bencherif_et_al-2019-Journal_of_Electrical_Engineering__Technology.pdf
    year: 2019
    kind: paper
    license: Springer, cited
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 36
  note: Written on 2026-10-26 from Parker O-Ring Handbook, Polymax datasheets (sulphur, peroxide, EP70), USGS sulfur 2026, PubChem GHS for ethylene, propylene and ethylidenenorbornene, Wikipedia EPDM and the Bencherif 2019 UV ageing paper, all read in this run. NASA outgassing rows were read from the rendered database but are not recorded as values.
story:
  recipe:
    line: EPDM is a terpolymer of ethylene, propylene and a diene. The diene (ethylidene norbornene, dicyclopentadiene or vinyl norbornene, about 2 to 12% in commercial grades per Wikipedia) carries the cure sites, so the rubber crosslinks by sulphur vulcanisation or by peroxide. Commercial compounds are filled with carbon black or mineral filler and extended with plasticisers. The UV-aged study used an aluminium trihydrate filled, peroxide-cured compound.
    parts:
      - name: Ethylene
        formula: C2H4
        share: not stated in the sources read
        role: Main monomer; with propylene it forms the saturated polyethylene-type backbone.
      - name: Propylene
        formula: C3H6
        share: not stated in the sources read
        role: Second main monomer; it breaks up the polyethylene crystallinity so the rubber stays elastic.
      - name: Diene
        formula: varies (ENB, DCPD or VNB)
        share: about 2 to 12% (Wikipedia)
        role: Cure site. Its double bonds take part in sulphur or peroxide crosslinking.
  risk_groups:
    - title: For people
      lead: No hazard classification was retrieved for the EPDM compound in this run.
      points:
        - label: Safety data
          line: Read the safety data sheet for the specific compound before handling. None was retrieved here.
    - title: For the monomers
      verdict: Flammable gases, and a flammable liquid diene
      lead: PubChem classifies the monomers, not the compound. Ethylene and propylene are extremely flammable gases under pressure. Ethylidene norbornene is a flammable liquid.
      points:
        - label: Ethylene
          line: Extremely flammable gas, which may explode if heated. PubChem also lists drowsiness or dizziness (H336).
        - label: Propylene
          line: Extremely flammable gas under pressure. PubChem lists the same H220 and H280 codes as ethylene.
        - label: Ethylidene norbornene
          line: Flammable liquid that may be fatal if swallowed and enters airways. PubChem also lists harm if inhaled and possible skin and eye irritation.
  why: EPDM is a rubber that stays elastic in hot water, steam and weather. Parker's handbook gives it up to 150 °C in water and steam and cold flexibility to about -57 °C, and says it is particularly useful in glycol and silicone brake fluids. It is weak in petroleum lubricants, which Parker says it deteriorates in.
  uses:
    - where: O-ring seals in brake systems
      line: Polymax says EPDM is particularly useful in brake systems with glycol (DOT 3 and 4) or silicone (DOT 5) fluids. Parker says it is useful with phosphate-ester hydraulic fluids.
    - where: Vacuum equipment O-rings and gaskets
      line: NASA's outgassing database lists EPDM O-rings and gaskets tested to ASTM E 595. Their values are not recorded in this file (see gaps). No spacecraft flight use was named.
  can_do:
    - label: Temperature
      value: '-30 to 150 °C'
      line: Polymax gives -30 to 125 °C for the sulphur-cured 70 ShA grade and -30 to 150 °C for the peroxide-cured grade. Parker gives up to 150 °C in water and steam, with special compounds to 260 °C in hot water and steam.
    - label: Cold
      value: '-57 °C'
      line: Parker gives cold flexibility down to about -57 °C. The peroxide-cured Polymax grade is rated to -42 °C by ISO 2921.
    - label: Hardness and strength
      value: 70 to 71 Shore A
      line: The 70 Shore A grades have a tensile strength of 10.5 to 17 MPa and an elongation of 220 to 255%.
    - label: Compression set
      value: 13 to 38%
      line: The peroxide-cured and EP70 grades keep 13% set after the test. The sulphur-cured grade keeps 38% after 22 h at 125 °C (ASTM D 395 B).
    - label: Outgassing
      value: Depends on part and bakeout
      line: NASA's database rows for EPDM O-rings differ before and after bakeout, and between manufacturers. The values are not recorded in this file because the database page loads them by script (see gaps).
  compare: EPDM is a general-purpose elastomer for hot water, steam, ozone and brake-fluid seals. Its best service is in water and steam, where Parker says ethylene propylene is generally superior to fluorocarbon. It is cold-flexible, but Parker says it deteriorates in petroleum lubricants. No comparison table with other elastomers was built in this run.
  compare_rows:
    - scope: material
      label: Operating range, upper limit
      benchmark: max_service_temp
    - scope: material
      label: Low-temperature limit
      benchmark: min_service_temp
    - scope: material
      label: Compression set
      benchmark: compression_set
  handling:
    - Read the product safety data sheet before use. None was retrieved in this run.
    - Do not lubricate with petroleum lubricants. Use silicone oil, glycerin or ethylene glycol, as Parker suggests.
    - Keep ethylene and propylene gases away from heat, since PubChem's H280 says they may explode if heated.
  good_for:
    - Hot water, steam and weathering seals, and brake-fluid seals in glycol or silicone fluids (Polymax and Parker).
    - 'Vacuum seals after bakeout: NASA''s database has ASTM E 595 rows for EPDM O-rings, and the rows differ before and after bakeout (values not recorded here, see gaps).'
    - Cold flexibility down to about -57 °C (Parker).
  watch_out:
    - 'Petroleum lubricants and oils: Parker says EPDM deteriorates in them.'
    - 'Heat ageing: 14% tensile loss and 24% elongation loss after 70 h at 125 °C (sulphur-cured grade).'
    - 'Compression set rises with heat: 38% after 22 h at 125 °C for the sulphur-cured grade, against 13% for the peroxide-cured grade.'
    - 'UV: a filled, peroxide-cured housing crosslinks and oxidises under UVA and its transition temperature moves from -42 °C to -37 °C after 2160 h.'
    - 'Radiation: at 10^7 rad, E0515-80 takes a 46.6% set (Parker).'
  verdict: EPDM is a dependable seal for hot water, steam, ozone and brake-fluid service. It does poorly in petroleum oils and lubricants, and its vacuum outgassing depends on the part and bakeout, so each seal needs a test or a verified NASA database row.