Nitrile rubber (NBR, Buna-N) NBR

spore: profile
id: nbr-nitrile
spore_version: 0.2
family: elastomers
name: Nitrile rubber (NBR, Buna-N)
abbreviation: NBR
role: Seal, O-ring and hose elastomer for oil, fuel and hydraulic service
category: seals-adhesives
type: elastomers-and-o-rings
summary: |
  Nitrile rubber (NBR, also called Buna-N) is a synthetic rubber derived from acrylonitrile and butadiene (Wikipedia). Two compound data sheets were read. A black, sulphur cross-linked 70 NBR compound from Freudenberg has a nominal hardness of 70 ±5 Shore A and a nominal tensile strength above 12 MPa. A black Parker compound has a hardness of 89 Shore A (specification 90 ±5) and a tensile strength of 2758 psi (ASTM D412). In Parker's test, the Parker compound's tensile strength changed by -56 % after 70 hours in IRM 903 oil at 257 °F.
best_for: Seals and O-rings in aliphatic hydrocarbon fuels, mineral oils, greases and HFA, HFB and HFC hydraulic fluids (Parker, Not Recommended list read)
weakest_at: Aromatic fuels, ketones, glycols, ozone and weathering. Parker lists these as not recommended, and the Parker compound's tensile strength changed by -56 % in IRM 903 oil at 257 °F.
identity:
  formula: Copolymer of acrylonitrile (ACN) and butadiene. Wikipedia gives the ratio as a grade choice, and says most applications needing both solvent resistance and low-temperature flexibility use an ACN content of 33 %.
  source: wikipedia-nitrile-rubber
  where: Lead section (definition of NBR as derived from acrylonitrile and butadiene); section on composition (ACN content of 33 %)
tags:
  environments: []
  stresses:
    - extreme-heat
    - extreme-cold
  applications:
    - mechanisms
    - propulsion-and-tanks
properties:
  - benchmark: hardness
    label: Hardness, Parker compound (ASTM D2240)
    value: 89
    unit: Shore A, pts
    scope: material
    conditions:
      compound: Parker compound, black, Parker report LTR 43883
      test: ASTM D2240
      specification: 90 ±5 as printed
    method: Test result printed in the Parker compound data sheet, original physical properties table
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Original Physical Properties, Hardness row
  - benchmark: hardness
    label: Hardness, FST 70 NBR S1OR71NB (DIN ISO 7619-1)
    value: 70
    unit: Shore A
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black, sulphur cross-linked
      test: DIN ISO 7619-1
      basis: nominal range printed as 70 ±5; the typical value column is blank
    method: Nominal range printed on the Freudenberg material data sheet; the sheet says values come from 2 mm laboratory sheets
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Physical Properties table, Hardness row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, Parker compound (ASTM D412)
    value: 2758
    unit: psi
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D412
      specification: 2500 minimum as printed
    method: Test result printed in the Parker compound data sheet, original physical properties table
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Original Physical Properties, Tensile Strength row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, FST 70 NBR S1OR71NB (ISO 37)
    value: 12
    bound: lower
    unit: MPa
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      test: ISO 37
      basis: nominal range printed as greater than 12 MPa; the typical value column is blank
    method: Nominal range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Physical Properties table, Tensile strength ISO 37 row
  - benchmark: elongation
    label: Ultimate elongation, Parker compound (ASTM D412)
    value: 103
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D412
      specification: 80 minimum as printed
    method: Test result printed in the Parker compound data sheet, original physical properties table
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Original Physical Properties, Ultimate Elongation row
  - benchmark: elongation
    label: Elongation at break, FST 70 NBR S1OR71NB (ISO 37)
    value: 250
    bound: lower
    unit: '%'
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      test: ISO 37
      basis: nominal range printed as greater than 250 %; the typical value column is blank
    method: Nominal range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Physical Properties table, Elongation at break ISO 37 row
  - benchmark: modulus_100_percent
    label: Modulus at 100 % elongation, Parker compound (ASTM D412)
    value: 2565
    unit: psi
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D412
      specification: report only, as printed
    method: Test result printed in the Parker compound data sheet, original physical properties table
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Original Physical Properties, Modulus at 100 % Elongation row
  - benchmark: specific_gravity
    label: Specific gravity, Parker compound (ASTM D297)
    value: 1.29
    unit: '-'
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D297
      specification: report only, as printed
      temperature: not printed
    method: Test result printed as specific gravity; not converted to a density
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Original Physical Properties, Specific Gravity row
  - benchmark: compression_set
    label: Compression set, 22 h at 257 °F (Parker compound, ASTM D395 method B)
    value: 18
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D395 method B
      time: 22 hours
      temperature: 257 °F
      basis: percent of original deflection, maximum, as printed
    method: Test result printed in the Parker compound data sheet, compression set block
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Compression Set, 22 hrs at 257 °F row
  - benchmark: compression_set
    label: Compression set, 22 h at 350 °F (Parker compound, ASTM D395 method B)
    value: 37
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      test: ASTM D395 method B
      time: 22 hours
      temperature: 350 °F
      basis: percent of original deflection, maximum, as printed
    method: Test result printed in the Parker compound data sheet, compression set block
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, Compression Set, 22 hrs at 350 °F row
  - benchmark: compression_set
    label: Compression set, 72 h at 100 °C (FST 70 NBR, DIN ISO 815 method B)
    value: 40
    bound: upper
    unit: '%'
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      test: DIN ISO 815, method B
      time: 72 hours
      temperature: 100 °C
      basis: nominal range printed as less than 40 %; the typical value column is blank
    method: Nominal range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Physical Properties table, Compression set row
  - benchmark: low_temperature_tr10
    label: Low temperature, TR10 (FST 70 NBR S1OR71NB, ISO 2921)
    value: -20
    bound: upper
    unit: °C
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      test: ISO 2921, TR10
      basis: nominal range printed as less than -20 °C
    method: Nominal range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Physical Properties table, Low temperature ISO 2921 TR10 row
  - benchmark: max_service_temp
    label: Recommended upper temperature, Parker compound
    value: 275
    unit: °F
    scope: material
    conditions:
      compound: Parker compound, black
      basis: recommended temperature range printed in the report, not a test limit
    method: Recommended range printed in the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 1 of 2, Recommended Temperature Range row
  - benchmark: min_service_temp
    label: Recommended lower temperature, Parker compound
    value: -30
    unit: °F
    scope: material
    conditions:
      compound: Parker compound, black
      basis: recommended temperature range printed in the report, not a test limit
    method: Recommended range printed in the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 1 of 2, Recommended Temperature Range row
  - benchmark: max_service_temp
    label: Static temperature range, upper limit, FST 70 NBR S1OR71NB
    value: 100
    unit: °C
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      basis: static use, as printed in the Temperature Range block
    method: Range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Temperature Range, static row
  - benchmark: min_service_temp
    label: Static temperature range, lower limit, FST 70 NBR S1OR71NB
    value: -30
    unit: °C
    scope: material
    conditions:
      compound: 70 NBR S1OR71NB, black
      basis: static use, as printed in the Temperature Range block
    method: Range printed on the Freudenberg material data sheet
    status: ground
    source: fst-nbr-70
    where: Page 1 of 3, Temperature Range, static row
  - benchmark: fluid_tensile_strength_change
    label: Tensile strength change after IRM 903 oil, Parker compound
    value: -56
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      fluid: IRM 903
      time: 70 hours
      temperature: 257 °F
    method: Change printed in the IRM 903 block of the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, IRM 903 block, Tensile Strength Change row
  - benchmark: fluid_ultimate_elongation_change
    label: Ultimate elongation change after IRM 903 oil, Parker compound
    value: -31
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      fluid: IRM 903
      time: 70 hours
      temperature: 257 °F
    method: Change printed in the IRM 903 block of the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, IRM 903 block, Ultimate Elongation Change row
  - benchmark: fluid_volume_change
    label: Volume change after IRM 903 oil, Parker compound
    value: 10
    unit: '%'
    scope: material
    conditions:
      compound: Parker compound, black
      fluid: IRM 903
      time: 70 hours
      temperature: 257 °F
      sign_as_printed: '+10'
    method: Change printed in the IRM 903 block of the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, IRM 903 block, Volume Change row
  - benchmark: fluid_hardness_change
    label: Hardness change after IRM 903 oil, Parker compound (ASTM D471)
    value: -2
    unit: pts
    scope: material
    conditions:
      compound: Parker compound, black
      fluid: IRM 903
      test: ASTM D471
      time: 70 hours
      temperature: 257 °F
    method: Change printed in the IRM 903 block of the Parker compound data sheet
    status: ground
    source: parker-ltr-43883
    where: Page 2 of 2, IRM 903 block, Hardness Change row
corrosion:
  - environment: Immersion in IRM 903 oil, 70 hours at 257 °F (Parker compound)
    headline: In IRM 903 oil at 257 °F for 70 hours, the Parker compound's tensile strength changed by -56 % and its elongation by -31 %.
    effect: The same test gave a volume change of +10 % and a hardness change of -2 pts. The report gives these changes for one compound and one oil only; it gives no service life.
    rating: severe
    conditions:
      fluid: IRM 903 oil
      time: 70 hours
      temperature: 257 °F
      test: ASTM D471 (as printed on the hardness-change row)
    source: parker-ltr-43883
    where: Page 2 of 2, IRM 903 block
  - environment: Aromatic hydrocarbons, benzene, chlorinated solvents, strong acids, glycols, ketones and other polar solvents
    headline: Parker lists these fluids as not recommended for this NBR compound.
    effect: The Not Recommended For block lists fuels of high aromatic content, aromatic hydrocarbons (benzene), chlorinated hydrocarbons (trichloroethylene), strong acids, glycols and polar solvents (ketone, acetone, acetic acid, ethylene-ester). No test result for any of these fluids is printed on the report.
    rating: unknown
    conditions:
      basis: list in the Parker report; no test data for these fluids
    source: parker-ltr-43883
    where: Page 1 of 2, Not Recommended For block
  - environment: Ozone, weather and atmospheric ageing
    headline: Parker lists ozone, weather and atmospheric ageing as not recommended for this compound.
    effect: Neither data sheet prints an ozone or weathering result. The Parker list is the only statement about these exposures in the sources read.
    rating: unknown
    conditions:
      basis: list statement in the Parker report; no test result
    source: parker-ltr-43883
    where: Page 1 of 2, Not Recommended For block
  - environment: Mineral oils, aliphatic hydrocarbon fuels, vegetable oils, salt and alkali solutions, dilute acids, and HFA, HFB and HFC hydraulic fluids
    headline: Parker lists these as recommended for this NBR compound; no test result is printed for them.
    effect: The Recommended For block names aliphatic hydrocarbons (propane, butane, petroleum oil, mineral oil and grease, diesel fuel, fuel oils), vegetable oils, mineral oils, greases, HFA, HFB and HFC hydraulic fluids, salt and alkali solutions, and dilute acids.
    rating: low
    conditions:
      basis: recommendation statement in the Parker report
    source: parker-ltr-43883
    where: Page 1 of 2, Recommended For block
  - environment: General NBR in oil, fuel and other chemicals across its stability range
    headline: Wikipedia says NBR is resistant to oil, fuel and other chemicals, and gives its stability range as -40 to 108 °C.
    effect: The article states that NBR is unusual in being resistant to oil, fuel and other chemicals, and gives its stability range as -40 to 108 °C. It names no grade or test conditions, so the range is a general statement about NBR and not a rating for the compounds above.
    rating: unknown
    conditions:
      basis: general statement in the article; no test condition given
    source: wikipedia-nitrile-rubber
    where: Section on temperature range and oil resistance
risks:
  hazards:
    - text: 'Monomer acrylonitrile (PubChem CID 7855, ECHA aggregate): signal word "Danger". The most-notified statements are "Highly Flammable liquid and vapor" (H225), "Toxic if swallowed" (H301), "Toxic in contact with skin" (H311), "Causes serious eye damage" (H318), "Toxic if inhaled" (H331) and "May cause cancer" (H350). NBR itself was not classified in any source read.'
      ghs:
        - H225
        - H301
        - H311
        - H318
        - H331
        - H350
      source: pubchem-acrylonitrile
      where: Safety and Hazards, GHS Classification (CID 7855), ECHA aggregate block
    - text: 'Monomer 1,3-butadiene (PubChem CID 7845, ECHA aggregate): signal word "Danger". The statements are "Extremely flammable gas" (H220), "Contains gas under pressure; may explode if heated" (H280), "May cause genetic defects" (H340) and "May cause cancer" (H350). NBR itself was not classified in any source read.'
      ghs:
        - H220
        - H280
        - H340
        - H350
      source: pubchem-butadiene
      where: Safety and Hazards, GHS Classification (CID 7845), ECHA aggregate block
    - text: 'Acrylonitrile exposure limits (NIOSH Pocket Guide, CAS 107-13-1): the NIOSH REL is "Ca TWA 1 ppm C 10 ppm [15-minute] [skin]" and the IDLH is "Ca [60 ppm]". Exposure routes are "inhalation, skin absorption, ingestion, skin and/or eye contact". Target organs are "Eyes, skin, cardiovascular system, liver, kidneys, central nervous system".'
      ghs: []
      source: niosh-acrylonitrile
      where: Exposure limits, IDLH, Exposure routes and Health hazards blocks of Pocket Guide entry npgd0014
    - text: 'Acrylonitrile regulation (ATSDR Toxicological Profile, Table 7-1): the HHS carcinogenicity classification is "Reasonably anticipated to be a human carcinogen", and the OSHA PEL (8-hour TWA) for general industry is "2 ppm".'
      ghs: []
      source: atsdr-acrylonitrile
      where: Chapter 7, Table 7-1, Carcinogenicity and Occupational rows
  failure_risks:
    - mode: Swelling and strength loss in aromatic or polar fluids
      trigger: Exposure to high-aromatic fuels, benzene, ketones or other polar solvents, which Parker lists as not recommended
      consequence: No test result is printed for these fluids. In IRM 903 oil at 257 °F for 70 hours, the Parker compound's tensile strength changed by -56 % and its volume by +10 %.
      severity: high
      source: parker-ltr-43883
      where: Not Recommended For block; IRM 903 block
    - mode: Ageing from ozone and weather
      trigger: Ozone, weather and atmospheric exposure
      consequence: Parker lists these as not recommended. No ageing result is printed in either data sheet.
      severity: moderate
      source: parker-ltr-43883
      where: Not Recommended For block
    - mode: Permanent set after heat exposure
      trigger: 'Compression under heat: 22 hours at 257 °F, 22 hours at 350 °F, or 72 hours at 100 °C'
      consequence: The Parker compound took a permanent set of 18 % at 257 °F and 37 % at 350 °F (ASTM D395 method B). The FST 70 NBR nominal limit is less than 40 % at 72 hours and 100 °C.
      severity: moderate
      source: parker-ltr-43883
      where: Page 2 of 2, Compression Set rows
  side_effects: []
  handling: []
  mitigations:
    - text: 'Keep service within the recommended range printed by each source: -30 to 275 °F for the Parker compound, and -30 to 100 °C static for the FST 70 NBR compound.'
      source: parker-ltr-43883
      where: Page 1 of 2, Recommended Temperature Range; FST Temperature Range block
uses:
  - application: propulsion-and-tanks
    device: Seals for fuel and oil handling
    example: Parker lists aliphatic hydrocarbons such as propane, butane, petroleum oil, diesel fuel and fuel oils as recommended for this NBR compound. Wikipedia names fuel and oil handling hoses, seals, grommets and self-sealing fuel tanks as NBR uses.
    source: parker-ltr-43883
    where: Recommended For block, page 1 of 2
  - application: mechanisms
    device: O-ring seals in hydraulic and grease-lubricated mechanisms
    example: Parker lists mineral oils, greases, and HFA, HFB and HFC hydraulic fluids as recommended for this compound.
    source: parker-ltr-43883
    where: Recommended For block, page 1 of 2
  - application: mechanisms
    device: Fluid power O-rings (nominal ranges set against ISO 3601-5)
    example: The FST 70 NBR data sheet gives its nominal ranges on the basis of ISO 3601-5, the specification for elastomeric O-ring materials in industrial fluid power, and lists a static range of -30 to 100 °C.
    source: fst-nbr-70
    where: Page 1 of 3, note below the Physical Properties table; Temperature Range block
  - application: propulsion-and-tanks
    device: Self-sealing fuel tanks and fuel lines
    example: Wikipedia names self-sealing fuel tanks among the automotive and aeronautical uses of NBR, with hoses, seals and grommets.
    source: wikipedia-nitrile-rubber
    where: Section on applications (automotive and aeronautical)
supply:
  - subject: Nitrile rubber (NBR), ARLANXEO-TSRC plant
    producers:
      - country: China
        year: 2025
    critical_lists: []
    substitutes: []
    source: arlanxeo-nantong-2025
    where: 'Nantong, Jiangsu Province, China: ARLANXEO-TSRC (Nantong) Chemical Industrial Co. Ltd., a joint venture, press release dated May 16, 2025. Designed capacity increased to 40,000 tons per annum. No share of world output was printed.'
  - subject: Nitrile rubber (NBR), Zeon Tokuyama plant
    producers:
      - country: Japan
        year: 2010
    critical_lists: []
    substitutes: []
    source: zeon-tokuyama-2010
    where: 'Tokuyama, Japan: Zeon Corp. NBR capacity raised to 55,000 metric tons a year from 45,000 tons, article dated 21 Jan 2010. The article is dated, and the current capacity was not read.'
documents:
  - title: 'Parker O-Ring Division, Compound Data Sheet: Evaluation of Parker Compound, Material Report LTR 43883 (2006)'
    type: datasheet
    url: https://www.marcorubber.com/downloads/Marco-Material-Datasheet-Parker-NB194-90.pdf
    year: 2006
  - title: Freudenberg Industrial Services, Material data sheet 70 NBR S1OR71NB, version 08
    type: datasheet
    url: https://products.fst.com/medialibrary/materialdatasheets/70%20NBR%20S1OR71NB_en.pdf
    year: 2026
  - title: NIST Atomic Weights and Isotopic Compositions for All Elements (N, C and H)
    type: database
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=N&all=all&ascii=html
    year: 2026
  - title: PubChem, Acrylonitrile (CID 7855), Safety and Hazards, GHS Classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/7855/JSON?heading=GHS+Classification
  - title: PubChem, 1,3-Butadiene (CID 7845), Safety and Hazards, GHS Classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/7845/JSON?heading=GHS+Classification
  - title: NIOSH Pocket Guide to Chemical Hazards, Acrylonitrile (npgd0014)
    type: report
    url: https://www.cdc.gov/niosh/npg/npgd0014.html
  - title: ATSDR Toxicological Profile for Acrylonitrile, Chapter 7 (Regulations and Guidelines)
    type: report
    url: https://www.atsdr.cdc.gov/toxprofiles/tp125-c7.pdf
gaps:
  - No CAS number, UNS, EN, DIN, ASTM or trade-name designation was printed for this NBR grade in any source read in this run, so designations are empty.
  - No world production share, USGS entry or critical-mineral entry for NBR, acrylonitrile or butadiene was read. Supply lists two producer plants with printed capacities, from a 2025 manufacturer press release and a 2010 trade article; these are not a market share.
  - No GHS classification or safety data sheet for NBR itself was read. The hazard entries use PubChem's GHS aggregate and the NIOSH and ATSDR entries for the monomers acrylonitrile and 1,3-butadiene, and say so; they are not hazard data for NBR.
  - A CDC IDLH page that appeared in search gave a different IDLH for acrylonitrile (85 ppm). That page was not fetched, so the value is not recorded; the NIOSH entry read gives Ca [60 ppm].
  - No handling, storage or dust guidance was read for NBR, so risks.handling is empty.
  - No outgassing (total mass loss, collected volatile condensable material) or vacuum, radiation, atomic oxygen or thermal-cycling data for NBR was read in this run.
  - No glass transition temperature, density of a named grade, or heat-ageing retention of tensile strength or elongation was printed in the sources read. Wikipedia gives a general compounded density of about 1.00 g/cm3 without a grade or test method; it is not recorded.
  - The Parker and Freudenberg compounds are different products with different test methods, so their values are not directly comparable. The Parker recommended range (-30 to 275 °F) and the FST static range (-30 to 100 °C) are both recorded, and they are not reconciled.
  - No FKM, EPDM or silicone comparison values were read in this run, so the compare paragraph is qualitative.
  - 'Property names not in property-canon.yaml: hardness, compression_set, modulus_100_percent, low_temperature_tr10, fluid_tensile_strength_change, fluid_ultimate_elongation_change, fluid_volume_change and fluid_hardness_change. Shore A hardness and ISO 37 results are kept under the names printed in each source.'
  - The PubChem record for nitrile rubber itself returned a captcha page, so no PubChem entry for NBR is cited. The sources are listed under sources; the NBR-specific data come from the two compound data sheets and Wikipedia.
  - No image or media file is attached to this profile.
sources:
  parker-ltr-43883:
    title: 'Compound Data Sheet: Evaluation of Parker Compound, Material Report LTR 43883'
    id: Parker O-Ring Division LTR Report Number 43883, dated 10/3/2006
    url: https://www.marcorubber.com/downloads/Marco-Material-Datasheet-Parker-NB194-90.pdf
    year: 2006
    kind: datasheet
    license: manufacturer data sheet, linked not reproduced
  fst-nbr-70:
    title: Freudenberg Industrial Services material data sheet, 70 NBR S1OR71NB
    id: Version 08, released 03.06.2026; print date 23.06.2026
    url: https://products.fst.com/medialibrary/materialdatasheets/70%20NBR%20S1OR71NB_en.pdf
    year: 2026
    kind: datasheet
    license: supplier data sheet, linked not reproduced
  wikipedia-nitrile-rubber:
    title: Nitrile rubber, Wikipedia
    id: Lead, composition, applications and temperature range sections
    url: https://en.wikipedia.org/wiki/Nitrile_rubber
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  nist-atomic-weights:
    title: NIST Atomic Weights and Isotopic Compositions for All Elements (N, C and H rows)
    id: 'NIST standard atomic weights: C [12.0096, 12.0116]; H [1.007 84, 1.008 11]; N [14.006 43, 14.007 28]'
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=N&all=all&ascii=html
    kind: database
    license: US government data
  pubchem-acrylonitrile:
    title: PubChem, Acrylonitrile (CID 7855), Safety and Hazards, GHS Classification
    id: PubChem CID 7855, ECHA aggregated GHS classification block
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/7855/JSON?heading=GHS+Classification
    kind: database
    license: US government database, linked not reproduced
  pubchem-butadiene:
    title: PubChem, 1,3-Butadiene (CID 7845), Safety and Hazards, GHS Classification
    id: PubChem CID 7845, ECHA aggregate GHS classification
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/7845/JSON?heading=GHS+Classification
    kind: database
    license: US government database, linked not reproduced
  niosh-acrylonitrile:
    title: NIOSH Pocket Guide to Chemical Hazards, Acrylonitrile (CAS 107-13-1)
    id: NIOSH Pocket Guide entry npgd0014
    url: https://www.cdc.gov/niosh/npg/npgd0014.html
    kind: handbook
    license: US government publication
  atsdr-acrylonitrile:
    title: ATSDR Toxicological Profile for Acrylonitrile, Chapter 7 (Regulations and Guidelines), Table 7-1
    id: ATSDR tp125, chapter 7, pages 127 and 128
    url: https://www.atsdr.cdc.gov/toxprofiles/tp125-c7.pdf
    kind: report
    license: US government publication
  arlanxeo-nantong-2025:
    title: ARLANXEO and TSRC announce the inauguration of their new joint venture NBR plant in Nantong (press release)
    id: Press release, Nantong, May 16, 2025
    url: https://www.arlanxeo.com/en/news-media/press-releases/ARLANXEO-and-TSRC-announce-the-inauguration-of-their-new-joint-venture-NBR-plant-in-Nantong
    year: 2025
    kind: web
    license: manufacturer press release, linked not reproduced
  zeon-tokuyama-2010:
    title: European Rubber Journal, Zeon to add nitrile capacity in Japan
    id: Article dated 21 Jan 2010
    url: http://www.european-rubber-journal.com/article/2080388/zeon-to-add-nitrile-capacity-in-japan
    year: 2010
    kind: web
    license: trade article, linked not reproduced
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 20
  unreachable: 2
  caveats: 3
  note: 'Read by an AI assistant on 2026-11-01 from the Parker LTR 43883 data sheet, the Freudenberg 70 NBR S1OR71NB data sheet, the Wikipedia article and NIST atomic weights. Unreachable: PubChem nitrile rubber record (captcha) and a Parker O-ring handbook URL that was not a PDF. Caveats: the Parker values are for one black compound with no test standard printed for some rows; the FST values are nominal ranges from 2 mm laboratory sheets; the recommended temperature ranges are not test limits.'
story:
  recipe:
    line: Nitrile rubber is a copolymer of acrylonitrile and butadiene. Wikipedia says water serves as the reaction medium in the production vessel. The FST 70 NBR S1OR71NB compound is sulphur cross-linked, as its data sheet prints under Type of cross-linking. The acrylonitrile content sets the balance between oil resistance and low-temperature flexibility; Wikipedia gives 33 % as the figure for most applications that need both.
    parts:
      - name: Carbon
        symbol: C
        role: The carbon backbone of both monomers, acrylonitrile and butadiene.
        share_note: atomic_weight [12.0096, 12.0116]
      - name: Hydrogen
        symbol: H
        role: Hydrogen on the butadiene and acrylonitrile units; the rubber has a hydrocarbon backbone.
        share_note: atomic_weight [1.007 84, 1.008 11]
      - name: Nitrogen
        symbol: 'N'
        role: Carried by the nitrile group (C≡N) of the acrylonitrile units. More acrylonitrile raises oil resistance and stiffens the rubber at low temperature.
        share_note: atomic_weight [14.006 43, 14.007 28]
  risk_groups:
    - title: For people
      level: 0
      verdict: Monomer hazards only
      lead: No safety data sheet for NBR itself was read, so the points below are for the two monomers it is made from, acrylonitrile and 1,3-butadiene.
      points:
        - label: Acrylonitrile
          line: PubChem ECHA aggregate gives the signal word "Danger" and lists toxic if swallowed, toxic in contact with skin, toxic if inhaled, causes serious eye damage and may cause cancer. NIOSH gives the REL as "Ca TWA 1 ppm C 10 ppm [15-minute] [skin]".
        - label: 1,3-butadiene
          line: PubChem ECHA aggregate gives the signal word "Danger" and lists extremely flammable gas, may cause genetic defects and may cause cancer.
    - title: If it fails
      lead: The failure routes in these sources are fluid attack, ozone and weathering, and heat-set. Each is tied to a printed result or a printed Parker limit.
      points:
        - label: Aromatic and polar fluids
          line: Parker lists high-aromatic fuels, benzene, ketones and similar solvents as not recommended. In IRM 903 oil at 257 °F for 70 hours, the Parker compound's tensile strength changed by -56 % and its elongation by -31 %.
        - label: Ozone and weather
          line: Parker lists ozone, weather and atmospheric ageing as not recommended. No ageing result is printed.
        - label: Heat set
          line: The Parker compound took a permanent set of 18 % after 22 hours at 257 °F and 37 % after 22 hours at 350 °F.
  why: Nitrile rubber (NBR, Buna-N) is a synthetic rubber derived from acrylonitrile and butadiene. Its acrylonitrile content sets the balance between oil and fuel resistance and low-temperature flexibility. Two compound data sheets read for this profile show the rubber is used where oils and fuels must be sealed. Wikipedia names fuel and oil handling hoses, seals, grommets and self-sealing fuel tanks as its main automotive and aeronautical uses.
  uses:
    - where: Fuel and oil seals
      line: Parker lists aliphatic hydrocarbons, including propane, butane, petroleum oil, diesel fuel and fuel oils, as recommended for its black NBR compound.
    - where: Hydraulic and grease service
      line: The same report lists mineral oils, greases and HFA, HFB and HFC hydraulic fluids as recommended. The FST 70 NBR data sheet gives nominal ranges on the basis of ISO 3601-5, the specification for elastomeric O-ring materials in industrial fluid power.
    - where: Fuel tanks and hoses
      line: Wikipedia says NBR is used for fuel and oil handling hoses, seals, grommets and self-sealing fuel tanks.
  can_do:
    - label: Hardness
      benchmark: hardness
      value: 89 Shore A (Parker compound), 70 ±5 Shore A (FST nominal)
      line: The Parker compound measured 89 Shore A against a specification of 90 ±5 (ASTM D2240). The FST 70 NBR S1OR71NB has a nominal hardness of 70 ±5 Shore A (DIN ISO 7619-1).
    - label: Strength
      benchmark: ultimate_tensile_strength
      value: 2758 psi (Parker compound)
      line: The Parker compound's tensile strength is 2758 psi (ASTM D412), against a minimum of 2500 psi. The FST compound's nominal tensile strength is above 12 MPa (ISO 37).
    - label: Low temperature
      benchmark: low_temperature_tr10
      value: less than -20 °C (TR10)
      line: The FST 70 NBR compound's nominal TR10 low-temperature value is less than -20 °C (ISO 2921).
    - label: Oil resistance
      benchmark: fluid_tensile_strength_change
      value: '-56 % in IRM 903 oil'
      line: After 70 hours in IRM 903 oil at 257 °F, the Parker compound's tensile strength changed by -56 %, its elongation by -31 % and its volume by +10 %.
  compare: NBR is used where aliphatic fuels, mineral oils and hydraulic fluids must be sealed, and the two data sheets read here show a recommended upper limit of 275 °F for the Parker compound and 100 °C static for the FST compound. Parker's list shows that NBR is not recommended for aromatic fuels, ketones and ozone, so an oil-resistant seal in those services needs a different elastomer; this profile does not read a comparison value for the other elastomers in the set.
  compare_rows:
    - label: Hardness
      benchmark: hardness
    - label: Tensile strength
      benchmark: ultimate_tensile_strength
    - label: Upper service temperature
      benchmark: max_service_temp
  handling:
    - Confirm the grade and compound with the supplier before use, since the Parker and FST compounds differ in their limits.
    - 'Keep service within the printed range: -30 to 275 °F for the Parker compound, and -30 to 100 °C static for the FST compound.'
    - Do not use NBR in aromatic fuels, ketones or outdoors in ozone and weather, since Parker lists these as not recommended.
  good_for:
    - 'Oil and fuel seals: Parker lists aliphatic fuels, mineral oils, greases and HFA, HFB and HFC hydraulic fluids as recommended.'
    - 'Fluid power O-rings: FST gives nominal ranges on the basis of ISO 3601-5.'
    - 'Hardness control: the two compounds read sit at 70 and 89 Shore A, against a specification of 90 ±5 for the Parker compound.'
  watch_out:
    - 'Aromatic fuels, benzene, ketones and polar solvents: Parker lists these as not recommended, with no test result printed.'
    - 'Ozone and weather: Parker lists these as not recommended for atmospheric ageing.'
    - 'Heat set: 18 % after 22 hours at 257 °F and 37 % after 22 hours at 350 °F for the Parker compound.'
    - No outgassing or radiation data for NBR were read, so this profile gives no space-vacuum result.
  verdict: NBR suits seals in aliphatic fuels, mineral oils and hydraulic fluids, and both data sheets read here give a clear operating range. The sources read do not cover ozone, weathering or space exposure, so those limits are not recorded as values.