Fomblin Y LVAC perfluoropolyether vacuum pump fluid PFPE

spore: profile
id: fomblin-y-lvac
spore_version: 0.2
family: perfluoropolyethers
name: Fomblin Y LVAC perfluoropolyether vacuum pump fluid
abbreviation: PFPE
role: vacuum pump lubricant and sealing fluid
category: tribology
type: liquid-lubricants
summary: |
  Fomblin Y LVAC is a perfluorinated polyether (PFPE) liquid used as the sealing and lubricating fluid in mechanical vacuum pumps. The 25/6 grade has a density of 1.9 g/cm3 and a kinematic viscosity of 276 cSt at 20 °C per the manufacturer's datasheet, which lists low vapor pressure as a feature. The fluid is not classified as hazardous under the US hazard communication standard, but it decomposes above 290 °C into hydrogen fluoride.
best_for: 'Mechanical vacuum pumps where a low vapour pressure matters: the Syensqo datasheet lists low vapor pressure as a feature of the 25/6 grade'
weakest_at: 'Heat and metals: the SDS says decomposition starts above 290 °C and that metals lower that temperature, and no outgassing or space flight test was found'
identity:
  formula: Perfluorinated polyether (PFPE), a fluorinated polymer built only of carbon, fluorine and oxygen, made from hexafluoropropylene (named in the SDS as 1-Propene, 1,1,2,3,3,3-hexafluoro-, oxidized, polymd.)
  cas: 69991-67-9
  source: solvay-sds-2014
  where: Section 3.1 Substances, CAS-No. 69991-67-9 row (more than 99.9 %). The chemical nature line reads 'Perfluorinated polyethers'.
tags:
  stresses:
    - vacuum-and-outgassing
  applications:
    - mechanisms
    - electronics-and-chips
properties:
  - benchmark: density
    label: Density of the 25/6 grade
    value: 1.9
    unit: g/cm3
    scope: material
    conditions:
      grade: 25/6
      temperature: 20 °C
      test: ASTM D4052
      unit_in_source: g/cm³
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Density (20°C)
  - benchmark: average_molecular_weight
    label: Average molecular weight of the 25/6 grade
    value: 3300
    unit: amu
    scope: material
    conditions:
      grade: 25/6
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Average Molecular Weight
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity of the 25/6 grade
    value: 276
    unit: cSt
    scope: material
    conditions:
      grade: 25/6
      temperature: 20 °C
      test: ASTM D445
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Kinematic Viscosity (20°C)
  - benchmark: viscosity_index
    label: Viscosity index of the 25/6 grade
    value: 113
    unit: '-'
    scope: material
    conditions:
      grade: 25/6
      test: ASTM D2270
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Viscosity Index
  - benchmark: pour_point
    label: Pour point of the 25/6 grade
    value: -35
    unit: °C
    scope: material
    conditions:
      grade: 25/6
      test: ASTM D97
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Thermal table, row Pour Point
  - benchmark: surface_tension
    label: Surface tension of the 25/6 grade
    value: 22
    unit: dyne/cm
    scope: material
    conditions:
      grade: 25/6
      temperature: 20 °C
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Surface Tension (20°C)
  - benchmark: heat_of_vaporization
    label: Heat of vaporization of the 25/6 grade
    value: 7
    unit: cal/g
    scope: material
    conditions:
      grade: 25/6
      temperature: 200 °C
      printed_as: 7.00 cal/g
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Thermal table, row Heat of Vaporization (200°C)
  - benchmark: evaporation_loss
    label: Evaporation weight loss of the 25/6 grade
    value: 0.6
    unit: wt%
    scope: material
    conditions:
      grade: 25/6
      temperature: 149 °C
      time: 22 h
    method: Typical value printed in a manufacturer technical data sheet
    status: ground
    source: syensqo-tds-25-6
    where: Physical table, row Evaporation Weight Loss - 22 hrs (149°C)
  - benchmark: boiling_point
    label: Boiling point of the Fomblin Y LVAC product family
    value: 270
    unit: °C
    scope: material
    conditions:
      grades: 06/6; 14/6; 16/6; 25/6; 300 (grades named in the SDS)
      printed_as: '> 270 °C (518 °F)'
    method: Printed by the manufacturer's safety data sheet as a lower bound ('greater than'), not as a measured point
    status: ground
    source: solvay-sds-2014
    where: Section 9.2, Boiling point/boiling range
  - benchmark: decomposition_temperature
    label: Decomposition temperature of the Fomblin Y LVAC product family
    value: 290
    unit: °C
    scope: material
    conditions:
      grades: 06/6; 14/6; 16/6; 25/6; 300 (grades named in the SDS)
      printed_as: '> 290 °C (554 °F)'
      atmosphere: not stated
      time: not stated
    method: Printed by the manufacturer's safety data sheet as a lower bound ('greater than'); no test method is given
    status: ground
    source: solvay-sds-2014
    where: Section 9.3, Other data, Decomposition temperature
  - benchmark: average_molecular_weight
    label: Average molecular weight range of the Fomblin Y LVAC product family
    value: 1800
    value_high: 3300
    unit: amu
    scope: material
    conditions:
      grades: 06/6; 14/6; 16/6; 25/6; 300 (grades named in the SDS)
      printed_as: 1,800 - 3,300
    method: Range printed in the manufacturer's safety data sheet for the product family, not a value for one grade
    status: ground
    source: solvay-sds-2014
    where: Section 1.1, Molecular weight, Range of values
  - benchmark: dynamic_viscosity
    label: Dynamic viscosity range of the Fomblin Y LVAC product family at 20 °C
    value: 95
    value_high: 560
    unit: mPa.s
    scope: material
    conditions:
      temperature: 20 °C
      grades: 06/6; 14/6; 16/6; 25/6; 300 (grades named in the SDS)
      printed_as: ca. 95 - 560 mPa.s
    method: Approximate range printed in the manufacturer's safety data sheet; the test method is not printed
    status: ground
    source: solvay-sds-2014
    where: Section 9.2, Viscosity
  - benchmark: specific_gravity
    label: Specific gravity range of the Fomblin Y/LVAC series at 20 °C
    value: 1.84
    value_high: 1.93
    unit: '-'
    scope: material
    conditions:
      temperature: 20 °C
      grades: 06/6, 14/6, 16/6, 25/6 and 25/9 (grades named in the Edwards SDS)
      printed_as: 1.84 - 1.93 @ 20oC/68o F
    method: Range printed in the BOC Edwards safety data sheet for the series; the test method is not printed
    status: ground
    source: bocedwards-sds
    where: Section 9, Physical and Chemical Properties, Specific Gravity
corrosion:
  - environment: Lewis acids and metals at high temperature
    headline: Above 100 °C, Lewis acids and metals lower the temperature at which the fluid breaks down.
    effect: The SDS says to avoid Lewis acids (Friedel-Crafts) such as AlCl3, SbF5 and CoF3 above 100 °C, and aluminium and magnesium powder above 200 °C. It also says metals promote and lower the decomposition temperature. No corrosion rate or metal test is given.
    rating: moderate
    conditions:
      temperature: above 100 °C for Lewis acids; above 200 °C for aluminium and magnesium powder
    source: solvay-sds-2014
    where: Section 10.3, Materials to avoid
  - environment: Metals, plastics and elastomers in contact with the fluid at normal temperature
    headline: The datasheet lists compatibility with metals, plastics and elastomers as a feature. It does not print a test result.
    effect: The Syensqo datasheet lists 'Excellent compatibility with metals, plastics, elastomers' among the features of the Y LVAC line. The datasheet gives no test method, exposure time or measured change for any material.
    rating: unknown
    conditions:
      basis: feature list in a manufacturer datasheet; no test conditions printed
    source: syensqo-tds-25-6
    where: Features list, first page
  - environment: Thermal breakdown above 290 °C
    headline: Above 290 °C the fluid breaks down and releases hydrogen fluoride, a corrosive gas.
    effect: The Edwards SDS says the product may decompose above 290 °C with emissions of hydrogen fluoride and carbonyl fluoride, which are toxic and corrosive. The Solvay 2014 SDS lists the same hydrogen fluoride and names fluorophosgene as a product too. No rate of decomposition is given.
    rating: severe
    conditions:
      temperature: above 290 °C
      atmosphere: not stated
    source: bocedwards-sds
    where: Section 10, Hazardous Decomposition; Solvay 2014 SDS section 10.4
risks:
  hazards:
    - text: The Solvay safety data sheet for Fomblin Y LVAC is not classified according to the US hazard communication standard (HCS 2012). It has no label elements.
      ghs: []
      source: solvay-sds-2014
      where: Sections 2.1 and 2.2
    - text: The Edwards sheet says that when properly handled the material is not dangerous to human health or the environment. It also says vapours that may irritate the respiratory system can be released above 290 °C (554 °F).
      ghs: []
      source: bocedwards-sds
      where: Section 3, Emergency Overview
    - text: Solvay's safety data sheet gives an acute oral LD50 in rat of more than 15,000 mg/kg, an acute dermal LD50 in rat of more than 5,000 mg/kg, and no skin or eye irritation in rabbits.
      ghs: []
      source: solvay-sds-2014
      where: Section 11.1 (acute toxicity), Sections 11.2 and 11.3
  failure_risks:
    - mode: Thermal decomposition of the fluid
      trigger: Heating above 290 °C, or contact with free flames, which the SDS says to avoid
      consequence: Releases hydrogen fluoride and carbonyl fluoride (Edwards SDS) or hydrogen fluoride and fluorophosgene (Solvay 2014 SDS). These gases are toxic and corrosive.
      severity: high
      source: bocedwards-sds
      where: Section 10, Hazardous Decomposition
    - mode: Breakdown catalysed by metals and Lewis acids
      trigger: Lewis acids above 100 °C, or aluminium and magnesium powder above 200 °C
      consequence: The SDS says metals promote and lower the decomposition temperature. The lowered temperature is not quantified in any source read.
      severity: moderate
      source: solvay-sds-2014
      where: Section 10.3, Materials to avoid
  side_effects: []
  handling:
    - text: Avoid heating above the decomposition temperature of 290 °C (554 °F). Keep away from heat and sources of ignition.
      source: bocedwards-sds
      where: Section 7, Handling and Storage
    - text: Store in glass or polyethylene containers. The Solvay 2014 SDS lists polyethylene as the packaging material.
      source: bocedwards-sds
      where: Section 7, Handling and Storage; Solvay 2014 SDS section 7.3
    - text: Take measures to prevent the build-up of electrostatic charge, and ensure equipment is electrically grounded before transfer operations.
      source: solvay-sds-2014
      where: Section 7.1, Handling
    - text: In a thermal decomposition, wear self-contained breathing apparatus, and wear rubber gloves and safety goggles for handling.
      source: bocedwards-sds
      where: Section 8, Respiratory, Hand and Eye Protection
  mitigations: []
uses:
  - application: mechanisms
    device: Rotary and Roots mechanical vacuum pumps (sealing and lubricant fluid)
    example: SPI Supplies lists Fomblin Y LVAC Grade 25/6 for rotary pumps as a sealing and lubricant fluid, and for Roots pumps for lubrication.
    source: spi-25-6
    where: Product page, 'Choose Fomblin Y LVAC Grade 25/6 for' list
  - application: mechanisms
    device: Turbomolecular vacuum pumps
    example: SPI Supplies lists Fomblin Y LVAC Grade 06/6 for turbomolecular pumps. This is a reseller page, and it is not a manufacturer statement.
    source: spi-06-6
    where: Product page, use statement for Grade 06/6
  - application: electronics-and-chips
    device: Vacuum processing equipment in the electronic and electrical industries
    example: The Solvay 2014 SDS lists the electronic industry and the electrical industry as recommended uses, and states that the product is for industrial use only.
    source: solvay-sds-2014
    where: Section 1, Recommended use
supply:
  - subject: Perfluoropolyether (Fomblin Y), made by Solvay Specialty Polymers, a member of the Syensqo group
    abundance: Not found in any source read in this run. The product is a manufactured polymer, and no feedstock share or production figure was read.
    producers: []
    critical_lists: []
    recycling: Not found in any source read in this run.
    substitutes: []
    source: syensqo-tds-25-6
    where: Manufacturer named in the datasheet footer. Production countries, feedstock shares and critical-mineral status were not found in any source read.
  - subject: Fluorine, the element in the fluorinated chain, supplied through fluorspar (calcium fluoride) and hydrogen fluoride
    abundance: Not found in any source read in this run.
    producers:
      - country: China
        share_percent: 60
        year: 2025
      - country: Mexico
        share_percent: 15
        year: 2025
      - country: Mongolia
        share_percent: 15
        year: 2025
    critical_lists: []
    recycling: Not found in any source read in this run.
    substitutes: []
    source: usgs-mcs2026-fluorspar
    where: 'USGS Mineral Commodity Summaries 2026, Fluorspar: World Mine Production and Reserves table, 2025 column (thousand metric tons; shares calculated by Space Mushroom against the 10,000 t rounded world total). Feedstock: ''Aqueous HF is the primary feedstock for the manufacture of virtually all fluorine-bearing chemicals, particularly refrigerants and fluoropolymers'' (Domestic Production and Use). The link from that feedstock to this PFPE is not stated in the USGS text.'
documents:
  - title: Fomblin Y LVAC 25/6 Technical Data Sheet (Solvay Specialty Polymers, Syensqo group, revised 3/24/2020; copy hosted by Kurt J. Lesker Company)
    type: datasheet
    url: https://www.lesker.com/newweb/fluids/pdf/Fomblin_Y_MFY25-6-1KG_and_5KG.pdf
    year: 2020
  - title: 'Material Safety Data Sheet: Mechanical Pump Oil, Fomblin Y/LVAC Series (BOC Edwards, P120-01-015, Issue C)'
    type: sds
    url: https://uwaterloo.ca/giga-to-nanoelectronics-centre/sites/default/files/uploads/files/fomblinoil.pdf
  - title: 'Safety Data Sheet: FOMBLIN Y LVAC (Solvay, P 19889 / USA, issuing date 09/19/2014, report version 2.0)'
    type: sds
    url: https://cores.research.utdallas.edu/files/2023/04/fomblin-y-06-6-msds.pdf
    year: 2014
  - title: 'SPI Supplies product page: FOMBLIN Y LVAC Grade 25/6, item Z00073'
    type: datasheet
    url: https://www.2spi.com/item/z00073/
  - title: 'SPI Supplies product page: FOMBLIN Y LVAC Grade 06/6, item Z00078'
    type: datasheet
    url: https://www.2spi.com/item/z00078/
  - title: 'USGS Mineral Commodity Summaries 2026: Fluorspar'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
gaps:
  - 'Supply: no production country, production share or abundance for PFPE itself was found in any source read in this run. The supply entry uses USGS fluorspar 2026 world production as the fluorine feedstock. Fluorspar status on the USGS and EU critical-mineral lists was not read in this run, so critical_lists is empty.'
  - 'PFAS regulation: the EU PFAS restriction status for PFPE was not read from a fetched page. The industry article found by search returned HTTP 403, so no regulatory statement is recorded. Wikipedia describes perfluoropolyethers as a type of PFAS; that is not a regulatory finding and is not recorded as one.'
  - 'Vapour pressure: the Solvay 2014 SDS prints 0.0000001 - 0.000013 hPa at 20 °C for the product family, and the datasheet prints 6E-8 torr at 25 °C. Neither is a property row, because the value check cannot match the first form and the second is in exponent notation. The Edwards SDS gives grade values in exponent notation as well, so they are not recorded either.'
  - 'Eighth source: a web search for a second Fomblin Y safety data sheet could not be run because the search budget for this run was used up. The profile has seven sources; a further SDS or Syensqo product page would bring it to eight.'
  - 'Property names: boiling_point is in property-canon. kinematic_viscosity, viscosity_index, pour_point, surface_tension, heat_of_vaporization, evaporation_loss, decomposition_temperature, dynamic_viscosity and specific_gravity are not in property-canon and were used as short names.'
  - 'PubChem GHS record for CAS 69991-67-9 was not read: the page showed a browser check and did not load. The hazard section rests on the two SDS documents only.'
  - 'Outgassing: no total mass loss, collected volatile condensable material or other NASA outgassing result for the Fomblin Y LVAC grades was found.'
  - 'Radiation: the datasheet lists ''Good radiation stability'' as a feature only. No dose, test or flight result was found.'
  - 'Flight: no space flight result for Y LVAC was found. The fluid is used in vacuum pumps on the ground.'
  - Solvay's vacuum-applications brochure (solvay.com PDF) returned HTTP 404 in this run, so it was not read.
  - Viscosity and pour point for grades other than 25/6 were not found in a readable manufacturer source. The 06/6 property table on SPI page z00078 is headed 25/6 and its values were not used.
  - 'Vapour pressure: the values are not recorded as property rows because the exponent notation (6E-8, 2.0 x 10-9) could not be matched by the value check. The datasheet gives torr at 25 °C and 100 °C, while the Edwards SDS gives mbar at 20 °C, and the 2014 SDS gives a series range in hPa at 20 °C. The values were not converted or reconciled.'
  - 'Structure: the sources do not give the repeat units, end groups or the carbon, fluorine and oxygen ratio of the chain, so the recipe has no atom counts.'
  - 'Corrosion: no test of Y LVAC against metals, elastomers or plastics was found, beyond the datasheet feature statement. The elastomer and seal swelling data were not found.'
  - 'Ageing: the only ageing data is the 22 h evaporation loss at 149 °C in the datasheet. No long-term thermal or oxidation test was found.'
sources:
  syensqo-tds-25-6:
    title: Fomblin Y LVAC 25/6 perfluoropolyether technical data sheet (Solvay Specialty Polymers, a member of the Syensqo group), revised 3/24/2020, hosted by Kurt J. Lesker Company
    url: https://www.lesker.com/newweb/fluids/pdf/Fomblin_Y_MFY25-6-1KG_and_5KG.pdf
    year: 2020
    kind: datasheet
    license: Manufacturer technical data sheet, cited and not reproduced; the datasheet says the typical properties are not specifications
  bocedwards-sds:
    title: 'Material Safety Data Sheet: Mechanical Pump Oil - Fomblin Y/LVAC Series (06/6, 14/6, 16/6, 25/6, 25/9), BOC Edwards, P120-01-015 Issue C, rev. date 01-06-05'
    url: https://uwaterloo.ca/giga-to-nanoelectronics-centre/sites/default/files/uploads/files/fomblinoil.pdf
    kind: datasheet
    license: Supplier safety data sheet, cited and not reproduced
  solvay-sds-2014:
    title: 'Safety Data Sheet: FOMBLIN Y LVAC (Solvay, product P 19889 / USA, issuing date 09/19/2014, report version 2.0)'
    url: https://cores.research.utdallas.edu/files/2023/04/fomblin-y-06-6-msds.pdf
    year: 2014
    kind: datasheet
    license: Manufacturer safety data sheet, cited and not reproduced
  spi-25-6:
    title: 'SPI Supplies product page: FOMBLIN Y LVAC Grade 25/6 Perfluorinated Polyether Mechanical Pump Fluid (item Z00073)'
    url: https://www.2spi.com/item/z00073/
    kind: web
    license: Reseller product page, cited and not reproduced
  spi-06-6:
    title: 'SPI Supplies product page: FOMBLIN Y LVAC Grade 06/6 Perfluorinated Polyether Mechanical Pump Fluid (item Z00078)'
    url: https://www.2spi.com/item/z00078/
    kind: web
    license: Reseller product page, cited and not reproduced
  usgs-mcs2026-fluorspar:
    title: 'USGS Mineral Commodity Summaries 2026: Fluorspar (World Mine Production and Reserves table; Domestic Production and Use)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
    kind: report
    license: U.S. Government work, cited and not reproduced
  wikipedia-pfpe:
    title: 'Wikipedia: Perfluoropolyether (Manufacture section, PFPE-Y photooxidation of hexafluoropropylene)'
    url: https://en.wikipedia.org/wiki/Perfluoropolyether
    kind: web
    license: CC BY-SA 4.0, cited and not reproduced
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 13
  unreachable: 3
  caveats: 3
  note: 'Read by an AI assistant on 2026-11-01 from the datasheet and safety data sheets named above (PDFs extracted with pdftotext; the SPI pages read in the browser and by fetch). Unreachable: Solvay vacuum brochure (HTTP 404), PubChem (browser check), the EU PFAS industry article (HTTP 403). Caveats: the vapour pressure values use different units and temperatures and were not converted; the 2spi 06/6 property table is mislabelled 25/6 and was not used; the decomposition temperature is 290 °C (the Edwards sheet also prints 588 °F).'
story:
  recipe:
    line: Fomblin Y is a perfluorinated polyether, a mixture of fluorinated polymers made by a photochemical process that begins with hexafluoropropylene (SPI product page). Wikipedia's Manufacture section says photooxidation of hexafluoropropylene is applied to PFPE-Y. The 2014 SDS names it '1-Propene, 1,1,2,3,3,3-hexafluoro-, oxidized, polymd.' with CAS 69991-67-9 at more than 99.9 % (Solvay 2014 SDS). The chain contains only carbon, fluorine and oxygen (SPI page, quoting the manufacturer). The sources give no atom counts.
    parts:
      - name: Carbon
        symbol: C
        role: The backbone of the polymer chain, bonded to fluorine and oxygen.
      - name: Fluorine
        symbol: F
        role: Part of the perfluorinated chain. The SPI page lists chemical inertness and low surface tension among the properties of this chain family.
      - name: Oxygen
        symbol: O
        role: Links the carbon units into the polyether chain.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified
      lead: The 2014 Solvay safety data sheet does not classify the fluid under the US hazard communication standard, and the Edwards sheet describes it as not dangerous when handled properly.
      points:
        - label: The fluid
          line: The Solvay sheet gives an acute oral LD50 in rat of more than 15,000 mg/kg and an acute dermal LD50 of more than 5,000 mg/kg. It shows no skin or eye irritation in rabbits.
        - label: Vapour
          line: The Edwards sheet says vapours that may irritate the respiratory system can be released above 290 °C (554 °F).
    - title: If it overheats
      level: 2
      verdict: Toxic gas above 290 °C
      lead: These are the failure routes named in the safety data sheets. No rate or test result is given for any of them.
      points:
        - label: Above 290 °C
          line: The fluid may decompose above 290 °C, releasing hydrogen fluoride and carbonyl fluoride, which are toxic and corrosive (Edwards sheet). The Solvay 2014 sheet also names fluorophosgene.
        - label: Metals and Lewis acids
          line: Metals promote and lower the decomposition temperature. Lewis acids such as AlCl3, SbF5 and CoF3 should be avoided above 100 °C (Solvay 2014 sheet).
    - title: Handling and storage
      points:
        - label: Heat
          line: Avoid heating above 290 °C (554 °F) and keep the fluid away from heat and ignition sources.
        - label: Containers
          line: Store in glass or polyethylene containers. Take measures against the build-up of static electricity during transfer.
  why: Fomblin Y LVAC is a perfluorinated polyether, a liquid with a very low vapour pressure that is sold for mechanical vacuum pumps. The Syensqo datasheet lists low vapor pressure as a feature of the 25/6 grade. The manufacturer's chain is built only of carbon, fluorine and oxygen, which the SPI product page links to chemical inertness and high thermal stability.
  uses:
    - where: Rotary and Roots vacuum pumps
      line: A reseller lists Fomblin Y LVAC Grade 25/6 for rotary pumps, as a sealing and lubricant fluid, and for Roots pumps, for lubrication. The statement is from SPI Supplies, not from the manufacturer.
    - where: Turbomolecular pumps
      line: The same reseller lists Grade 06/6 for turbomolecular pumps.
    - where: Electronics and electrical industries
      line: The 2014 Solvay safety data sheet lists the electronic and electrical industries as recommended uses, for industrial use only.
  can_do:
    - label: Low vapour pressure
      line: The Syensqo datasheet lists low vapor pressure as a feature of the 25/6 grade and prints values at two temperatures. The five grades in the Edwards sheet differ in vapour pressure, and the grade sets how low it is.
    - label: Stays liquid when cold
      line: The 25/6 grade has a pour point of -35 °C (ASTM D97, Syensqo datasheet).
    - label: Viscosity
      line: The 25/6 grade has a kinematic viscosity of 276 cSt at 20 °C and a viscosity index of 113 (ASTM D445 and D2270, Syensqo datasheet).
    - label: Heat limit
      line: The fluid starts to decompose above 290 °C (Solvay 2014 sheet). Heat above that point should be avoided.
  compare: The Edwards sheet prints a vapour pressure at 20 °C for each of its five grades (06/6, 14/6, 16/6, 25/6 and 25/9), and the grades differ widely in volatility. The Syensqo datasheet prints 25/6 in torr at 25 °C and the Edwards sheet in mbar at 20 °C, so the two are not directly comparable and none is converted here. The vapour pressure values are not in the table because their exponent notation could not be matched to the printed text. The table compares density, evaporation loss and viscosity.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Evaporation weight loss
      benchmark: evaporation_loss
    - label: Kinematic viscosity
      benchmark: kinematic_viscosity
  handling:
    - Keep the fluid below 290 °C. Above that the SDS says it decomposes into hydrogen fluoride.
    - Keep it away from Lewis acids above 100 °C and from aluminium and magnesium powder above 200 °C.
    - Use self-contained breathing apparatus if the fluid is heated to decomposition.
  good_for:
    - 'Low volatility in a vacuum: the Syensqo datasheet lists low vapor pressure as a feature of grade 25/6, with a 0.6 wt% evaporation loss in 22 h at 149 °C.'
    - Pump sealing and lubrication in mechanical pumps, named by a reseller for rotary and Roots pumps.
  watch_out:
    - 'Heat and metals: decomposition starts above 290 °C, and metals lower that temperature (Solvay 2014 sheet).'
    - Decomposition releases hydrogen fluoride, which is toxic and corrosive (Edwards sheet).
    - 'Grade choice matters: the Edwards sheet prints very different vapour pressures at 20 °C for grades 06/6 and 25/9.'
    - No outgassing, radiation or space flight test result was found, so the fluid is not shown to be flight-qualified.
  verdict: Fomblin Y LVAC is a low-volatility perfluoropolyether pump fluid, and the grade sets how low. It is chemically inert below 290 °C, but it breaks down above that temperature into hydrogen fluoride, and metals and Lewis acids lower the limit. No space outgassing or flight result was found.