Nomex meta-aramid fibre and fabric Nomex

Woven aramid fibre, poly(m-phenylene isophthalamide), meta-aramid

Nomex is a meta-aramid, poly(m-phenylene isophthalamide), sold by DuPont as fibre, paper and pressboard.

9 sources · Updated 2026-10-19 · CC BY 4.0

Evidence level

5 of 5

Flown or field-proven

Stay insulating at heat

220 °C continuous service

Hold electrical strength

18 kV/mm to 34 kV/mm

Survive in orbit

1.41e-24 cm3/atom

Recipe, share of the weight

  • C6H8N2 34.8 percent of the monomer charge by mass (computed from 108.14 and 203.02 g/mol, 1:1 molar ratio)m-Phenylenediamine
  • C8H4Cl2O2 65.2 percent of the monomer charge by mass (computed from 108.14 and 203.02 g/mol, 1:1 molar ratio)Isophthaloyl chloride
  • C 70.6%Carbon
  • H 4.2%Hydrogen
  • N 11.8%Nitrogen
  • O 13.4%Oxygen

Best for

Flame-resistant, high-temperature electrical and thermal insulation layers: continuous service to 220 °C and an LOI above 20.8 at 220 °C, as printed by DuPont

Weakest at

Atomic oxygen in low Earth orbit: an erosion yield of 1.41e-24 cm3/atom on MISSE 2 means surface loss in orbit. Strength also falls with UV exposure and with heat ageing: about 65 % of breaking strength is kept after 1000 h at 260 °C

Risk at a glance

  • People Low. Monomer hazards read; finished fibre low risk per DuPont
  • If it fails Moderate. Atomic oxygen erosion in low Earth orbit
  • Corrosion Moderate. Strength falls to about 55 % after 80 hours of xenon-arc exposure; colour changes first.

Quick facts: Nomex

Key properties of Nomex
PropertyValueBasis
Density0.96 to 1.37 g/cm³2 sourced values across conditions
Tensile strength340 to 2,960 MPa3 sourced values across conditions
Thermal conductivity0.14 W/(m·K)1 sourced value
Thermal expansion (CTE)18 ppm/K1 sourced value
Maximum service temperature204 °C1 sourced value

What is the density of Nomex meta-aramid fibre and fabric?

Nomex meta-aramid fibre and fabric has a density of 0.96 to 1.37 g/cm³. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the thermal conductivity of Nomex meta-aramid fibre and fabric?

Nomex meta-aramid fibre and fabric has a thermal conductivity of 0.14 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Nomex meta-aramid fibre and fabric?

Nomex meta-aramid fibre and fabric has a coefficient of thermal expansion of 18 ppm/K. The source and test conditions are listed in the properties table on this page.

What is the tensile strength of Nomex meta-aramid fibre and fabric?

Nomex meta-aramid fibre and fabric has a tensile strength of 340 to 2,960 MPa. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the maximum service temperature of Nomex meta-aramid fibre and fabric?

Nomex meta-aramid fibre and fabric has a maximum service temperature of 204 °C. The source and test conditions are listed in the properties table on this page.

What is Nomex meta-aramid fibre and fabric used for?

Uses recorded in the sources include Extravehicular Mobility Unit Thermal Micrometeoroid Garment and ACES pressure suit; Thermal blankets on the Space Shuttle Orbiter; Honeycomb core and laminate for aircraft construction.

Why it exists

Nomex is a meta-aramid, poly(m-phenylene isophthalamide). The DuPont page for the Nomex 400 series prints a continuous service temperature of 220 °C for at least 10 years and a radiation tolerance of 800 Mrad before its useful properties are essentially unaffected. DuPont developed it and it was adopted for race-car and firefighter clothing after fatal racing fires (Wikipedia).

Where it's used

Space suits and spacecraft

Nomex was used in the EMU thermal micrometeoroid garment and the ACES pressure suit, and as thermal blankets on the Space Shuttle Orbiter (Wikipedia).

Aircraft

Honeycomb Nomex paper saturated with phenolic resin is used extensively in aircraft construction, and military flight suits are made of over 92 percent Nomex (Wikipedia).

Electronics

Nomex paper is used in electrical laminates such as circuit boards and transformer cores (Wikipedia).

Fire and vehicle protection

Firefighters, racing drivers and military crews wear Nomex clothing (Wikipedia).

Recipe

Woven aramid fibre, poly(m-phenylene isophthalamide), meta-aramid; repeat unit C14H10N2O2

Nomex is produced by condensation of the monomers m-phenylenediamine and isophthaloyl chloride (Wikipedia, Production). Each condensation step releases hydrogen chloride: C6H8N2 + C8H4Cl2O2 gives the repeat unit C14H10N2O2 and 2 HCl (formulas from PubChem, balance computed). The repeat unit has a molar mass of 238.2452, as printed for PPPA in NASA TM-2008-215490 Table II. The polymer is spun into fibre from a solution containing dimethylacetamide, and residual DMAC remains in the fibre (DuPont guide). Sheet is calendered paper made in a similar fashion (Wikipedia).

What Nomex is made of
IngredientShare of the weightWhat it does
m-Phenylenediamine C6H8N2 34.8 percent of the monomer charge by mass (computed from 108.14 and 203.02 g/mol, 1:1 molar ratio) Diamine monomer; its two amine groups react with the acid chloride groups to build the amide links.
Isophthaloyl chloride C8H4Cl2O2 65.2 percent of the monomer charge by mass (computed from 108.14 and 203.02 g/mol, 1:1 molar ratio) Diacid chloride monomer; the chloride groups leave as HCl, one per amide bond.
Carbon C 70.6% About 71 % of the repeat unit by mass (computed from C14H10N2O2, standard atomic weights).
Hydrogen H 4.2% Aromatic and amide hydrogens of the repeat unit.
Nitrogen N 11.8% Amide nitrogens of the repeat unit.
Oxygen O 13.4% Carbonyl oxygens of the amide groups.

Weight shares are as printed in the sources.

What it can do

Stay insulating at heat

220 °C continuous service

measured

Useful properties are maintained for at least 10 years of continuous exposure at temperatures up to 220 °C, as printed by DuPont for the paper.

Hold electrical strength

18 kV/mm to 34 kV/mm

measured

Short-term dielectric strength of densified Nomex papers and pressboards is printed as 18 kV/mm to 34 kV/mm, depending on product and thickness.

Survive in orbit

1.41e-24 cm3/atom

measured

The MISSE 2 flight sample of PPPA (Nomex) has an erosion yield of 1.41e-24 cm3/atom, as listed in NASA TM-2008-215490.

How it compares

The DuPont values are for Nomex 400 series paper, and the erosion yield is for one flight sample, so the rows are examples and not a ranking. The Nomex 410 paper has a density of 0.96 g/cc and a machine-direction tensile strength of 296 N/cm at 10 mil, and its 220 °C limiting oxygen index is 22 to 25 %. The Type 450 fibre has a density of 1.37 g/cm3, a tenacity of 2.9 gm/den and an elongation of 22 %. Kevlar is stronger, since Nomex strands cannot align during polymerisation (Wikipedia).

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Compare every grade in the family.

Benchmarks
MeasurementNomex
Thermal behavior and safety
Thermal conductivity, Nomex 410 paper 0.25 mm, at 150 °C139 mWatt/meter K13
Weight loss onset in air or nitrogen, Nomex Type 455 fibre (TGA)400 °C19
Lifetime and stability
Dielectric strength retained at 95 % relative humidity, densified NomexValue printed on the DuPont characteristics page90 %4
Tensile strength retained after electron radiation, Nomex 410 paper MD65 % of original12
Breaking strength retained after heat ageing, Nomex fibre65 % of original20
Strength retained after xenon-arc UV exposure, 200 denier Type 430 yarn55 % of original21
Physical and electrical
Density, Nomex 410 paper, 0.25 mm (10.2 mil)0.96 g/cc5
Density, Nomex Type 450 staple fibre1.37 g/cm³14
Temperature behavior
Continuous service temperature, Nomex 400 seriesValue printed on the DuPont characteristics page220 °C
Other measurements
Atomic oxygen erosion yield, PPPA (Nomex), MISSE 21.41×10^-24 cm³/atom1
Short-term dielectric strength, densified Nomex 400 series18 kV/mm2
Limiting oxygen index at 220 °C, Nomex 400 series20.8 %3
Ionizing radiation before loss of useful properties, Nomex paperValue printed on the DuPont characteristics page800 Mrad
Tensile strength, machine direction, Nomex 410 paper 0.25 mm296 N/cm6
Tensile strength, cross direction, Nomex 410 paper 0.25 mm161 N/cm7
Elongation, machine direction, Nomex 410 paper 0.25 mm22 %8
Shrinkage at 300 °C, machine direction, Nomex 410 paper 0.25 mm0.4 %9
Limiting oxygen index at 220 °C, Nomex 410 paper22 %10
Limiting oxygen index at room temperature, Nomex 410 paper27 %11
Tenacity, Nomex Type 450 staple yarn2.9 gm/den15
Elongation at break, Nomex Type 450 staple yarn22 %16
Coefficient of linear expansion, Nomex fibre, 26 to 130 °C1.8×10^-5 cm/cm-°C17
Maximum continuous operating temperature, Nomex fibre (hot-gas filtration)204 °C18
Equilibrium moisture regain, NOMEX IIIA fabric5 %22
Ultimate tensile strength, Nomex meta-aramid (general figure)340 MPa23

Why choose it, and why not

Good for

  • Insulation layers at high temperature: continuous service to 220 °C for at least 10 years, per DuPont for the paper.
  • Radiation-exposed insulation: useful properties kept to 800 Mrad (8 MGy), per DuPont.
  • Flame-resistant crew clothing, thermal blankets and honeycomb structures, per Wikipedia and DuPont.

Watch out for

  • Atomic oxygen erodes the surface at 1.41e-24 cm3/atom on MISSE 2, so exterior use needs protection or a rate allowance. The NASA predictive tool under-predicted this value (Table VII).
  • Fibre service temperature is recommended at 204 °C for long hot-gas exposure, below the 220 °C paper figure, and about 65 % of strength is kept after 1000 h at 260 °C.
  • UV light and sunlight reduce strength: about 55 % is kept after 80 h of xenon arc on yarn, and colour changes first (DuPont).
  • Strong alkalis at high temperature degrade the fibre, and hot water shrinks it by about 1.3 % in one exposure (DuPont).
  • No outgassing, space UV or thermal-cycling result for Nomex was read in this run.

Nomex is a meta-aramid with a continuous service temperature of 220 °C for paper, an LOI of 22 to 25 % at 220 °C, and about 65 % strength retained after 1000 h at 260 °C. In low Earth orbit it erodes at 1.41e-24 cm3/atom on MISSE 2, above the predictive tool's 1.03e-24. Fibre values now include density 1.37 g/cm3, tenacity 2.9 gm/den and elongation 22 %. Monomer hazards are sourced from PubChem; the finished-fibre SDS, feedstock and outgassing data are still missing.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Atomic oxygen erosion yield, PPPA (Nomex), MISSE 2Measured on MISSE 2 flight samples and listed in NASA TM-2008-215490platform ISS, MISSE 2 PEACE tray 1, low Earth orbitexposure 2001-08-16 to 2005-07-30, AO fluence 8.43e21 atoms/cm2—
2Short-term dielectric strength, densified Nomex 400 seriesTypical range printed on the DuPont characteristics pageform densified Nomex 400 series paper and pressboard, depending on product type and thicknessstress short-term electrical stress—
3Limiting oxygen index at 220 °C, Nomex 400 seriesPrinted on the DuPont characteristics page; unit added from the LOI definition as a volume percenttemperature 220 °Cthreshold above 20.8 is the critical value for combustion in air—
4Dielectric strength retained at 95 % relative humidity, densified Nomex—humidity 95 % relative humiditybasis share of bone-dry dielectric strengthproduct densified papers and pressboards—
5Density, Nomex 410 paper, 0.25 mm (10.2 mil)Typical value per Arclin Nomex 410 datasheet, density row; the datasheet says values are typical and not specification limitsform Nomex 410 insulation paper, nominal 10 milstate standard conditions, 23 C and 50 % RH—
6Tensile strength, machine direction, Nomex 410 paper 0.25 mmTypical value per ASTM D-828, Arclin Nomex 410 datasheetform Nomex 410 paper, nominal 10 mildirection machine direction (MD)—
7Tensile strength, cross direction, Nomex 410 paper 0.25 mmTypical value per ASTM D-828, Arclin Nomex 410 datasheetform Nomex 410 paper, nominal 10 mildirection cross direction (XD)—
8Elongation, machine direction, Nomex 410 paper 0.25 mmTypical value per ASTM D-828, Arclin Nomex 410 datasheetform Nomex 410 paper, nominal 10 mildirection machine direction (MD)—
9Shrinkage at 300 °C, machine direction, Nomex 410 paper 0.25 mmValue printed on the DuPont Nomex 410 datasheet (copy on spacematdb.com); the 2026 Arclin sheet does not print this rowtemperature 300 °Cform Nomex 410 paper, nominal 10 mildirection machine direction (MD)—
10Limiting oxygen index at 220 °C, Nomex 410 paperPrinted on the DuPont Nomex 410 datasheet (copy on spacematdb.com), Figure 11 texttemperature 220 °Cthickness 0.05 to 0.76 mm, depending on thickness and density—
11Limiting oxygen index at room temperature, Nomex 410 paperPrinted on the DuPont Nomex 410 datasheet (copy on spacematdb.com), Figure 11 texttemperature room temperaturethickness depending on thickness and density—
12Tensile strength retained after electron radiation, Nomex 410 paper MDTable V of the DuPont Nomex 410 datasheet (copy on spacematdb.com); at 8 Mgy the MD value is 94 %dose 64 Mgy (6400 megarads) of 2 MeV electronsform Nomex 410 paper, 0.25 mm, machine direction—
13Thermal conductivity, Nomex 410 paper 0.25 mm, at 150 °CTable IV of the DuPont Nomex 410 datasheet, all data taken at 150 Ctemperature 150 °Cform Nomex 410 paper, nominal 10 mil—
14Density, Nomex Type 450 staple fibreValue printed in the DuPont Technical Guide for NOMEX Brand Fiber, Table II-1product Type 450 meta-aramid staple, 1.5 dpf, 32/2 CCstate as tested in the DuPont table—
15Tenacity, Nomex Type 450 staple yarnDuPont Technical Guide Table II-1 straight tenacity; tenacity is a grams-per-denier value, not a stress in MPaproduct Type 450 staple, 1.5 dpf, 32/2 CC spun yarntest straight test, footnote 1 of Table II-1—
16Elongation at break, Nomex Type 450 staple yarnDuPont Technical Guide Table II-1 straight test, elongation at breakproduct Type 450 staple, 1.5 dpf, 32/2 CC spun yarntest straight test, footnote 1 of Table II-1—
17Coefficient of linear expansion, Nomex fibre, 26 to 130 °CValue printed in the DuPont Technical Guide Table II-1 (in/in F value 1.0e-5)range 26 to 130 C (78 to 266 F)product Type 430, 450, 455, 462 and N301 fibres in the table—
18Maximum continuous operating temperature, Nomex fibre (hot-gas filtration)Recommendation printed in the DuPont Technical Guide, Section II heat effectsbasis exposures lasting months to years, fibre formnote 400 F printed in the guide; this is a DuPont recommendation, not a test result—
19Weight loss onset in air or nitrogen, Nomex Type 455 fibre (TGA)Thermogravimetric analysis, Figure 2.5 text in the DuPont Technical Guide; rapid weight loss is seen above about 427 Catmosphere air or nitrogencriterion less than 10 % fibre weight loss up to this temperature—
20Breaking strength retained after heat ageing, Nomex fibreDuPont Technical Guide, prolonged exposure to dry air at 500 F, stated as breaking strength and toughness about 65 % of the value before exposureexposure 1000 h in dry air at 260 C, then returned to room temperatureform fibre yarn—
21Strength retained after xenon-arc UV exposure, 200 denier Type 430 yarnFigure 2.14 of the DuPont Technical Guide; retention is about 70 % after 40 h; laboratory results do not correlate directly with garment lifeexposure 80 h xenon arc, AATCC Test Method 16Eform untwisted 200 denier Type 430 yarn—
22Equilibrium moisture regain, NOMEX IIIA fabricValue printed in the DuPont Technical Guide, Moisture regain sectioncondition 70 F (21 C), 65 % RH, equilibriumtest ASTM D-2654—
23Ultimate tensile strength, Nomex meta-aramid (general figure)Wikipedia Nomex Properties section states 340 MPa (49,000 psi); no test standard givenbasis general figure for Nomex, orientation and test not stated—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Ultraviolet light, xenon arc (laboratory, 200 denier Type 430 yarn) moderate Strength falls to about 55 % after 80 hours of xenon-arc exposure; colour changes first.1
Heat ageing in dry air, 260 C for 1000 h moderate About 65 % of breaking strength is kept after 1000 h at 260 C.2
Electron radiation, 2 MeV beta, up to 64 Mgy (Nomex 410 paper) low Machine-direction tensile strength falls to 65 % and elongation to 18 % at 64 Mgy.3
Atomic oxygen, low Earth orbit (MISSE 2 flight) moderate Measured erosion yield 1.41e-24 cm3/atom, above the predictive tool value of 1.03e-24.4
Boiling water and hot wash low Boiling water shrinks Type 430 fibre by about 1.3 %, and repeated exposure adds to this.5
Strong mineral acids and strong alkalis at elevated temperature moderate Acids and alkalis degrade the fibre; the effect rises with concentration, time and temperature.6
Common organic solvents (alcohols, ketones, acetone, toluene, xylene) low Slight softening and swelling, which is largely reversible when the solvent is removed.7
Corrosion details
#EnvironmentDetailsTest conditions
1 Ultraviolet light, xenon arc (laboratory, 200 denier Type 430 yarn) DuPont reports about 70 % of original strength after 40 h and about 55 % after 80 h. Discolouration (natural yarn to deep bronze) is not by itself a sign of fibre damage. Fabric of NOMEX III keeps about 70 % at 40 h and 50 % at 80 h, and its flame resistance is not affected. basis laboratory xenon arc per AATCC 16E; DuPont says it cannot be correlated with garment lifestorage DuPont advises dark storage and says window glass does not block the 360 nm band fully
2 Heat ageing in dry air, 260 C for 1000 h After 1000 h at 260 C and return to room temperature, DuPont says breaking strength and toughness of Nomex fibre are about 65 % of the unaged value. For hot-gas filtration, a maximum continuous operating temperature of 204 C is recommended for exposures lasting months to years. basis fibre yarn in dry air, prolonged exposure
3 Electron radiation, 2 MeV beta, up to 64 Mgy (Nomex 410 paper) Table V of the DuPont datasheet gives tensile MD at 94 % and elongation MD at 76 % after 8 Mgy. At 64 Mgy the tensile MD is 65 %, elongation MD 18 %, and dielectric strength 31 kV/mm against 34 kV/mm unexposed. dose 0 to 64 Mgy, 2 MeV electrons
4 Atomic oxygen, low Earth orbit (MISSE 2 flight) NASA TM-2008-215490 Table VII lists the predicted yield for PPPA (Nomex) at 1.03e-24 cm3/atom and the MISSE 2 measured yield at 1.41e-24 cm3/atom. The predictive tool under-predicted erosion for this polymer. fluence 8.43e21 atoms/cm2 (MISSE 2, 3.95 years)
5 Boiling water and hot wash DuPont reports immediate shrinkage of about 1.3 % in boiling water for Type 430, and a total of 3.8 % after 100 five-minute exposures. Type 450 staple has a printed maximum water shrinkage of 4.0 % at 100 C. basis boiling water, fibre
6 Strong mineral acids and strong alkalis at elevated temperature DuPont Table II-3 rates 10 % hydrochloric acid at 21 C for 1000 h as an appreciable loss of 41 to 80 % of breaking strength. The guide says NOMEX resists acid solutions better than nylon, shows excellent resistance to alkalis at room temperature, but is degraded by strong alkalis at high temperatures. basis table of specific concentration, temperature and time combinations, Type 430 filament yarn
7 Common organic solvents (alcohols, ketones, acetone, toluene, xylene) Arclin states that common industrial solvents have a slight softening and swelling effect on Nomex 410 paper, similar to water, and that these effects are mainly reversible. DuPont says NOMEX fibre is highly resistant to most hydrocarbons and organic solvents. basis solvent exposure at room temperature

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The DuPont page prints flame and heat properties for Nomex paper. The monomers carry GHS hazard codes, and the finished fibre has a low hazard profile according to DuPont.

Flame
The LOI at 220 °C is above 20.8, the critical value for combustion in air.
Monomers
PubChem lists m-phenylenediamine as toxic if swallowed, in contact with skin and if inhaled, and isophthaloyl chloride as causing severe skin burns and eye damage. Both are monomer hazards, not finished-product hazards.
Finished fibre
DuPont says finished Nomex presents no known adverse health or environmental effects and minimal risk, with combustion products similar to those of wood.

If it fails

The failure routes in these sources are erosion in orbit, heat ageing and UV.

Atomic oxygen
On MISSE 2 the PPPA (Nomex) erosion yield was 1.41e-24 cm3/atom, from NASA TM-2008-215490.
Heat and UV
About 65 % of breaking strength is kept after 1000 h at 260 °C, and about 55 % after 80 h in xenon-arc UV (DuPont).

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Atomic oxygen erosion in low Earth orbitmoderate severityExposure of an uncoated Nomex surface to atomic oxygen in low Earth orbit, as on the MISSE 2 flightSurface erosion at a yield of 1.41e-24 cm3/atom as measured on MISSE 2
Loss of strength from heat ageingmoderate severityLong exposure above the continuous service temperature, for example 1000 h at 260 CAbout 65 % of breaking strength is kept after 1000 h at 260 C (fibre), so margins must allow for the loss
Colour change and strength loss from UV lightmoderate severityProlonged sunlight or artificial UV exposure of unprotected garments or fabricNatural yarn turns from light tone to deep bronze; strength falls to about 55 % after 80 h in xenon arc (yarn)
Dimensional shrinkage in hot water or steamlow severityBoiling water or repeated hot wash, or steam with moisture and heatAbout 1.3 % shrinkage in one boiling exposure (Type 430), 3.8 % after 100 exposures

Side effects on surrounding parts

Side effects on surrounding parts
AffectsEffect
SurroundingsInfrequent skin irritation on first wearing of new garments, from stiff unwashed fabric at binding points and seams (DuPont).

Handling and storage

  • Keep garments and articles out of direct or indirect sunlight; store them in the dark. Incandescent light is preferable to fluorescent indoors, and storage near windows should be avoided (DuPont).
  • Wash a new garment at least once before wearing, to remove mill stiffeners (DuPont).

Mitigations

  • In dry-type electrical use, keep continuous stress on Nomex 410 paper at or below 1.6 kV/mm (40 V/mil) to limit partial discharge risk, per Arclin.

Supply and geography

How common the raw materials are and where they come from.

Nomex meta-aramid fibre and paper

Developed by DuPont in the early 1960s and first marketed in 1967 (Wikipedia). The Nomex 410 paper datasheet dated 04-2026 is issued under the Arclin name. No production volume or country share was read.

Top producers
DuPont, Arclin
Recycling
Not sourced.
Substitutes
Kevlar (para-aramid) has higher tensile strength. Nomex strands cannot align during filament polymerisation and have less strength, per Wikipedia. Kevlar is often added to Nomex to improve tear resistance.

Other meta-aramid and aramid paper producers

Named producers in Wikipedia. No share of world production is given.

Top producers
Teijin Aramid, Toray, Yantai Tayho, SRO Group, Kermel, Yantai Metastar Special Paper
Recycling
Not sourced.