Determination of Autogenous Ignition Temperature

of Isopropyl Alcohol and Ethanol

The NESC performed tests to measure the autogenous ignition temperature (AIT) of isopropyl alcohol (IPA) 

and ethanol in a pressurized, pure oxygen environment. The available data were for lower pressures than 

required and the majority of the data were for air rather than oxygen. Test results showed the average AITs 

for IPA in gaseous oxygen at 10.3 megapascals (MPa) (1,500 psi) and 15.2 MPa (2,200 psi) were 199.3 

degrees Celsius (°C) (390.8 degrees Fahrenheit (°F)) and 201.6°C (394.8°F), respectively. The average AITs 

for ethanol in gaseous oxygen at 10.3 MPa (1,500 psi) and 15.2 MPa (2,200 psi) were 193.2°C (379.8°F) 

and 198.2°C (388.8°F), respectively.

NASA Engineering and Safety Center Technical Bulletin No. 20-05

National Aeronautics and Space Administration

www.nasa.gov

Background

A request was recently made to NASA to provide the 

autogenous ignition temperature (AIT) of isopropyl alcohol (IPA) 

in a pressurized, pure oxygen environment. NASA provided the 

available data, but there was significant variability between 

data sources. The available data were for much lower 

pressures than required, and the majority of the data were for 

air rather than oxygen. The scatter seen in previous tests was 

likely due to test configuration and experimental technique 

differences, as well as inherent variability in the AIT response 

itself. NASA was requested to experimentally determine the 

AIT of both IPA and ethanol, both of which are extensively 

applied as cleaners and solvents in propulsion systems.

Test Procedures

The AIT testing of IPA and ethanol was performed at White 

Sands Test Facility (WSTF) for pressures representative of those 

found in spacecraft and launch vehicle propulsion systems. 

The WSTF standard test method was performed as follows. A 

sample holding assembly, contained within a reaction vessel 

pressurized with 100% oxygen to the required test pressure, 

was heated in an electric furnace at a rate of 5 ± 1°C (9 ± 

1°F)/min from 60 to 260°C (140 to 500°F). Heating of the 

vessel was continued at an uncontrolled rate to a maximum 

temperature of 450 °C (842°F). Temperatures were monitored 

as a function of time by means of a thermocouple and data 

acquisition system. During testing, pressure was monitored 

but not maintained. Ignition of the test sample was indicated 

by a rapid temperature rise of at least 20°C (36°F) and was 

confirmed post-test by the destruction of the sample.

The tests used Sigma-Aldrich anhydrous 2-propanol (IPA), 

part number 278475, 99.5% purity, and Sigma-Aldrich ethyl 

alcohol (ethanol), pure, part number 459844, minimum 99.5% 

purity, American Chemical Society reagent. Both the IPA and 

ethanol were used as received without further purification. 

Testing was performed for the IPA and the ethanol at both 10.3 

MPa (1,500 psi) and 15.2 MPa (2,200 psi). Five tests were run 

at each pressure using ~200 mg each of the IPA and ethanol. 

An additional test was run using 500 mg of IPA at 1,500 psi. 

Results

The results are tabulated in Tables 1 and 2.

References

1. Dorney, D.; Harper, S.; Reys, I.; Wentzel, D.; McClure, M.;

Juarez, A.: Determination of Autogenous Ignition Temperature

for Isopropyl Alcohol and Ethanol. NASA/TM-2020-5004683.

2. ASTM G72/G72M-15, Standard Test Method for Autogenous 

Ignition Temperatu re of Liquids and Solids in a High-Pressure 

Oxygen-Enriched Environment, ASTM International, West 

Conshohocken, Pennsylvania.

3. Wegener, W.; Binder, C.; Hengstenberg, P.; Herrmann, K.-P.;

and Weinert, D.’ “Tests to Evaluate the Suitability of Materials

for Oxygen Service,” Flammability and Sensitivity of Materials

in Oxygen-Enriched Atmospheres: Third Volume, ASTM STP

986, D. W. Schroll, Ed., ASTM, Philadelphia, 1988, pp. 268-278.

For information, contact Daniel J. Dorney at daniel.j.dorney@nasa.gov. 07/20/2020

www.nasa.gov Author: Daniel J. Dorney. For information, contact Jonathan Jones at jonathan.e.jones@nasa.gov 05/18/23