ASTM D8235-21

Standard Specification for Ethyl Tertiary-Butyl Ether (ETBE) for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel

SCOPE
1.1 This specification covers requirements for fuel grade ethyl tertiary-butyl ether (ETBE) utilized as a blend component at the 1 % to 22 % by volume for use as automotive spark-ignition engine fuel covered by Specifications D4814 and D8076 as well as other automotive fuel applications involving ETBE.  
1.1.1 Other ETBE grades may be available for blending that are not covered by this specification. Specification D7618 is also available from ASTM International.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 The following applies to all specified limits in this standard: For purposes of determining conformance with these specifications, an observed value or a calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the rounding method of Practice E29. All digits expressed in the specification limits are to be considered significant digits.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2021
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.A0.02 - Oxygenated Fuels and Components

Relations

• Refers: ASTM E203-24 - Standard Test Method for Water Using Volumetric Karl Fischer Titration
• Effective Date: 01-Jan-2024
• Refers: ASTM D4814-24 - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Jan-2024
• Refers: ASTM E1064-24 - Standard Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titration
• Effective Date: 01-Jan-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D4814-23a - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Dec-2023
• Refers: ASTM D156-23 - Standard Test Method for Saybolt Color of Petroleum Products (Saybolt Chromometer Method)
• Effective Date: 01-Oct-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D4814-20 - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Feb-2020
• Refers: ASTM D4814-19a - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Dec-2019
• Refers: ASTM D8076-19 - Standard Specification for 100 Research Octane Number Test Fuel for Automotive Spark-Ignition Engines
• Effective Date: 01-Dec-2019
• Refers: ASTM D4806-19a - Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
• Effective Date: 15-Sep-2019
• Refers: ASTM D5453-19a - Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
• Effective Date: 01-Jul-2019
• Refers: ASTM D7923-19 - Standard Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
• Effective Date: 01-Jun-2019
• Refers: ASTM D4806-19 - Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Mar-2019
• Refers: ASTM D4806-18a - Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Dec-2018

Overview

ASTM D8235-21 is the standard specification established by ASTM International for fuel-grade ethyl tertiary-butyl ether (ETBE) used as a blending component in automotive spark-ignition engine fuels. This specification outlines the essential requirements for ETBE when blended at proportions between 1% and 22% by volume with gasoline, as covered under ASTM D4814 and D8076. ETBE is an oxygenate commonly used to enhance fuel properties, such as antiknock characteristics and compliance with regulatory oxygen content mandates. The standard specifies quality, purity, sampling, and testing methods to ensure reliable performance and suitability for end-use applications.

Key Topics

• Scope and Limits: Specifies requirements for ETBE used as a fuel blending component, focusing on purity, contaminant levels, and approved blending ratios.
• Measurement Standards: All values are given in SI units, ensuring global consistency in quality assessment.
• Quality and Purity: ETBE must meet minimum purity requirements (typically 95% by mass), with strict limits on ethanol, C4-C6 hydrocarbons, methyl tertiary-butyl ether (MTBE), water, sulfur, and other impurities.
• Contaminant Control: The specification addresses the need to minimize contamination from silicon, chloride, sulfur, and water, all of which can adversely affect fuel performance and vehicle components.
• Sampling and Testing Protocols: Provides guidelines for the correct methods of sampling, sample handling, and testing-citing relevant ASTM methods for accuracy and repeatability.
• Workmanship: Includes visual inspection requirements, asserting that ETBE must be clear and bright, free of undissolved materials at the point of custody transfer.

Applications

• Automotive Fuels: ETBE is primarily used as an oxygenate additive in automotive gasoline for spark-ignition engines, helping to meet environmental regulations by improving combustion and reducing emissions.
• Fuel Quality Enhancement: ETBE contributes to a higher octane rating, supporting the production of high-performance and cleaner-burning fuels.
• Blending Flexibility: The specification allows for ETBE to be used in various grades of fuel blends, supporting utilities and refiners in achieving compliance with the Clean Air Act and similar regulations.
• Global Trade: By standardizing the quality parameters for ETBE, ASTM D8235-21 facilitates international trade and acceptance of ETBE-blended fuels, supporting harmonized fuel markets.

Related Standards

ASTM D8235-21 references and aligns with several other ASTM standards to ensure comprehensive quality control:

• ASTM D4814 - Specification for Automotive Spark-Ignition Engine Fuel
• ASTM D8076 - Specification for 100 Research Octane Number Test Fuel for Automotive Spark-Ignition Engines
• ASTM D7796 - Test Method for Analysis of Ethyl tert-Butyl Ether (ETBE) by Gas Chromatography
• ASTM D6304, D7923, E203, E1064 - Test Methods for Water Content
• ASTM D2622, D3120, D5453, D7039 - Test Methods for Sulfur Content
• ASTM D130 - Test Method for Copper Strip Corrosion
• ASTM D381 - Test Method for Gum Content in Fuels
• ASTM D4057, D4177 - Practices for Sampling Petroleum Products
• ASTM D7618 - Specification for ETBE for Aviation Spark-Ignition Engine Fuel
• ASTM D5983 - Specification for MTBE for Blending with Gasolines

Adhering to ASTM D8235-21 ensures that ETBE used in fuel blending meets consistent, internationally recognized standards for safety, performance, and quality, supporting both regulatory compliance and market acceptance.

Keywords: ETBE, ethyl tertiary-butyl ether, ASTM D8235-21, automotive gasoline, fuel blending, oxygenate, spark-ignition engine fuel, fuel specification, fuel quality, ASTM standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D8235 −21
Standard Specification for
Ethyl Tertiary-Butyl Ether (ETBE) for Blending with
Gasolines for Use as Automotive Spark-Ignition Engine
Fuel
This standard is issued under the fixed designation D8235; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
1.1 This specification covers requirements for fuel grade 2.1 ASTM Standards:
ethyltertiary-butylether(ETBE)utilizedasablendcomponent D130 Test Method for Corrosiveness to Copper from Petro-
at the1%to22%by volume for use as automotive leum Products by Copper Strip Test
spark-ignition engine fuel covered by Specifications D4814
D156 Test Method for Saybolt Color of Petroleum Products
and D8076 as well as other automotive fuel applications
(Saybolt Chromometer Method)
involving ETBE.
D381 Test Method for Gum Content in Fuels by Jet Evapo-
ration
1.1.1 Other ETBE grades may be available for blending that
D2622 Test Method for Sulfur in Petroleum Products by
are not covered by this specification. Specification D7618 is
Wavelength Dispersive X-ray Fluorescence Spectrometry
also available from ASTM International.
D3120 Test Method for Trace Quantities of Sulfur in Light
1.2 The values stated in SI units are to be regarded as
Liquid Petroleum Hydrocarbons by Oxidative Microcou-
standard. No other units of measurement are included in this
lometry
standard.
D4057 Practice for Manual Sampling of Petroleum and
1.3 The following applies to all specified limits in this Petroleum Products
standard: For purposes of determining conformance with these D4175 Terminology Relating to Petroleum Products, Liquid
Fuels, and Lubricants
specifications, an observed value or a calculated value shall be
D4177 Practice for Automatic Sampling of Petroleum and
rounded “to the nearest unit” in the last right-hand digit used in
expressing the specification limit, in accordance with the Petroleum Products
rounding method of Practice E29. All digits expressed in the D4306 Practice for Aviation Fuel Sample Containers for
specification limits are to be considered significant digits. Tests Affected by Trace Contamination
D4806 Specification for Denatured Fuel Ethanol for Blend-
1.4 This standard does not purport to address all of the
ing with Gasolines for Use as Automotive Spark-Ignition
safety concerns, if any, associated with its use. It is the
Engine Fuel
responsibility of the user of this standard to establish appro-
D4814 Specification for Automotive Spark-Ignition Engine
priate safety, health, and environmental practices and deter-
Fuel
mine the applicability of regulatory limitations prior to use.
D5453 Test Method for Determination of Total Sulfur in
1.5 This international standard was developed in accor-
Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel
dance with internationally recognized principles on standard-
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
ization established in the Decision on Principles for the
D5854 Practice for Mixing and Handling of Liquid Samples
Development of International Standards, Guides and Recom-
of Petroleum and Petroleum Products
mendations issued by the World Trade Organization Technical
D5983 Specification for Methyl Tertiary-Butyl Ether
Barriers to Trade (TBT) Committee.
(MTBE) for Blending With Gasolines for Use as Auto-
motive Spark-Ignition Engine Fuel
This specification is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.A0.02 on Oxygenated Fuels and Components. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2021. Published July 2021. Originally approved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 2018. Last previous edition approved in 2019 as D8235 – 19. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D8235-21. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8235−21
D6304 Test Method for Determination of Water in Petro- 3.3 Abbreviations:
leum Products, Lubricating Oils, and Additives by Cou- 3.3.1 C4—a molecule containing 4 carbon atoms.
lometric Karl Fischer Titration
3.3.2 C6—a molecule containing 6 carbon atoms.
D7039 Test Method for Sulfur in Gasoline, Diesel Fuel, Jet
4. Performance Requirements
Fuel, Kerosine, Biodiesel, Biodiesel Blends, and
Gasoline-Ethanol Blends by Monochromatic Wavelength
4.1 ETBE used in fuels for ground vehicles equipped with
Dispersive X-ray Fluorescence Spectrometry
spark-ignition engines shall conform to the requirements of
D7618 Specification for Ethyl Tertiary-Butyl Ether (ETBE)
Table 1.
for Blending with Aviation Spark-Ignition Engine Fuel
4.2 Other Properties—Limits more restrictive than those
D7757 Test Method for Silicon in Gasoline and Related
specified in Table 1, or the specification of additional proper-
Products by Monochromatic Wavelength Dispersive
ties may be agreed upon between the supplier and the pur-
X-ray Fluorescence Spectrometry
chaser.
D7796 Test Method for Analysis of Ethyl tert-Butyl Ether
(ETBE) by Gas Chromatography
5. Workmanship
D7923 Test Method for Water in Ethanol and Hydrocarbon
5.1 At the point of custody transfer, the ETBE shall be
Blends by Karl Fischer Titration
visually free of undissolved water, sediment, suspended or
D8076 Specification for 100 Research Octane Number Test
undissolved matter. It shall be clear and bright at the fuel
Fuel for Automotive Spark-Ignition Engines
temperature at the point of custody transfer or at a lower
E29 Practice for Using Significant Digits in Test Data to
temperature agreed upon by the purchaser and seller.
Determine Conformance with Specifications
5.1.1 Ethers, such as ETBE, are visually clear and bright
E203 Test Method for Water Using Volumetric Karl Fischer
under normal conditions when free of contamination. If the
Titration
product is not clear and bright, contamination of the product
E300 Practice for Sampling Industrial Chemicals
may have occurred.
E1064 Test Method for Water in Organic Liquids by Coulo-
5.2 The specification defines only a basic purity for this
metric Karl Fischer Titration
product. The product shall be free of any adulterant or
2.2 Government Regulations:
contaminant that can render the material unacceptable for its
CFR 40 Code of Federal Regulations
commonly used applications.
3. Terminology
5.2.1 If the product appears discolored prior to the addition
of any colored additives, contamination of the product may
3.1 For general terminology, refer to Terminology D4175.
haveoccurredandtestingforcontaminationmaybewarranted.
NOTE 1—The user is advised that the definitions used by various
Test Method D156 may be helpful in assessing the degree of
industries, marketers, and regulatory bodies can differ from those used in
color of the product.
thisspecification.Itistheresponsibilityoftheusertoensurethattheterms
used in a particular context are clearly understood.
5.3 Manufacturers and importers of ETBE shall avoid
contamination by silicon-containing materials. Silicon con-
3.2 Definitions:
tamination of gasoline-oxygenate blends has led to fouled
3.2.1 ethanol, n—ethyl alcohol, the chemical compound
vehicle components (for example, spark plugs, exhaust oxygen
CH CH OH. D4806
3 2
sensors, catalytic converters) requiring parts replacement and
3.2.2 ethyl tertiary-butyl ether (ETBE), n—the chemical
repairs. Test Method D7757 is a procedure for determining
compound CH CH OC(CH )
3 2 3 3
silicon that might be applicable to ETBE. Additional studies
3.2.2.1 Discussion—ETBE is also known as 2-ethoxy-2-
will be needed to include ETBE into the scope of Test Method
methylpropane.
D7757. No specification limits have been established for
3.2.3 finished fuel, n—a homogeneous mixture of blend-
silicon.
stocks and fuel additives meeting all specification and regula-
tory requirements for its intended use at the location where
TABLE 1 Performance Requirements
sold. D4814
Property Limit ASTM Test Method
3.2.4 methyl tertiary-butyl ether (MTBE), n—the chemical
ETBE, % by mass, min 95.0 D7796
compound CH OC(CH ) . D5983 Ethanol, % by mass, max 2.5 D7796
3 3 3
C4-C6 Hydrocarbons, % by mass, max 1.5 D7796
MTBE, % by mass, max 2.0 D7796
3.2.4.1 Discussion—MTBE is also known as 2-methoxy-2-
Water, % by mass, max 0.10 D6304, D7923, E203,
methylpropane.
E1064
A
3.2.5 oxygenate, n—a molecule composed solely of carbon,
Sulfur, mg/kg, max 30 D2622, D3120,
D5453, D7039
hydrogen, and oxygen. D4814
Copper Strip Corrosion, max 1 D130
3.2.5.1 Discussion—In this standard, the oxygenate of inter-
B
Solvent washed gum content, mg/ 5 D381
est is ETBE.
100 mL, max
A
Individual jurisdictions may require a more restrictive sulfur limit. These require-
ments are to be negotiated between buyer and seller.
B
Available from U.S. Government Printing Office, Superintendent of
The limit is included to ensure that finished fuels do not contain excess
Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
solvent-washed gum.
www.access.gpo.gov.
D8235−21
5.4 Manufacturers and importers of ETBE shall avoid 6.5 Lot Size—A lot shall normally consist of the amount
contamination by chloride-containing materials such as salt contained in a
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D8235 − 19 D8235 − 21
Standard Specification for
Ethyl Tertiary-Butyl Ether (ETBE) for Blending with
Gasolines for Use as Automotive Spark-Ignition Engine
Fuel
This standard is issued under the fixed designation D8235; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification covers requirements for fuel grade ethyl tertiary-butyl ether (ETBE) utilized as a blend component at the
1 % to 22 % by volume for use as automotive spark-ignition engine fuel covered by Specifications D4814 and D8076 as well as
other automotive fuel applications involving ETBE.
1.1.1 Other ETBE grades may be available for blending that are not covered by this specification. Specification D7618 is also
available from ASTM International.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 The following applies to all specified limits in this standard: For purposes of determining conformance with these
specifications, an observed value or a calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in
expressing the specification limit, in accordance with the rounding method of Practice E29. All digits expressed in the specification
limits are to be considered significant digits.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D130 Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
D156 Test Method for Saybolt Color of Petroleum Products (Saybolt Chromometer Method)
D381 Test Method for Gum Content in Fuels by Jet Evaporation
D2622 Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry
D3120 Test Method for Trace Quantities of Sulfur in Light Liquid Petroleum Hydrocarbons by Oxidative Microcoulometry
This specification is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.A0.02 on Oxygenated Fuels and Components.
Current edition approved July 1, 2019July 1, 2021. Published July 2019July 2021. Originally approved in 2018. Last previous edition approved in 20182019 as
D8235 – 18.D8235 – 19. DOI: 10.1520/D8235-19.10.1520/D8235-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8235 − 21
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
D4806 Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
D4814 Specification for Automotive Spark-Ignition Engine Fuel
D5453 Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel,
and Engine Oil by Ultraviolet Fluorescence
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
D5983 Specification for Methyl Tertiary-Butyl Ether (MTBE) for Blending With Gasolines for Use as Automotive Spark-
Ignition Engine Fuel
D6304 Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl
Fischer Titration
D7039 Test Method for Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol
Blends by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
D7618 Specification for Ethyl Tertiary-Butyl Ether (ETBE) for Blending with Aviation Spark-Ignition Engine Fuel
D7757 Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence
Spectrometry
D7796 Test Method for Analysis of Ethyl tert-Butyl Ether (ETBE) by Gas Chromatography
D7923 Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
D8076 Specification for 100 Research Octane Number Test Fuel for Automotive Spark-Ignition Engines
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E203 Test Method for Water Using Volumetric Karl Fischer Titration
E300 Practice for Sampling Industrial Chemicals
E1064 Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titration
2.2 Government Regulations:
CFR 40 Code of Federal Regulations
3. Terminology
3.1 For general terminology, refer to Terminology D4175.
NOTE 1—The user is advised that the definitions used by various industries, marketers, and regulatory bodies can differ from those used in this
specification. It is the responsibility of the user to ensure that the terms used in a particular context are clearly understood.
3.2 Definitions:
3.2.1 ethanol, n—ethyl alcohol, the chemical compound CH CH OH. D4806
3 2
3.2.2 ethyl tertiary-butyl ether (ETBE), n—the chemical compound CH CH OC(CH )
3 2 3 3
3.2.2.1 Discussion—
ETBE is also known as 2-ethoxy-2-methylpropane.
3.2.3 finished fuel, n—a homogeneous mixture of blendstocks and fuel additives meeting all specification and regulatory
requirements for its intended use at the location where sold. D4814
3.2.4 methyl tertiary-butyl ether (MTBE), n—the chemical compound CH OC(CH ) . D5983
3 3 3
3.2.4.1 Discussion—
MTBE is also known as 2-methoxy-2-methylpropane.
3.2.5 oxygenate, n—an oxygen-containing ashless, organic compound, such as an alcohol or ether, which may be used as a fuel
or fuel supplement.a molecule composed solely of carbon, hydrogen, and oxygen. D4814
3.2.5.1 Discussion—
In this standard, the oxygenate of interest is ETBE.
3.3 Abbreviations:
Available from U.S. Government Printing Office, Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://www.access.gpo.gov.
D8235 − 21
3.3.1 C4—a molecule containing 4 carbon atoms.
3.3.2 C6—a molecule containing 6 carbon atoms.
4. Performance Requirements
4.1 ETBE used in fuels for ground vehicles equipped with spark-ignition engines shall conform to the requirements of Table 1.
4.2 Other Properties—Limits more restrictive than those specified in Table 1, or the specification of additional properties may be
agreed upon between the supplier and the purchaser.
5. Workmanship
5.1 At the point of custody transfer, the ETBE shall be visually free of undissolved water, sediment, suspended or undissolved
matter. It shall be clear and bright at the fuel temperature at the point of custody transfer or at a lower temperature agreed upon
by the purchaser and seller.
5.1.1 Ethers, such as ETBE, are visually clear and bright under normal conditions when free of contamination. If the product is
not clear and bright, contamination of the product may have occurred.
5.2 The specification defines only a basic purity for this product. The product shall be free of any adulterant or contaminant that
can render the material unacceptable for its commonly used applications.
5.2.1 If the product appears discolored prior to the addition of any colored additives, contamination of the product may have
occurred and testing for contamination may be warranted. Test Method D156 may be helpful in assessing the degree of color of
the product.
5.3 Manufacturers and importers of ETBE shall avoid contamination by silicon-containing materials. Silicon contamination of
gasoline-oxygenate blends has led to fouled vehicle components (for example, spark plugs, exhaust oxygen sensors, catalytic
converters) requiring parts replacement and repairs. Test Method D7757 is a procedure for determining silicon that might be
applicable to ETBE. Additional studies will be needed to include ETBE into the scope of Test Method D7757. No specification
limits have been established for silicon.
5.4 Manufacturers and importers of ETBE shall avoid contamination by chloride-containing materials such as salt water or
halogenated hydrocarbons. Low concentrations of chloride ions are corrosive to many metals.
5.5 Manufacturers and importers of ETBE shall avoid contamination by sulfur-containing materials that can cause an increase in
the fuel sulfur content.
TABLE 1 Performance Requirements
Property Limit ASTM Test Method
ETBE, % by mass, min 95.0 D7796
Ethanol, % by mass, max 2.5 D7796
C4-C6 Hydrocarbons, % by mass, max 1.5 D7796
MTBE, % by mass, max 2.0 D7796
Water, % by mass, max 0.10 D6304, D7923, E203,
E1064
A
Sulfur, mg/kg, max 30 D2622, D3120,
D5453, D7039
Copper Strip Corrosion, max 1 D130
B
Solvent washed gum content, mg/100 ml, 5 D381
max
B
Solvent washed gum content, mg/ 5 D381
100 mL, max
A
Individual jurisdictio
...