ASTM D848-23

Standard Test Method for Acid Wash Color of Industrial Aromatic Hydrocarbons

SIGNIFICANCE AND USE
5.1 This test method is suitable for setting specifications on the materials referenced in 1.1. It may also be used as an internal quality control tool and in development or research work.  
5.2 The color developed in the acid layer gives an indication of impurities which if sulfonated would cause the material to be discolored.
SCOPE
1.1 This test method covers the determination of the acid wash color of benzene, toluene, xylenes, refined solvent naphthas, and similar industrial aromatic hydrocarbons.  
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 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. For specific hazard statements, see Section 8 and 12.1.  
1.4 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: 31-Mar-2023
• ICS: 71.080.15 - Aromatic hydrocarbons
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.01 - Benzene, Toluene, Xylenes, Cyclohexane and Their Derivatives

Relations

• Refers: ASTM D6809-02(2016) - Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• Effective Date: 01-Nov-2016
• Refers: ASTM D4790-14 - Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
• Effective Date: 01-Jul-2014
• Refers: ASTM D4790-11 - Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
• Effective Date: 01-Feb-2011
• Refers: ASTM D3437-11 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jan-2011
• Refers: ASTM D3437-10 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jun-2010
• Refers: ASTM D3437-08 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jun-2008
• Refers: ASTM D4790-07 - Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
• Effective Date: 15-Jul-2007
• Refers: ASTM D6809-02(2007) - Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• Effective Date: 01-Jun-2007
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D4790-99(2004) - Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
• Effective Date: 01-Jun-2004
• Refers: ASTM D3437-03 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 10-Jun-2003
• Refers: ASTM D6809-02 - Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• Effective Date: 10-Jun-2002
• Refers: ASTM D4790-99 - Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
• Effective Date: 10-Jun-1999
• Refers: ASTM D3437-99 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 10-Jun-1999
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM D848-23: Standard Test Method for Acid Wash Color of Industrial Aromatic Hydrocarbons is a key international standard that outlines a procedure to determine the acid wash color of specific industrial aromatic hydrocarbons, including benzene, toluene, xylenes, and refined solvent naphthas. Developed by ASTM International, this standard provides a recognized method for evaluating the presence of certain impurities in these materials, primarily based on how the sample reacts with sulfuric acid.

The color developed in the acid layer during this test is an important quality indicator. This method is widely used to set material specifications, conduct internal quality control, and support research and development activities within the chemical and petroleum industries.

Key Topics

• Scope and Applicability: Covers the acid wash color determination of various industrial aromatic hydrocarbons, with results reported using SI units. The method is suitable for specification setting and as a quality control tool.
• Significance of Acid Wash Color: The test indicates impurities that, if sulfonated, would cause discoloration of the product, serving as a quick assessment of sample purity.
• Test Procedure Overview: Involves mixing an aromatic hydrocarbon sample with sulfuric acid, shaking vigorously, and comparing the resulting acid layer color to reference color standards.
• Quality and Precision: Supports ongoing laboratory quality assurance/quality control (QA/QC) practices and encourages interlaboratory comparisons for reliable results.
• Safety Practices: Emphasizes the importance of following relevant health, safety, and environmental guidelines due to the use of strong acids and volatile chemicals.

Applications

Acid wash color testing plays a crucial role in the following areas:

• Quality Assurance in Production: Used by manufacturers and quality control laboratories to verify that aromatic hydrocarbons meet required purity and color specifications before shipping or use in downstream processes.
• Material Certification: Essential for certifying that bulk chemicals comply with contract or regulatory requirements, such as those applicable to benzene, toluene, and xylenes.
• Process Control: Enables early detection of unacceptable levels of sulfonatable impurities, preventing costly reprocessing or contamination.
• Research and Development: Supports the development of improved refining processes and new product formulations by providing a quick and reliable impurity check.
• Interlaboratory Testing: Encourages cross-lab consistency and comparability when evaluating product quality, especially important in supplier-customer and regulatory contexts.

Related Standards

For comprehensive quality control and terminology within the field of aromatic hydrocarbons, the following ASTM standards are relevant:

• ASTM D1193: Specification for Reagent Water - outlines quality criteria for water used in testing.
• ASTM D3437: Practice for Sampling and Handling Liquid Cyclic Products - details proper methods for obtaining representative test samples.
• ASTM D4790: Terminology of Aromatic Hydrocarbons and Related Chemicals - provides standardized definitions.
• ASTM D6809: Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials - supports development of effective QA/QC strategies.

Summary

ASTM D848-23 provides a consistent, international procedure for determining the acid wash color of industrial aromatic hydrocarbons, an important indicator of chemical purity and suitability for use. Adherence to this test method supports reliable quality control, regulatory compliance, and enhanced consumer confidence in aromatic hydrocarbon products. For best results, laboratories should combine this method with related ASTM standards for sampling, terminology, and quality assurance.

Keywords: acid wash color, aromatic hydrocarbons, ASTM D848, benzene, toluene, xylene, quality control, chemical purity, industrial 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: D848 − 23
Standard Test Method for
Acid Wash Color of Industrial Aromatic Hydrocarbons
This standard is issued under the fixed designation D848; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 2.2 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and
1.1 This test method covers the determination of the acid
1910.1200
wash color of benzene, toluene, xylenes, refined solvent
naphthas, and similar industrial aromatic hydrocarbons.
3. Terminology
1.2 The values stated in SI units are to be regarded as
3.1 See Terminology D4790 for definitions of terms used in
standard. No other units of measurement are included in this
this test method.
standard.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
4.1 A mixture of the aromatic hydrocarbon and sulfuric acid
safety concerns, if any, associated with its use. It is the
is vigorously shaken and the color of the acid layer is compared
responsibility of the user of this standard to establish appro-
with that of color standards prepared from CoCl and FeCl .
priate safety, health, and environmental practices and deter-
2 3
mine the applicability of regulatory limitations prior to use.
5. Significance and Use
For specific hazard statements, see Section 8 and 12.1.
5.1 This test method is suitable for setting specifications on
1.4 This international standard was developed in accor-
the materials referenced in 1.1. It may also be used as an
dance with internationally recognized principles on standard-
internal quality control tool and in development or research
ization established in the Decision on Principles for the
work.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.2 The color developed in the acid layer gives an indication
Barriers to Trade (TBT) Committee.
of impurities which if sulfonated would cause the material to
be discolored.
2. Referenced Documents
6. Apparatus
2.1 ASTM Standards:
6.1 Containers for Color Standards—Clear and
D1193 Specification for Reagent Water
unblemished, clean, French square, flint-glass, flat-bottom,
D3437 Practice for Sampling and Handling Liquid Cyclic
glass-stoppered, 30 mL capacity bottles holding 31 mL to
Products
33 mL when filled to the neck. The bottles shall be labeled with
D4790 Terminology of Aromatic Hydrocarbons and Related
the reference number of the color standard they contain (see
Chemicals
11.2).
D6809 Guide for Quality Control and Quality Assurance
Procedures for Aromatic Hydrocarbons and Related Ma-
6.2 Test Containers—Containers exactly like those de-
terials
scribed in 6.1 except that each French square bottle shall be
marked by etching to show when the bottle contains the
volume of 7 mL and 28 mL, respectively. Colored crayons and
1 similar markers shall not be used for marking the bottles.
This test method is under the jurisdiction of ASTM Committee D16 on
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-
7. Reagents
bility of Subcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and
Their Derivatives.
7.1 Purity of Reagents—Reagent grade chemicals shall be
Current edition approved April 1, 2023. Published April 2023. Originally
used in all tests. Unless otherwise indicated, it is intended that
approved in 1945. Last previous edition approved in 2018 as D848 – 18. DOI:
10.1520/D0848-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from U.S. Government Printing Office Superintendent of Documents,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
*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
D848 − 23
all reagents shall conform to the specifications of the Commit- 11.1.3 Solution C—Mix 3 ⁄2 volumes of Solution A with
tee on Analytical Reagents of the American Chemical Society, 36 ⁄2 volumes of Solution B and dilute with 90 volumes of
where such specifications are available. Other grades may be water.
used provided it is first ascertained that the reagent is of 11.1.4 Solution D—Mix 3 ⁄2 volumes of Solution A with
sufficiently high purity to permit its use without lessening the 36 ⁄2 volumes of Solution B.
accuracy of the determination. 11.1.5 Solution E—Prepare an aqueous solution of K CrO
2 4
saturated at 21 °C.
7.2 Purity of Water—Unless otherwise indicated, references
11.1.6 Solution F—Prepare an aqueous solution of K Cr O
2 2 7
to water shall be understood to mean distilled water, Type I or
saturated at 21 °C and dilute with an equal volume of water.
II as described in Specification D1193.
11.2 Prepare reference color standard solutions having the
7.3 Cobalt Chloride (CoCl · 6H O).
2 2
following compositions and numbered as specified below. It is
7.4 Ferric Chloride (FeCl · 6H O).
3 2
not required to make each color standard. Only those reference
color standards that bracket the samples being evaluated must
7.5 Hydrochloric Acid (1 + 39)—Mix 25 mL of hydrochlo-
be utilized.
ric acid (31 weight % HCl) with 975 mL of water.
No. 0—Distilled water.
7.6 Potassium Chromate (K CrO ).
2 4
No. 1—1 volume of Solution C plus 1 volume of water.
No. 2—5 ⁄2 volumes of Solution C plus 2 volumes of water.
7.7 Potassium Dichromate (K Cr O ).
2 2 7
No. 3—Solution C.
7.8 Sulfuric Acid (96 6 0.5 weight % H SO ).
No. 4—1 volume of Solution D plus 1 volume of water.
2 4
No. 5—5 ⁄2 volumes of Solution D plus 2 volumes of water.
7.9 Sulfuric Acid (78 6 0.5 weight % H SO ).
2 4 No. 6—Solution D.
No. 7—5 volumes of Solution E plus 2 volumes of water.
8. Hazards
No. 8—Solution E.
No. 9—7 volumes of Solution E plus ⁄2 volume of Solution F.
8.1 Consult current OSHA regulations, supplier’s Safety
No. 10—6 ⁄2 volumes of Solution E plus 1 volume of Solution F.
Data Sheets, and local regulations for all materials used in this No. 11—5 ⁄2 volumes of Solution E plus 2 volumes of Solution F.
No. 12—1 volume of Solution E plus 1 volume of Solution F.
test method.
No. 13—2 volumes of Solution E plus 5 volumes of Solution F.
No. 14—Solution F.
8.2 When handling strong acids or acid cleaning solutions,
wear proper personnel protective equipment.
11.3 Rinse the No. 0 container (6.1) and its glass stopper
three times with water, fill with water, and stopper. Rinse the
9. Sampling
No. 1 container and its stopper three times with reference color
9.1 Sample the material in accordance with Practice D3437.
standard solution No. 1 (11.2), fill with this solution, and
stopper. In this way, prepare the set of containers of color
10. Cleaning of Containers
standards from 0 through 14 having the compositions shown
10.1 Clean new containers (Section 6) with a cleaning
for the corresponding color solution standards in 11.2. When
solution that will not impact the results, such as a chromic acid
filling the French square bottles, leave 6 mm of vapor space
substitute, rinse with tap water followed by distilled water, and
below the neck of the bottle. Seal each container with paraffin
dry in an oven set at a minimum of 105 °C for at least 1 h.
to prevent loss by evaporation or seepage.
Likewise, clean all other glassware used in this test method.
NOTE 2—It is recommended color standards be prepared annually from
fresh solutions.
11. Preparation of Reference Color Standards
NOTE 1—Purchase of solutions or reference color standards, or both, is
12. Procedure
allowed. The user of this standard assumes the responsibility of ensuring
any purchased solutions or standards are prepared with materials that meet
12.1 Fill a clean, dry test container to the 7 mL mark with
the requirements expressed in the Reagents se
...

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: D848 − 18 D848 − 23
Standard Test Method for
Acid Wash Color of Industrial Aromatic Hydrocarbons
This standard is issued under the fixed designation D848; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope Scope*
1.1 This test method covers the determination of the acid wash color of benzene, toluene, xylenes, refined solvent naphthas, and
similar industrial aromatic hydrocarbons.
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 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. For specific hazard statements, see SectionsSection 8 and 12.1.
1.4 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:
D1193 Specification for Reagent Water
D3437 Practice for Sampling and Handling Liquid Cyclic Products
D4790 Terminology of Aromatic Hydrocarbons and Related Chemicals
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
2.2 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200
3. Terminology
3.1 See Terminology D4790 for definitions of terms used in this test method.
4. Summary of Test Method
4.1 A mixture of the aromatic hydrocarbon and sulfuric acid is vigorously shaken and the color of the acid layer is compared with
that of color standards prepared from CoCl and FeCl .
2 3
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility of
Subcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and Their Derivatives.
Current edition approved June 1, 2018April 1, 2023. Published June 2018April 2023. Originally approved in 1945. Last previous edition approved in 20142018 as
D848 – 14.D848 – 18. DOI: 10.1520/D0848-18.10.1520/D0848-23.
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.
Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
www.access.gpo.gov.
*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
D848 − 23
5. Significance and Use
5.1 This test method is suitable for setting specifications on the materials referenced in 1.1. It may also be used as an internal
quality control tool and in development or research work.
5.2 The color developed in the acid layer gives an indication of impurities which if sulfonated would cause the material to be
discolored.
6. Apparatus
6.1 Containers for Color Standards—Clear and unblemished, clean, French square, flint-glass, flat-bottom, glass-stoppered,
30-mL30 mL capacity bottles holding 31 to 33 mL 31 mL to 33 mL when filled to the neck. The bottles shall be labeled with the
reference number of the color standard they contain (see 11.2).
6.2 Test Containers—Containers exactly like those described in 6.1 except that each French square bottle shall be marked by
etching to show when the bottle contains the volume of 7 and 28 mL, 7 mL and 28 mL, respectively. Colored crayons and similar
markers shall not be used for marking the bottles.
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean distilled water, Type I or II as
described in Specification D1193.
7.3 Cobalt Chloride (CoCl · 6H O).
2 2
7.4 Ferric Chloride (FeCl · 6H O).
3 2
7.5 Hydrochloric Acid (1 + 39)—Mix 25 mL of hydrochloric acid (31 weight % HCl) with 975 mL of water.
7.6 Potassium Chromate (K CrO ).
2 4
7.7 Potassium Dichromate (K Cr O ).
2 2 7
7.8 Sulfuric Acid (96 6 0.5 weight % H SO ).
2 4
7.9 Sulfuric Acid (78 6 0.5 weight % H SO ).
2 4
8. Hazards
8.1 Consult current OSHA regulations, supplier’s Safety Data Sheets, and local regulations for all materials used in this test
method.
8.2 When handling strong acids or acid cleaning solutions, wear proper personnel protective equipment.
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for
Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
D848 − 23
9. Sampling
9.1 Sample the material in accordance with Practice D3437.
10. Cleaning of Containers
10.1 Clean new containers (Section 6) with a cleaning solution that will not impact the results, such as a chromic acid substitute,
rinse with tap water followed by distilled water, and dry in an oven set at a minimum of 105°C105 °C for at least 1 h. 1 h. Likewise,
clean all other glassware used in this test method.
11. Preparation of Reference Color Standards
NOTE 1—Purchase of solutions or reference color standards, or both, is allowed. The user of this standard assumes the responsibility of ensuring any
purchased solutions or standards are prepared with materials that meet the requirements expressed in the Reagents section of this standard. Likewise, the
user of this standard assumes the responsibility of ensuring any purchased solutions or standards are prepared as expressed in this section.
11.1 Stock Solutions—Prepare the following basic reagent solutions for use in preparing the reference color standards:
11.1.1 Solution A—Dissolve 59.50 g 59.50 g of CoCl ·6H O in HCl (1 + 39) and make up to 1 L 1 L in a volumetric flask with
2 2
HCl (1 + 39).
11.1.2 Solution B—Dissolve 45.054 g of FeCl ·6H O in HCl (1 + 39) and make up to 1 L 1 L in a volumetric flask with HCl
3 2
(1 + 39).
1 1
11.1.3 Solution C—Mix 3 ⁄2 volumes of Solution A with 36 ⁄2 volumes of Solution B and dilute with 90 volumes of water.
1 1
11.1.4 Solution D—Mix 3 ⁄2 volumes of Solution A with 36 ⁄2 volumes of Solution B.
11.1.5 Solution E—Prepare an aqueous solution of K CrO saturated at 21°C.21 °C.
2 4
11.1.6 Solution F—Prepare an aqueous solution of K Cr O saturated at 21°C21 °C and dilute with an equal volume of water.
2 2 7
11.2 Prepare reference color standard solutions having the following compositions and numbered as specified below. It is not
required to make each color standard. Only those reference color standards that bracket the samples being evaluated must be
utilized.
No. 0—Distilled water.
No. 1—1 volume of Solution C plus 1 volume of water.
No. 2—5 ⁄2 volumes of Solution C plus 2 volumes of water.
No. 3—Solution C.
No. 4—1 volume of Solution D plus 1 volume of water.
No. 5—5 ⁄2 volumes of Solution D plus 2 volumes of water.
No. 6—Solution D.
No. 7—5 volumes of Solution E plus 2
...