ASTM D2108-10(2020)

Standard Test Method for Color of Halogenated Organic Solvents and Their Admixtures (Platinum-Cobalt Scale)

SIGNIFICANCE AND USE
2.1 Color may be indicative of the quality of the solvent because any color present is due to the presence of contaminants.
SCOPE
1.1 This test method covers the visual measurement of the color of halogenated organic solvents and their admixtures. It is valid for values of 50 platinum-cobalt (Pt-Co) units or less.  
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.  
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-Dec-2019
• ICS: 87.060.30 - Solvents
• Technical Committee: D26 - Halogenated Organic Solvents and Fire Extinguishing Agents
• Drafting Committee: D26.04 - Test Methods

Relations

• Replaces: ASTM D2108-10(2015) - Standard Test Method for Color of Halogenated Organic Solvents and Their Admixtures (Platinum-Cobalt Scale)
• Effective Date: 01-Jan-2020
• Referred By: ASTM D4376-15(2020) - Standard Specification for Vapor-Degreasing Grade Perchloroethylene
• Effective Date: 01-Jan-2020
• Referred By: ASTM D4080-15(2020) - Standard Specification for Trichloroethylene, Technical and Vapor-Degreasing Grade
• Effective Date: 01-Jan-2020
• Referred By: ASTM D7673/D7673M-21 - Standard Specification for Halon 1211, Bromochlorodifluoromethane (CF<inf>2</inf>BrCl)
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5616-04(2022) - Standard Specification for Reclaimed Trichloroethylene
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5395-03(2023) - Standard Specification for Reclaimed Methylene Chloride
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5960-03(2023) - Standard Specification for Technical Grade Ethylene Dichloride
• Effective Date: 01-Jan-2020
• Referred By: ASTM D4079-00(2022) - Standard Specification for Vapor-Degreasing Grade Methylene Chloride
• Effective Date: 01-Jan-2020
• Referred By: ASTM D6368-06(2023) - Standard Specification for Vapor-Degreasing Solvents Based on <emph type="bdit">normal</emph >-Propyl Bromide and Technical Grade <emph type="bdit">normal</emph >-Propyl Bromide
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5396-04(2020) - Standard Specification for Reclaimed Perchloroethylene
• Effective Date: 01-Jan-2020
• Referred By: ASTM D4701-00(2020) - Standard Specification for Technical Grade Methylene Chloride
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5386-16 - Standard Test Method for Color of Liquids Using Tristimulus Colorimetry
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5248-04(2020) - Standard Specification for Reclaimed 1,1,2-Trichloro 1,2,2-Trifluoroethane
• Effective Date: 01-Jan-2020
• Referred By: ASTM D5632/D5632M-17(2022) - Standard Specification for Halon 1301, Bromotrifluoromethane (CF<inf>3</inf>Br)
• Effective Date: 01-Jan-2020
• Referred By: ASTM D7509-09(2021) - Standard Specification for Fluorocarbon Feedstock Grade Chloroform
• Effective Date: 01-Jan-2020

Overview

ASTM D2108-10(2020) is an international standard developed by ASTM International for the visual measurement of the color of halogenated organic solvents and their admixtures, using the Platinum-Cobalt (Pt-Co) color scale. The color of these solvents serves as a crucial indicator of purity and can reveal the presence of contaminants. This standard establishes a clear, reproducible method for determining color, supporting consistency and quality control in laboratory and industrial settings for values up to 50 Pt-Co units.

Key Topics

• Visual Color Measurement: The method centers on visually comparing solvent samples to standardized color solutions in matched Nessler tubes, confirming if the sample color indicates suitable quality.
• Platinum-Cobalt Scale: The Pt-Co color scale is the internationally recognized system for quantifying color in clear, yellow-tinted liquids, providing standardized results.
• Equipment Recommendations:
  • Use of matched 50 mL or 100 mL Nessler tubes for accurate comparison.
  • Utilization of color comparators or digital color instruments calibrated according to standard color references.
• Reporting Standards:
  • Color should be reported as the nearest matching standard.
  • If there is no definite match due to differences in hue, report the apparent range and note as "off-hue."
• Precision: The test method specifies strong intralaboratory reproducibility, typically within 2 Pt-Co units.
• Quality of Reagents: Use reagent-grade chemicals and distilled water to ensure accuracy in the preparation of color standards and sample testing.

Applications

ASTM D2108 is widely adopted across chemical, manufacturing, and laboratory sectors for:

• Quality Assurance: Ensuring that halogenated organic solvents meet required purity and quality specifications by detecting colorants or contaminants.
• Product Development: Supporting research labs and industrial manufacturers in maintaining batch-to-batch consistency.
• Regulatory Compliance: Meeting product quality requirements set by organizations that reference ASTM protocols.
• Industrial Processes: Applicable to industries dealing with cleaning agents, refrigerants, and fire extinguishing agents, where solvent purity is essential.

By adhering to this standard, organizations can systematically evaluate the color and, by extension, the quality of organic solvents, facilitating comparability of results across different laboratories and production sites.

Related Standards

• ASTM D1209 - Standard Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)
• ASTM D511 - Standards for Water Quality Indicators
• ISO 2211 - International standard for determination of color in liquids using the platinum-cobalt scale
• American Chemical Society Specifications - Guidelines for reagent quality and preparation

For optimal results, users should cross-reference related ASTM and ISO standards to ensure comprehensive quality control procedures for chemical substances.

Practical Value

Adopting ASTM D2108-10(2020) in laboratory and industrial practices ensures:

• Consistent quality control for halogenated organic solvents and admixtures
• Reliable detection of color deviations that may signal contamination or degradation
• Streamlined communication between labs, manufacturers, and regulatory agencies by using an internationally accepted standard
• Support for traceability and transparency in product documentation and reporting

By implementing this test method, professionals involved in chemical analysis, quality assurance, and regulatory compliance benefit from reliable, standardized color measurement practices aligned with global best practices.

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: D2108 − 10 (Reapproved 2020)
Standard Test Method for
Color of Halogenated Organic Solvents and Their
Admixtures (Platinum-Cobalt Scale)
This standard is issued under the fixed designation D2108; 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 3.3 Digital Color Instrument—Digital color instruments are
available that measure color digitally and convert the result to
1.1 This test method covers the visual measurement of the
a numerical value using the Platinum-Cobalt scale. Many
color of halogenated organic solvents and their admixtures. It
manufacturers market instruments of this type.
is valid for values of 50 platinum-cobalt (Pt-Co) units or less.
NOTE 1—There are numerous colorimeters and comparators commer-
1.2 The values stated in SI units are to be regarded as cially available that measure the color of liquids and take some of the
subjectivity out of the measurement. These instruments may be calibrated
standard. No other units of measurement are included in this
with the platinum-cobalt color standards listed in Table 1 at 455 mm or
standard.
withopticallystandardizedcolorfilterdiskssuchasthoseavailableforthe
1.3 This standard does not purport to address all of the
Hellige Aqua Tester. Many of these instruments take the measurement
across a relatively narrow range of wave lengths, and their readings may
safety concerns, if any, associated with its use. It is the
be in error if the color of the sample is significantly different from the
responsibility of the user of this standard to establish appro-
amber color of the color standards.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Reagents
1.4 This international standard was developed in accor-
4.1 Purity of Reagents—Reagent grade chemicals shall be
dance with internationally recognized principles on standard-
used in all tests. Unless otherwise indicated, it is intended that
ization established in the Decision on Principles for the
all reagents shall conform to the specifications of the Commit-
Development of International Standards, Guides and Recom-
tee onAnalytical Reagents of theAmerican Chemical Society,
mendations issued by the World Trade Organization Technical
where such specifications are available. Other grades may be
Barriers to Trade (TBT) Committee.
used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
2. Significance and Use
accuracy of the determination.
2.1 Color may be indicative of the quality of the solvent
4.2 Purity of Water—Unless otherwise indicated, references
because any color present is due to the presence of contami-
to water shall be understood to mean distilled water or water of
nants.
equal purity.
3. Apparatus
4.3 Cobaltous Chloride—(CoCl ·6H O).
2 2
3.1 Color Comparison Tubes—Matched 50 mL or 100 mL,
4.4 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
tall-form Nessler tubes, provided with ground-on, optically
chloric acid (HCl).
clear, glass caps.
4.5 Potassium Chloroplatinate—(K PtCl ).
2 6
3.2 Color Comparator—A color comparator constructed to
permit visual comparison of light transmitted through tall-
5. Preparation of Color Standards
form, Nessler tubes in the direction of their longitudinal axes.
5.1 Platinum-Cobalt Stock Solution—Dissolve 1.245 g of
The comparator should be constructed so that white light is
K PtCl and 1.000 g of CoCl ·6H O in water.Add 100 mLof
2 6 2 2
passed through or reflected off a white glass plate and directed
HCl (sp gr 1.19) and dilute to 1 Lwith water. This solution has
with equal intensity through the tubes and should be shielded
a color of 500.
so that no light enters the tubes from the side.
1 2
This test method is under the jurisdiction of ASTM Committee D26 on Reagent Chemicals, American Chemical Society Specifications, American
Halogenated Organic Solvents and Fire Extinguishing Agents and i
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