ASTM D848-23 PDF

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.