Overview
ASTM D5309-22: Standard Specification for Cyclohexane 999 establishes the requirements for a high-purity grade of cyclohexane, known as "cyclohexane 999." This international standard is maintained by ASTM International and ensures that cyclohexane 999 meets stringent criteria for purity and suitability in industrial and specialty chemical applications. The specification outlines specific limits for common impurities, color, appearance, sulfur content, and distillation characteristics, supporting quality and consistency in production and supply.
Key Topics
- Purity Requirements: The standard specifies a minimum purity of 99.90% by weight, ensuring cyclohexane 999 is suitable for sensitive applications.
- Impurity Content: Maximum allowable concentrations are set for:
- Benzene (50 mg/kg)
- n-Hexane (200 mg/kg)
- Methylcyclohexane (200 mg/kg)
- Methylcyclopentane (150 mg/kg)
- Sulfur (1 mg/kg)
- Physical Properties:
- Appearance must be free of haze and suspended particulates.
- Maximum Platinum/Cobalt color scale rating of 10.
- Controlled distillation range, ensuring consistent boiling behavior.
- Test Methods: Referenced analytical methods include gas chromatography and ultraviolet fluorescence for accurate measurement of purity, impurities, color, and sulfur content.
- Safety and Compliance: The standard directs users to consult OSHA regulations, supplier Safety Data Sheets (SDS), and local guidelines regarding safe handling and regulatory compliance.
Applications
Cyclohexane 999 is widely used where high chemical purity is critical:
- Chemical Synthesis: Serves as a precursor or solvent in the production of nylon intermediates (such as adipic acid and caprolactam) and other specialty chemicals.
- Pharmaceutical Manufacturing: Supports processes that require highly pure solvents to avoid contamination and ensure product integrity.
- Analytical Laboratories: Essential as a reference material and high-purity solvent for chromatography and spectroscopy.
- Quality Control: Used in calibration, validation, and process control in manufacturing environments where trace impurities can affect outcomes.
This specification helps manufacturers, suppliers, and end-users to reliably select cyclohexane 999 that meets established benchmarks for quality and performance.
Related Standards
Several ASTM standards and practices are referenced within ASTM D5309-22 to support test methods and procedures:
- ASTM D850 - Test Method for Distillation of Industrial Aromatic Hydrocarbons and Related Materials
- ASTM D3437 - Practice for Sampling and Handling Liquid Cyclic Products
- ASTM D5386 / D8005 - Test Methods for Color of Liquids
- ASTM D7183 - Test Method for Determination of Total Sulfur in Aromatic Hydrocarbons
- ASTM D7266 / D7871 - Test Methods for Analysis of Cyclohexane by Gas Chromatography
- ASTM E29 - Practice for Using Significant Digits in Test Data
- ASTM E2680 - Test Method for Appearance of Clear, Transparent Liquids
OSHA regulations regarding safe handling and exposure limits for chemicals are also cited for ensuring workplace safety.
Practical Value
Implementing ASTM D5309-22 ensures:
- Consistent Quality: Buyers and suppliers have a clear benchmark for cyclohexane 999 purity and properties.
- Regulatory Compliance: Products conform to international safety and quality standards.
- Process Efficiency: Using high-purity cyclohexane minimizes risk in sensitive industrial, laboratory, and pharmaceutical processes.
- Traceability: Clearly defined analytical methods and stringent limits support traceability and quality assurance.
By referencing ASTM D5309-22, organizations can confidently specify cyclohexane 999 fit for use in applications demanding reliable chemical quality and safety.