ASTM E1673-21 PDF

Overview

ASTM E1673-21 is the international standard test method for determining the percent suspensibility of dry pesticide formulations. Developed by ASTM, this method is vital for assessing the dispersion stability of products such as wettable powders, water-dispersible granules, and similar materials. Percent suspensibility indicates how well a solid pesticide formulation remains suspended in water and is critical for ensuring the efficacy and safety of pesticide applications.

The standard outlines precise laboratory procedures for sample preparation, mixing, settling, and evaluation. It is designed for use by quality assurance laboratories, formulation chemists, and regulatory agencies, providing a reliable basis for comparing products and ensuring compliance with industry requirements.

Key Topics

• Purpose and Scope

  • Specifically applies to dry pesticide formulations, though it can be used with other materials if suitable.
  • Not recommended for formulations with soluble or volatile components, liquids, or ingredients that rise to the surface or decompose under test conditions.
  • Stipulates use only with SI units.

• Test Procedure

  • Involves mixing a weighed dry sample into standardized water, agitation, settling, and analysis of the remaining suspended solids.
  • Two options for measurement: evaporation and centrifuge/evaporation.
  • Results reported as percent suspensibility.

• Apparatus and Materials

  • Top-loading balance, specific beakers and mixing cylinders, magnetic stirrer, centrifuge, vacuum apparatus, and oven.
  • Rigorously defined reagent water and synthetic waters for reproducibility.

• Repeatability and Reproducibility

  • Duplicate samples are mandatory for accuracy.
  • Results from different laboratories or analysts considered suspect if differing by more than 3% absolute.

• Safety Considerations

  • Users must review MSDS and product labeling for proper personal protective equipment and risk mitigation.
  • Disposal of test materials must conform to safety and environmental standards.

Applications

• Quality Control: Central for manufacturers of pesticides and agrochemicals to verify formulation stability and performance before market release.
• Product Development: Used during R&D to optimize formulations for better dispersion and field application.
• Regulatory Compliance: Meets the requirements of national and international agencies for pesticide registration and approval.
• Comparative Analysis: Enables benchmarking against competitors and aids in troubleshooting formulation issues.

This method is essential wherever consistent performance of dry, water-dispersible pesticide formulations is required, both in laboratory and industrial environments.

Related Standards

• ASTM D1126: Standard Test Method for Hardness in Water - referenced for checking water hardness in sample preparation.
• ASTM D1193: Specification for Reagent Water - used for establishing standard water quality in testing.
• CIPAC MT-73: For auxiliary methods in hardness titration.
• ISO Standards for Pesticide Formulation Testing: Related international protocols for evaluating similar physical-chemical properties.

Keywords

percent suspensibility, suspension, dry pesticide formulations, water dispersible granules, wettable powders, dispersion, ASTM E1673, product quality, pesticide testing, formulation stability, analytical chemistry, laboratory standards

ASTM E1673-21 is a foundational test method within the agrochemical industry, supporting product integrity and regulatory acceptance worldwide. For official use, always refer to the current standard as issued by ASTM International.