ISO 5313:2026

Overview

ISO 5313:2026 details the standardized method for determining the oil retention of high nitrogen content, straight ammonium nitrate fertilizers. This international standard specifies a procedure for measuring the gas oil retention in solid fertilizers, specifically those that are prilled or granular and do not contain materials soluble in gas oil. Accurate oil retention measurement is critical for assessing fertilizer porosity and handling characteristics, which affect storage, safety, and application performance.

Key Topics

• Scope: Applies to prilled or granular, high nitrogen straight ammonium nitrate fertilizers free of gas oil-soluble materials.
• Oil Retention Test: Defines the process for immersing fertilizer samples in gas oil, removing excess oil, and calculating the percentage retained based on mass difference.
• Apparatus:
  • Laboratory balance (precision to 0.01 g)
  • Standard test sieves conforming to ISO 3310-1
  • Beaker, funnel, and specific filter paper
• Reagents: Specifies quality criteria for gas oil used in the test, including viscosity, density, and sulfur content.
• Results Expression: Oil retention is expressed as a percent by mass; repeatability and reproducibility guidelines help ensure reliable results.
• Reporting Requirements: Includes specific instructions for documenting observations, methodology, and any deviations.

Applications

• Fertilizer Quality Control: Ensuring consistent physical properties in ammonium nitrate fertilizers, which impacts their behavior during handling, transport, and field application.
• Safety and Handling: Oil retention relates to granule porosity and potential risks in storage, such as caking, dust generation, and chemical instability. Higher porosity can affect how these fertilizers absorb moisture or interact with other substances.
• Regulatory Compliance: Following ISO 5313:2026 helps manufacturers, laboratories, and regulators meet both national and international requirements for fertilizer quality assessment.
• Product Development and Optimization: Fertilizer producers can use oil retention measurements to refine formulation and granulation processes, targeting improved performance and safety.
• International Trade: Standardized testing methods enable comparability and trust in product quality between suppliers and buyers across different regions.

Related Standards

• ISO 3310-1: Test sieves - Technical requirements and testing for sieves of metal wire cloth used in sample preparation.
• ISO 14820-2: Fertilizers and liming materials - Guidelines for sampling and sample preparation in laboratory testing.
• ISO/TC 134: The technical committee focused on fertilizers, soil conditioners, and beneficial substances, which oversees relevant standardization initiatives.

Practical Value

Adhering to ISO 5313:2026 ensures that results for oil retention in ammonium nitrate fertilizers are repeatable and reliable, regardless of where the test is conducted. This supports:

• Consistent product quality in large-scale fertilizer production
• Efficient communication of quality data among manufacturers, laboratories, and regulatory authorities
• Enhanced safety management during transportation and storage
• Recognition in global markets for products tested according to internationally accepted procedures

Utilizing the ISO 5313:2026 standard helps foster trust throughout the fertilizer supply chain and supports best practices in agricultural chemical management.