ISO 22241 is the international standard that governs the quality of diesel exhaust fluid, covering production, storage, and handling to ensure the fluid remains effective in SCR systems. The standard specifies requirements for urea content, purity, and appropriate handling to prevent contamination.

What ISO 22241 Standards Cover

ISO 22241 is divided into several parts, each focusing on a different aspect of diesel exhaust fluid quality control:

ISO 22241-1: This section outlines the general requirements for diesel exhaust fluid, including specifications for the urea content and purity. It also emphasizes the need for appropriate storage conditions to prevent contamination.

ISO 22241-2: This part provides guidelines on ensuring the fluid is kept at optimal conditions, avoiding contamination and degradation during storage and transportation.

ISO 22241-3: This section specifies test methods for assessing diesel exhaust fluid quality, including techniques for measuring urea concentration, pH levels, and other essential parameters.

Key Quality Parameters to Test

To ensure diesel exhaust fluid meets ISO 22241 standards and works effectively in SCR systems, several key quality parameters must be regularly tested.

Urea Content: Diesel exhaust fluid must contain 32.5% urea by weight, with the remainder being deionized water. Deviation from this concentration can lead to ineffective emission reduction and potential damage to the SCR system.

Density Measurement: Density serves as an indicator of correct urea concentration and can be measured using refractometers and hydrometers.

Contaminant Testing: ISO 22241 sets strict thresholds for contaminants. Testing protocols typically involve spectroscopy and chemical analysis to detect and quantify impurities.

Material Compliance for Production Equipment

Machinery and storage tanks used in diesel exhaust fluid production must be constructed from ISO 22241-approved materials that do not react with the urea solution. Permissible materials include high-grade stainless steel (such as AISI 316L) and specific plastics including PE-HD, PP, and PTFE.