Overview
ISO 22241-3:2017 - Diesel engines - NOx reduction agent AUS 32 - Part 3: Handling, transportation, and storage - sets best-practice recommendations and mandatory requirements for preserving the quality of AUS 32 (aqueous urea solution used in SCR systems) from production until it is filled into vehicle on‑board tanks or other applications. The standard helps ensure reliable Selective Catalytic Reduction (SCR) performance by minimizing contamination, decomposition and physical damage during handling, transport and storage.
Key topics and technical requirements
- Materials compatibility
- Lists recommended materials for surfaces in contact with AUS 32 (e.g., austenitic stainless steels UNS S30400/S31600, titanium, Hastelloy C‑276, PE, PP, PTFE, PVDF) and materials not recommended (carbon steel, copper and copper alloys, aluminium, magnesium, lead‑containing solders).
- Requires testing any material with uncertain compatibility under realistic temperature and contact-time conditions.
- Physical storage and transport conditions
- Temperature guidance: avoid prolonged storage/transport above 30 °C (decomposition risk) and below −5 °C (solidification risk). Protect from sunlight and excessive temperature swings.
- Solidification note: frozen AUS 32 expands ≈ 7%, potentially bursting sealed containers; thawing up to 30 °C restores usability if solids are gone.
- Shelf life
- Minimum shelf life tied to constant ambient temperature:
- ≤10 °C: 36 months
- ≤25 °C: 18 months
- ≤30 °C: 12 months
- ≤35 °C: 6 months
-
35 °C: significant reduction - check batch quality
- Cleanliness and contamination control
- Surfaces in contact must be free of fuels, oils, detergents and trace metals. Final cleaning should use distilled/de‑ionized water and a final rinse with AUS 32 (avoid tap water as last rinse).
- Quality assurance
- Batch traceability with unique batch numbers, sampling, testing and documented procedures, including handling of non‑conforming product and audit practices.
- Packaging and handling procedures
- Guidance for single‑use containers, dedicated and non‑dedicated bulk operations, and sampling requirements.
Applications and who uses it
ISO 22241-3:2017 is essential for:
- Manufacturers and packagers of AUS 32
- Transporters (road tankers, rail cars, IBC/tote handlers)
- Storage terminal and depot operators
- Fleet owners, OEMs and maintenance organizations using SCR systems
- Quality managers and compliance officers responsible for product integrity and SCR performance
This standard helps protect SCR system reliability, reduce NOx control failures and avoid contamination‑related engine or aftertreatment issues.
Related standards
- ISO 22241-1 - AUS 32 Quality requirements
- ISO 22241-2 - AUS 32 Test methods
- Part of the ISO 22241 series covering NOx reduction agent specifications and handling
Keywords: ISO 22241-3:2017, AUS 32 handling, AUS 32 transportation, AUS 32 storage, NOx reduction agent, urea solution, SCR systems.