ISO 22241-5:2019

Overview

ISO 22241-5:2019 specifies the refilling interface for the NOx reduction agent AUS 32 (commonly called AdBlue®) for passenger cars and light commercial vehicles using Selective Catalytic Reduction (SCR). The standard defines the functional and geometric requirements of the on-board and off-board refilling systems to ensure compatibility, safety and minimal nuisance (spill, odour, pressure) when dispensing AUS 32 into vehicle tanks.

Key topics and technical requirements

• Scope: Intended primarily for passenger cars and vehicles up to 3.5 t gross vehicle mass, but applicable to larger vehicles as needed.
• Refilling system definition: Includes on-board components (filler neck, filler cap, tank) and off-board equipment (storage, pump, hose, filler nozzle); canister filling (1–10 L) is defined separately.
• Flow rate: Maximum flow rate range for refilling 5–10 L/min (except canister and production-line filling).
• Automatic shut-off: Required; residual flow after automatic stop ≤ 50 mL.
• Spillage: Less than 0.4 mL per refilling (measured with filler neck angle ≥ 30°).
• Pressure control: Filler neck pressure must be within ±3 mbar at 5 s after start; return to ambient at end of filling.
• Ventilation / odour: During refilling, ammonia concentration at the filler neck must not exceed 15 mg/L.
• Temperature & freezing: On-board components designed for approx. −30 °C to +80 °C; off-board −20 °C to +40 °C. AUS 32 freezes at about −11.5 °C and expands ≈7% - protection and thawing considerations required.
• Misfilling prevention: Filler neck and nozzle geometries prevent fuel being dispensed into AUS 32 tanks and vice versa.
• Materials & cleanliness: Materials in contact with AUS 32 must be compatible (see ISO 22241-3); high manufacturing cleanliness is required.
• Mechanical interface: Filler neck uses a buttress thread S 36 × 4 with specified sealing surface; threads designed to withstand at least 5 Nm torque. Screw-coupled nozzles should limit torque to 5 Nm and include internal vapor recovery.

Applications and who uses it

• Vehicle manufacturers and design engineers (filler necks, caps, on-board tanks)
• Component suppliers (nozzles, hoses, seals)
• Service-station and fleet operators (off-board dispensing equipment, refuelling procedures)
• Testing laboratories and conformity assessors (spillage, odour, pressure and strength tests)
• Regulators and procurement teams specifying safe, compatible AUS 32 refuelling systems

Related standards

• ISO 22241-1 - AUS 32 quality requirements
• ISO 22241-3 - Handling, transportation and storage; material compatibility and cleanliness
• ISO 22241-4 - Open refilling systems (can be used for some light vehicles)
• ISO 2575 - Symbols for controls and tell-tales
• EN 13012 - Example nozzle standard referenced for automatic shut-off design

ISO 22241-5:2019 helps ensure interoperable, safe and low-nuisance AUS 32 refuelling across vehicle models and refuelling infrastructure - essential for reliable SCR NOx reduction in diesel passenger cars and light commercial vehicles.