Two further elements of the ISO AdBlue standard are due to come into force over the next two years. This means that the ISO standard for urea solution, number 22241, will have four constituent parts when it is complete.

The first two parts of the standard were published in full on 11 October 2006. ISO 22241-1 details the quality requirement of NOx reduction agent AUS 32 (aqueous urea solution, or AdBlue). The second part (ISO 22241-2) governs the test methods through which this quality is determined.

The third element which has been introduced by industry working groups addresses the packaging, transportation and storage of AdBlue. This section is in the form of a working draft (ISO/WD 22241-3) which has several committee and consultation stages to go through before reaching full ISO status by the target date of 31 March 2009. Industry sources told Vent that this part of ISO 22241 is unlikely to differ substantially from the AdBlue handling guidelines drafted by Cefic in Europe.

The fourth constituent part of ISO 22241 concerns the AdBlue refilling interface. This is already published as a draft and has a target publication date a year ahead of part three (i.e. 31 March 2008). This standard will establish the materials and systems which should be used in AdBlue truck filling equipment. Because of the corrosive nature of AdBlue, it is likely that non-spill systems and certain construction materials for the interface will be specified. In spite of the availability of devices to prevent mis-filling, such as the magnetic coupling of the Elaflex nozzle, several cases of engine damage resulting from the dispensing of AdBlue into the fuel tank have now come to light. Such devices may be specified in ISO 22241-4, although industry sources say stakeholders are pushing for a wider variety of equipment to be covered by the standard.