In the USA, emissions from vehicles are regulated by the Clean Air Act. The use of urea SCR NOx control is coming to the US with the implementation of the so-called EPA2010 emission standard, which is effective as of January 1st 2010 and sets the NOx emission limits at 0,3 g/kWh. Diesel Exhaust Fluid (DEF) is regulated by the American Petroleum Institute (API).
There are different emission standards around the world, setting specific NOx and other polluting agents emission limits:
In Europe, current legislation Euro VI has brought the limits to an outstanding reduction of 80% for NoX (Nitrogen Oxides) and 66% for PM (Particulate Matter) compared with previous limits. The new Standard has become effective on January 1st 2014.
In Australia and New Zealand, the emission standards follow those of Europe with a few years delay. Euro IV was phased in from 2007 and Euro V will be implemented in 2010.
In China, the legislation is called National Standard IV and V. From 2008, National VI standard for heavy duty vehicles has reduced NOx limits to 3,5 g/kWh and PM limits to 0,02 g/kWh. This standard has been applied in Beijing since 2008.
In Brazil, the legislation is called PROCONVE – Programa de Controle da Poluição do Ar por Veículos Automotores and will be applied as from 2012. The reagent in Brazil is known as ARLA 32 and this acronym stands for Agente Reductor Liquido Automotivo.