As you are aware, in order to gradually reduce air pollution, Directive 97/68/EC, which established requirements relating to emission limits (stages I, II, IIIA, IIIB and IV) and type-approval procedures for engines for non-road mobile machinery, was adopted in 1997.
In January 2017, Directive 97/68/EC was repealed and superseded by Regulation (EU) No 2016/1628, which establishes emission limits for gaseous and particulate pollutants (known as Stage V) for engines of non-road mobile machinery, as well as administrative and technical requirements relating to type approval. This regulation will affect products marketed from 1 January 2019. However, it provides for a ‘transition’ period, in which equipment with engines manufactured in 2018, so not Stage V-approved, may be sold.