EU Regulation 2016/1628 EURO V, which came into force in September 2016, sets out new emissions limits for combustion engines (gasoline and diesel engines) in non-road mobile machines and devices. The new emissions limits came into force for all STIHL products on January 1, 2019.
The "2016/1628" reference in the type-approval number on your product will indicate whether your STIHL product fulfills the new emissions limits in accordance with EURO V.
In addition, you can find a CO₂ value in accordance with EURO V in the "Products" category of the respective product-specific technical data for your product.
This CO₂ measurement results from testing a (parent) engine representative of the engine type (engine family) over a fixed test cycle under laboratory conditions and does not imply or express any guarantee of the performance of a particular engine.