There are currently two UN codes for the transport of crude C4 streams: UN1010 and UN1965. The first one having a butadiene concentration above 40 %, the second one having butadiene concentration below 40 %.

Until beginning this year, the definition for transport via road, rail or ship in EU of crude C4 streams was different but Spain made a request to harmonise these definitions with UN definitions. Following this request, Cefic proposed to develop a multilateral agreement to continue using the old definition for UN1010 in AND, ADR and RID as in Europe: typical concentration of butadiene in crude C4 fluctuates around 40 %.

This multilateral agreement has since been signed by 10 EU countries. Cefic also initiated an action at UN level to lower the concentration limit of butadiene in crude C4 in the definition of UN1010 from 40 % to 20 %. The requested change was accepted, but we are still waiting for final evaluation.