This document is intended to inform about the potential technical consequences on engine parts and fuel systems when some types of chemical compounds are used as blending components in unleaded petrol. This document is not meant to intentionally limit market fuel development. The chemical compounds addressed, specifically, in this document are: sec- Butyl acetate (SBA) (CAS 105-46-4), Aniline (CAS 62-53-3); N-Methyl Aniline (NMA) (CAS 100-61-8), N-Ethyl Aniline (NEA) (CAS 103-69-5), and N,N di-Metyl Aniline (DMA) (CAS 121-69-7). Other chemical compounds are not addressed in this document, however attention is drawn to EN 228 which requires that unleaded petrol shall be free from any adulterant or contaminant that can render the fuel unacceptable for use. NOTE 1 This document does not address environmental and/or health related issues. These aspects are beyond the scope of CEN/TC 19 activities. NOTE 2 For the purposes of this document, the term % (V/V) is used to represent the volume fraction, Æ.