If any substance is added as part of the production process, the
finished product will only be eligible for the biodiesel duty rate
if it meets the fiscal definition.
NB The use of any mineral (hydrocarbon) oil additives during the production process is likely to result in a finished product that does not fully meet the fiscal definition for biodiesel. These additives have no ester value and if a higher proportion than 3.5% is used, the fuel will not meet the fiscal specification. (See also ‘diesel quality’ HCOBIG10500 ).
If a mineral (hydrocarbon) oil additive, which has not been charged with excise duty, is added to the finished biodiesel the resulting product will be dutiable as a bioblend.
Some producers mix small quantities of tied oils, such as turpentine, dipentene and limonene, in their biofuel: