1. For fuels or materials containing RFNBOs, RCFs or synthetic low-carbon fuels for which the operator cannot determine the RFNBO or RCF fraction or synthetic low-carbon fraction in accordance with paragraph 2, the operator shall assume the absence of RFNBO, RCF or synthetic low-carbon fuel and apply a default RFNBO or RCF fraction or synthetic low-carbon fraction of 0 %.

2. The operator shall determine the following calculation factors relating to the composition of fuels based on the mass balance pursuant to Article 30(1) of Directive (EU) 2018/2001:

(i) the zero-rated RFNBO or RCF fraction or zero-rated synthetic low-carbon fraction;

(ii) the RFNBO or RCF fraction or synthetic low-carbon fraction.

By way of derogation from the first subparagraph, if the operator does not want to make use of zero-rating, for the RFNBO or RCF fraction or the synthetic low-carbon fraction other approaches may be used such as a material balance of the blending or production process from which the fuel or material is obtained.