This European Standard specifies requirements and test methods for fast pyrolysis bio-oils for boiler use at industrial scale (>1 MW), not for domestic use. Two different grades are specified. It is recommended to draw attention to differences especially in those properties, which may have an effect on the required flue gas treatment system, such as ash, nitrogen, and sulfur content. Local regulations determine the need for the required flue gas treatment system. In addition to the quality requirements and test methods for fast pyrolysis bio-oils, further instructions on storage (Annex A), sampling, and materials compatibility (Annex B) are given. NOTE For the purposes of this European Standard, the term % (m/m) is used to represent respectively the mass fraction.