The viability of the use of ortho-cresol as a bio-blendstock or antiknock additive from lignocellulosic biomass is assessed; Ignition delays of ortho-cresol within blends with iso-octane are measured with the ULille rapid compression machine, and compared with results from the literature; It is shown that ortho-cresol has a strong inhibiting effect on the reactivity towards ignition, most notably in the Negative Temperature Coefficient region; This effect is found to originate from competition with iso-octane on the OH radicals, where the reactivity of ortho-cresol with these radicals does not lead to radical chain-branching.