A branched-chain hydrocarbon produced by certain zooplankton, one of the many natural hydrocarbons found in marine food webs. Pristane enters the diet principally through fish and marine oils, where it occurs as a minor component of the unsaponifiable fraction. For food analysts it is of interest as a marker compound: its presence and ratio to other hydrocarbons can help characterize marine oils and detect adulteration or contamination with mineral oils. It is chemically stable and of low acute toxicity at the trace levels encountered in foods, so its significance is analytical rather than toxicological.