Peat was an organic substance.
In 2373, to soften the blow of Barry Waddle's referring to Klingons as "foul-smelling barbarians", Julian Bashir and Miles O'Brien reassured Worf. O'Brien told him not to take it personally with Bashir adding that he liked Worf's smell. The engineer referred to it as an "earthy, peaty aroma", prompting Bashir to further suggest "a touch of lilac". (DS9: "Trials and Tribble-ations")