Celery Seed Oil is a pale yellow to orange yellow liquid. Its odor is spicy-warm, sweet and rich, “soup-like”, longlasting and powerful, slightly fatty, typical of the odor of the seed (fruit) but less fresh than the odor of the celery plant. The flavor is equally warm and spicy, somewhat burning and very powerful. Celery seed oil is one of the most diffusive odors and one of the most penetrating flavors. The average use level of this oil in flavors would be somewhere between 0.05 and 0.50 mg%, but the Minimum Perceptible is incredibly low: 0.001 to 0.002 mg%. In other words, the typical celery flavor is perceptible in a dilution of one part of celery seed oil in one hundred million parts of a neutral liquid medium. Minor quantities of selery seed oil are used in pharmaceutical preparations where the oil is said to exert a sedative effect.
Arctander, Steffen . Perfume and Flavor Materials of Natural Origin (p. 178).