Classic intense-lemon scent, that will be familiar to anyone who has used lemongrass oil, very useful for prolonging and enhancing citrus effects but generally only in low dosage.
Arctander has this to say about it: “Widely used as a powerful Lemon-fragrance chemical, but suffers from poor stability in many types of functional products. Air, alkali and daylight have a deteriorating influence upon this aldehyde, and Anthranilates, Indole, Quinolines and many other perfume chemicals form dark colored reaction products with Citral. Accordingly, its use is somewhat restricted and there is a low limit of concentration of Citral for most perfumes.
Olfactory research during the past few decades has confirmed that Nitriles often have odors similar to those of the corresponding Aldehydes, and this is how Geranyl nitrile (see that monograph) has become increasingly popular in perfume compositions.”
Safety Data Sheet