Volatile compounds often used in perfumes and in preservatives which can be toxic and cause allergic reactions.
In organic chemistry, an aldehyde (/ˈældɪhaɪd/) is an organic compound containing a functional group with the structure R−CH=O. The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are common and play important roles in the technology and biological spheres.