Recently, the use of the musk odor in perfumery has been the subject of much lively discussion in the fragranced consumer goods industry. It is therefore, an appropriate topic for perfumers and the consumers of their creations. I would like to summarize the various possibilities, considerations and choices that are open to perfumers when they create fragrances that are safe for today’s market, including a brief description of the versatility and functionality of the various musks, as well as the safety of these ingredients.
Musk-Odor Attributes What is musk odor? Nature’s own musks emanate from insects, vegetation and, primarily, animals, although not all musks have animalic odor. All musks share a rich enveloping smoothness of fragrance usually with modifying or secondary aspects. For some people, there is also a “pure” category, shown in Figure 1 as “simple” or “transparent” to which perhaps, could be added the descriptor, “cool”. The “sweet” musks seem to have a powdery, vanilla character. I will describe, briefly, the molecular shape of these substances that exhibit musk odor. Figure 2 shows the tremendous range and variety of chemical functionalities and structural shapes. Different as they clearly are, they share one common aspect, a primary odor, which we describe as musk. There are one, two, three and fourringed structures. Functionally, we see ethers, ketones, chromans (otherwise known as internal ethers), lactones, alcohols and nitro groups. There are, of the order, twenty manufacturers of musk chemicals around the world. However, not all of the chemicals shown in Figure 2 are commercially available.
One very important factor shared by musks in widely varying degrees is the ability to act as “odor magnets”, “fixatives”, even synergists for other substances. They appear to cling to and extend the life of the more fleetingly odored materials. For example, nature-identical apple fragrance would primarily be comprised of lower molecular weight compounds (mostly esters) that are very volatile and hence not long-lasting. The presence of an appropriate musk (for example HHCB) will enable an apple fragrance to last for a much longer period of time as a single entity. Curiously, the musk note does not overpower the other components in the apple fragrance, even though the HHCB may be present at a higher percentage. Table 1 shows a list of attributes that are either exhibited collectively by the musks or aspects that musks strongly support and complement when skillfully incorporated into a fragrance. As can be seen, this list of attributes is very significant from a marketing viewpoint as it includes a high percentage of the benefits that we need to convey to consumers regarding finished-fragrance products.