When walking through supermarket aisles, it’s common to see customers trying to smell the products before taking them home, making fragrance a key factor in consumers’ purchasing decisions.  

A fragrance can evoke sensations, emotions, and even memories. In this way, olfactory stimuli trigger reactions that create emotional connections with the product.

But have you ever stopped to think about how this component works? Keep reading to learn more about the use of fragrances in sanitizer and cosmetic formulations. 

What Are Fragrances? 

Before we move on to more technical definitions, it’s helpful to clarify the difference between two terms that often cause confusion: aroma and fragrance. You’ve certainly come across these two words in your daily life, and it’s very likely that you’ve even used them interchangeably. But are these two terms really equivalent? 

In short, the answer is no—even though the two are quite similar to a certain extent. Our sense of smell is very complex, allowing us to recognize thousands of different odors and interacting with our other senses. And it is this complexity that allows us to distinguish an aroma from a fragrance. 

Given this complexity, fragrance is the term used when only the sense of smell is activated—that is, when we’re talking about something that makes us perceive only a smell. However, it’s very common for a scent to end up stimulating other senses: you know that smell of freshly roasted coffee that brings back that memory of your grandparents roasting beans when you were a child? Or that scent of pine and spices that transports you to a Christmas dinner? When this blend of senses occurs—or this connection to a memory or feeling—a fragrance becomes what we call an aroma. 

With that in mind, we can see why these two terms are commonly used as simple synonyms. And by understanding this distinction between them, we open the door to the vast world of perfumery, fragrances, and aromas: a truly memorable scent should be more than just a fragrance; it should always awaken more than just our sense of smell. 

Now that we have these definitions, we can move on to a slightly more technical definition. 

The fragrances we encounter are usually complex compositions produced by mixing various molecules, such as esters, alcohols, aldehydes, ketones, and terpenes. Each molecule has unique physicochemical characteristics, such as volatility, solubility, and odor. The combination of these different characteristics of each molecule in varying proportions creates the olfactory identity of each fragrance. 

Of the characteristics listed above, it is essential that fragrances contain volatile substances—those that evaporate easily and allow their molecules to mix with the air. As soon as we inhale, we draw these molecules into our nose, where they are absorbed by the nasal tissue and translated into smells by our brain. 

Knowing this, it is easy to see that each fragrance will be unique due to its specific composition and the relative proportions of each component; it may consist exclusively of a single molecule or of a blend of various substances.

Initially, fragrances were composed exclusively of essential oils, which are natural substances found in plants or even animals. However, over time, various aromatic substances began to be synthesized, leading to the emergence of synthetic essences.

Understanding Fragrances

Based on the definitions presented above, we can begin to imagine the complexity we can bring to fragrances, especially when we apply them to perfumery, where compositions rarely consist of just a few substances. 

One way to try to understand a fragrance is by classifying it within the olfactory pyramid. This pyramid is a way of classifying its structure, dividing it into three parts: the top notes, the middle notes, and the base notes. 

Top notes, as the name suggests, refer to the sensory notes we perceive immediately upon approaching a fragrance. They are the ones that first hit our sense of smell. The substances that create this type of note tend to be light and highly volatile, and are generally citrusy and fresh, reminiscent of lemon, orange, or tangerine. Top notes are responsible for a fragrance’s first impression and are usually what capture your attention. 

However, since these top notes are very fleeting, they should not be considered the main notes. Shortly after they fade, you should notice the heart notes, which are known as the true personality of a fragrance. They tend to be slightly heavier than the top notes and also last much longer. Heart notes are generally fruity, floral, or spicy. 

Finally, the heavier, less volatile substances make up what we call the base notes. As the name suggests, these notes don’t usually stand out much at first, but over time they become more noticeable. The substances used to create base notes are typically woody, resinous, musky, or vanilla-like. 

This concept of the olfactory pyramid is useful for understanding how a fragrance evolves, and it is also a tool that helps us choose the ideal fragrance by recognizing the importance of each type of note.

The Role of Fragrances

In cosmetic and cleaning product formulations, fragrances can serve more than one purpose and play a significant role in this field. 

• Masking the odor of other components in the formulation: Within a formulation, some raw materials may have odors that are characteristic but unpleasant. By adding fragrance to the formulation, the unwanted odor is masked, making the product pleasant.
• Promote the perception of cleanliness: Consumers may be influenced by the fragrance’s distinctive scent, giving them the impression that the cleaning was more effective. Certain fresh scents are commonly associated with cleanliness and well-being, influencing the user. 
• Evoking emotions: Different fragrances can evoke different emotions and sensations in people, such as relaxation, joy, or energy.
• Describe the product: Cleaning products are often associated with common natural scents, such as lavender, lemon, pine, and floral. Therefore, a fragrance with notes that evoke the characteristic scent of the item described on the label is used.   

The Influence of Fragrances on Formulations 

The use of fragrances can affect the physicochemical properties of formulations. 

One of the properties most affected by fragrance is viscosity; for the same formula, it is possible to obtain significantly different viscosities simply by changing the fragrance. 

In addition, the stability of the formula may also be affected simply by changing the fragrance. These changes can be explained by the fact that each fragrance is unique and, as noted earlier, is generally a combination of various compounds. Therefore, even if two fragrances have similar scents, they may have completely different chemical compositions and distinct properties. 

In the fragrance industry, it is also very common to encounter so-called water-soluble fragrances, which, despite their name, are not actually soluble in water. What happens in this case is the addition of surfactants—such as nonylphenol, for example—to the fragrance composition so that, upon contact with water, the oily components are immediately emulsified, facilitating their incorporation during the production process. However, these surfactants tend to break down viscosity and reduce the solubility of some formulations, causing instability. 

Another important point to highlight concerns diluted fragrances. Since fragrances are, for the most part, high-value products, many manufacturers and distributors dilute them with lower-cost solvents to “cut costs,” which ultimately reduces their effectiveness. In addition, these solvents also tend to break down viscosity and cause instability in some formulations.  

Therefore, a good tip when purchasing a fragrance is to request what is known as pure oil. This means it contains neither surfactants nor solvents. In this case, the emulsification process can be carried out during manufacturing using the components best suited to the specific formulation. The product’s price will be higher; however, the dosage required will be significantly lower, resulting in a better cost-benefit ratio. 

Isogen E-TEC: Discover Macler’s Solution for Emulsifying Fragrances 

Most essential oils and synthetic essences are nonpolar molecules or molecules with low polarity, which means that most fragrances are practically insoluble in water. This creates the need to emulsify the fragrance in order to incorporate it into aqueous systems. 

At Macler, Isogen E-TEC has emerged as an efficient alternative for emulsifying a wide variety of fragrances, resulting in cost savings without affecting the levels of active ingredients, fragrance, and colorants in the products—factors that are crucial to performance and purchasing decisions. 

By using this product, it is possible not only to use a low dosage but also to replace ethoxylated nonylphenol, a substance commonly used for this purpose but one that has been proven to be toxic to the environment. Click here to learn more. 

• From an environmental standpoint, Isogen E-TEC is a rapidly biodegradable, vegan, phenol-free, ethoxylate-free product made from renewable sources.  
•  It is less expensive and, in most cases, requires a lower dosage than traditional emulsifiers, which also reduces the cost per application in the product. 
•  In addition to all the benefits mentioned above, it is also very easy and convenient to work with. 
• Click here to see a comparison of fragrance emulsions containing nonylphenol, ethoxylated fatty alcohol, and Isogen E-TEC 

Far beyond perfumes

Fragrances in cleaning products and cosmetics do more than just provide a pleasant scent. They can mask odors, create a sense of identity, and even evoke emotions. When choosing a product, it’s important to consider your needs and preferences, as well as to pay attention to the fragrance’s composition and how to use it properly. 

Macler's SmartLab can assist your laboratory with this application and with the development of new formulations, always with a focus on improving your processes and your company's performance. 

Are you curious and want to learn more about how we can help you? Get in touch with us and speak with one of our experts.