Fragrances: How to select the right grade?

For cosmetic formulators, fragrances are referred to as fragrance compounds, perfume compositions, or simply fragrance (listed as Fragrance or Parfum on ingredient labels, depending on the region).

When describing fragrance, one of the methodologies we use is to describe the notes of aroma. These include:
 

• Top note: The aroma that is detected immediately on smelling the fragrance after any alcohol solvents have evaporated.
• Body (middle) note: The aroma that is smelled 1-2 hours after the fragrance has been applied.
• Dry out (base) note: The aroma that can be detected the day after the fragrance has been applied. The dry out base note is usually described with a time frame given after which no more change is observed. For example, the dry out note could be attained after 24 hours or up to 5 days.

Fragrances also have principal, secondary, and background notes as well as particular odor characteristics. The strength of fragrances is rated on a scale of 0–6 (0 being odorless and 6 being extremely strong).

These terms are used in reference to the aromas that can be detected using a smelling strip. When used together, they provide a comprehensive description of the fragrance profile.

Starting materials for fragrances

Perfumers put fragrance together much like a cosmetic chemist puts a formula together using known materials in various combinations. Then the samples and variants are repeated until they get the aroma just right to suit the client's brief.

To be a perfumer, you need to undertake extensive studies in perfumery. In addition, you need to have an incredibly acute sense of smell. This is not something that can be learned, you either have 'the nose' and the ability to be a perfumer, or not. As a cosmetic chemist, you will order fragrances to suit a brief, but not actually create the fragrance blend.

Fragrances can be composed of 20-100 or more aroma chemicals. These chemicals can be obtained from:

Natural sources: Components, also known as isolates, are extracted from essential oils and can be separated and modified. For example, eugenol from clove oil and limonene and citronellol from citrus oils.

Synthetic sources: Crude oil sources can provide hydrocarbon backbones. These can then be modified to produce a variety of fragrance compounds. For example, several types of aldehydes, ketones, and hydrocarbons. Aroma chemicals are synthetically produced to be identical to those found in natural products for commercial reasons. Cheaper and more consistent quality can be obtained in this way.

Carriers and solvents: These ingredients dissolve fragrance compounds, improve blending, and ensure even distribution in the formulation. They also help adjust fragrance concentration and facilitate the incorporation of fragrance into cosmetic products. Common examples include ethanol, dipropylene glycol (DPG), and triethyl citrate.

Stabilizers and fixatives: These ingredients enhance the stability and longevity of fragrances. They reduce evaporation, protect aroma compounds from degradation, and maintain the intended scent profile throughout the product's shelf life. Common examples include benzyl benzoate, triethyl citrate, and natural fixatives such as resins and balsams.

Fragrance houses are the best source of fragrances, as fragrances contain multiple ingredients. These must be purchased in quantities of at least 1-5 kg. This makes it cost-prohibitive for a small manufacturer to purchase the individual materials for their fragrance creation. The cost to purchase and hold such large quantities of multiple chemicals is higher, as only a small portion of these would get used in standard fragrance developments.

With a clear understanding of fragrance composition and sourcing, let's explore how to choose the right fragrance and integrate it effectively into your formulation.

One of the first things a consumer does when trying a new product is smell it! Aroma is also one of the strongest evokers of emotion and memory, as well as a primal indicator that impacts later impressions of a product. Getting it right can greatly enhance consumer acceptance, while getting it wrong can have a negative effect.

While a fragrance may seem like a small component of a formula, it delivers a powerful message about your brand. Thus, you must approach fragrance from both a selection standpoint and a technical formulation perspective.

Considerations for fragrance selection

When determining the right type of aroma profile for your product, consider how the scent will interact with consumer psychology and brand identity:

• Benefits of the product: Scent can deliver tangible benefits experienced directly during use (e.g., an intense aroma of freshness). It can also have intangible benefits, where it adds to imagery perception and is attractive to a certain sector of the market.
• Features of the product: Consider if an aroma is used to cover the base smell of a product or add substantivity. A lasting aroma is added to enhance the product's appeal.
• Signal attributes: The aroma provides an immediate impression of the product's purpose. For example, fruity fragrances convey a sense of fun, in contrast to more classic aromas that suggest upscale or luxury products.
• Branding of a product range: Scent enables the grouping of product extensions through a shared aroma profile. For example, body washes, lotions, and perfumes are used to layer a fragrance or match aromas for a shampoo and conditioner.

Here is a simple example of how these aspects build a story about your products: 
 

Product	Benefits	Features	Signal attributes	Branding
Budget body lotion	Tangible: Subtle, lasting fragrance. Intangible: Simple fragrance structure that smells nice.	Subtle, substantive fragrance; type of odor dependent on target market	Would depend on the target market	General body care fragrance; could match a companion shower gel or body scrub
High-priced face cream	Tangible: Subtle aroma from fragrance or essential oils. Intangible: Complex aroma structure, adding to the perception of quality.	Subtle aroma; classy and may also be modern aroma	Classic or more unique aroma; actual notes would depend on the target market	Complex aroma which may or may not be paired with other facial care products in the company's range
Explore 4.4K+ fragrances in the Master Catalog - Compare products from various suppliers, access technical information, or order samples

Technical formulation brief for the fragrance house

Generally, as a product formulator, you will not be involved in the actual chemical synthesis of a fragrance compound. Instead, your role is to translate your strategic choices into a highly specific technical brief for a fragrance company.

To engineer a scent that is chemically stable, safe, and effective in your specific base, the fragrance chemist will require detailed answers to the following criteria:

1. Purpose of the fragrance 

    

   • Product vehicle: Provide a list of the types of products the fragrance will be used in. Will it be used in just one product, or a range of products?
   • Odor masking: Is the fragrance to cover undesirable smells in the base product on the body?
   • Aesthetic benefits: What tangible and intangible benefits do you want from the fragrance?
   • Substantivity: How substantive does it need to be? Choose from 220+ fragrances with substantivity in the Master Catalog.

2. Uniqueness of product 

    

   • Custom vs. off-the-shelf: Do you want a unique smell for the product, or are you happy to use a more off-the-shelf variety?
   • Fragrance duplication: Do you want to copy another fragrance? Sending samples of fragrance benchmarks to the fragrance house is an excellent guide for the fragrance chemist.
   • Naturality requirements: How natural do you need the end product to be? Do you need a natural fragrance from all-natural isolates, or is it okay to contain synthetic components?

3. Application of the product(s)

    

   • Exposure type: Are these products going to be washed off or left on the skin?
   • Sillage/lingering: How strong do you want the lingering fragrance to be, after the product has been applied?
   • User demographics: Is this fragrance to be used on babies, children, or adults? This drastically impacts safety and regulatory limits.

4. Formulation characteristics

    

   • pH environment: What is the pH of the products the fragrance will be used in?
   • Climate stability: What is the climate the product will be shipped to or sold in?
   • Packaging interactions: What packaging is being used? Is UV discoloration an issue? Is oxidation through hot climates and clear packaging a risk?

5. Target market 

    

   Provide a brief overview of your target market. This should include information on their age, income, employment, and interests. For example, professional women aged 35-40, earning >60K US dollars per annum. Interests include socializing with other like-minded women/shopping/holidays. This gives the fragrance chemist an idea of who should be attracted to the fragrance.

6. Cost 

    

   Provide a cost frame and quantity you require to the fragrance company so they can formulate a fragrance to suit your needs. Make sure to also provide them with the percentage it will be used in finished product/s, so they know how intense the aroma of the finished product needs to be.

7. Lead time

    

   • How long will it take to get the product prepared and sent to your warehouse?
   • Is this time frame suitable for the project? Consider not just the time you need in formulating, but also the time needed in manufacturing.

Utilizing off-the-shelf modifications

Modifying 'off-the-shelf' blends provides a cost-effective way of getting a relatively unique and tested product. It allows a short time frame and smaller purchase quantities (typically 1kg+).

Fragrance companies have a variety of 'off the shelf' blends they tend to supply for cheaper products. What they can do in many cases is add a few different fragrance chemicals to the base blend to create something new and relatively unique for your needs.

By modifying an 'off-the-shelf' blend in this way, the fragrance company is able to provide you with a fragrance to suit your requirements, in smaller quantities, individualized to your needs, at a moderate cost.

Checklist for your final order

Before submitting your request to a fragrance house, ensure your brief contains the following summary points:

With your fragrance selected and ordered, the next critical step is understanding the concentration limits and regulatory requirements that govern its safe use.

Concentration limits

Fragrances can be potential irritants, so their use must be within certain limits. In order to maintain safety and provide an aroma of suitable intensity, fragrances should be used in products within set amounts.

As a general guide, products used on the face should contain less fragrance than those used on the body. Fragrances should be carefully selected to ensure they have low irritancy profiles. The skin coverage and type of person the product will be used on must also be considered. For example, baby lotions that get applied over most of the baby's body should contain far less fragrance than a product applied to the legs of an average adult.

A typical guideline is to always check with your fragrance supplier. This is because the concentration of the fragrance they supply could mean different input rates than those suggested here:

• Face products: Up to 0.2% fragrance
• Body products: Up to 0.5% fragrance
• Wash-off products: Up to 0.6% fragrance
• Around the eyes and mucous membranes: Up to 0.1% fragrance
• Baby products: Up to 0.1% fragrance

Once the fragrance limit is verified, you need to learn how to incorporate the fragrance appropriately.

EU regulations on fragrances

In the EU, under the Cosmetics Regulation (EC) No 1223/2009, fragrance allergens listed in Annex III must be individually declared on the label when present above 0.001% in leave-on products or 0.01% in rinse-off products.¹

Following Regulation (EU) 2023/1545, this list has been expanded to more than 80 substances, with new products required to comply from July 31, 2026, and existing products by July 31, 2028.² 

The following steps must be performed:

• Checking the SDS of the individual essential oils and/or fragrances to see if the allergen is stated
• If no allergens are stated, request specific allergen information from the supplier. It is a regulatory requirement that they provide this information to you
• Sum the allergen content where present across more than one material
• Compare the total against the 0.001% (leave-on) or 0.01% (rinse-off) threshold.
• If exceeded, the allergens must be declared on the label.

After confirming your concentration limits and regulatory compliance, you can move on to the practical process of adding the fragrance to your formulation.

Fragrances are almost always supplied in a liquid form. If they are resinous, they will first need to be mixed in a suitable quantity of carrier oil to become more liquid. Fragrances can be oxidized or destabilized by unsuitable conditions.

Before adding fragrances, the following must be ensured:

• The pH of the product is not going to adversely affect the fragrance. If you need a fragrance for a product that has an extreme pH (e.g., a depilatory product), then you should let the fragrance house know this as part of the brief.
• Temperature is even throughout the product and is below 40°C.
• Mixing of the product ensures there will not be any hot spots or uneven distribution of acids or bases, which may still be able to react with the fragrance.

Also, make sure that the fragrance is evenly dispersed throughout the entire product. To ensure this, you could mix the fragrance with:

• Surfactant (in the case of a foaming product)
• Solubilizer (if being added to water or a gel)
• Adding after an emulsion has cooled down (if adding to a cream, lotion, or conditioner)

Fragrances will not normally need additional antioxidants added to the final formula. They normally come with antioxidants, such as, butylated hydroxyanisole (BHA), or butylated hydroxytoluene (BHT) already present to ensure they have a good shelf life. 

The most important thing to remember with fragrance is the power it can have over the success of your product. Make sure you work with a fragrance house and perfumer who really understands your brief, target market, the needs of the product, and what you are trying to achieve, as it can make all the difference when it comes to product sales.