fragrance oil (2)

Everything about fragrance oil

While the packaging is considered the first attraction (and indeed it is), the scent gives a product a more profound connotation. Whether a cosmetic is good or bad, and whether consumers welcome it, often has a lot to do with the fragrance.

Fragrance oil is a complex synthetic (i.e. artificially manufactured) product that can be 100% chemically synthesized or semi-synthetic(chemically synthesized+ natural essential oil). And what is not chemically synthesized is called essential oil. Based on natural conditions and price, the use of fragrance oils still accounts for the most significant proportion in cosmetics, here we focus on fragrance oil.

Aroma elements(odorant)

Aroma element is the raw material of fragrance oil. The source can be natural(essential oil, extracts) or synthetic(aroma chemicals), synthetic aromas are also divided into two types.

One is that exists in nature, and after its structure is determined through chemical analysis, then chemically synthesized using chemical raw materials. The synthesized chemical structure is identical to the natural aroma compound. This raw material is used in most fragrance oil which can be composed of hundreds of that.

The other is that do not exist in nature and are chemically synthesized to create scent that is similar to the natural substance but has the same pleasant scent.

Aroma compounds are rarely used alone but are usually blended into fragrance oil and then used in various products.

The composition

Fragrance oil is basically composed of four kinds of aroma compounds.


Also called base flavoring agent, determines the type of fragrance scent, and is an absolutely necessary component to give the characteristic scent, its smell forms the main body and outline of the fragrance aroma.


Also known as and blending agent, its role is to harmonize the scent of various components, so that the base is more prominent, rich, and rounded.


It is the technique of using one odorant to modify the other to give a specific aroma, we can call that odorant is modifier. it works in small amounts to set off the base and make the aroma more beautiful.


Also known as a retention agent, it is not volatile easily and inhibits the volatility of other odorants, thus slowing down the volatility of the entire fragrance oil. Its function is to keep all odorants closely together and keep their volatility rate even, always emitting scent in the same condition. It can be a single odorant or a mixture of several single odorants.

Fragrance note

According to the different volatility and retention time of the odorant in the fragrance formula, the fragrance note is broadly divided into three segments.

Top note

It is the initial scent, which is smelled immediately when the fragrance oil is opened. High volatility, and is generally considered to evaporate and dissipate in less than two hours, which is the first impression of the fragrance. Such citrus, rose oil, fruity, and light green are in this range. The top note can give people the initial beautiful feeling, and make the fragrance infectious, but it does not represent the characteristic aroma of the fragrance.

Middle note

Also known as the body note, the volatility of medium. After the first scent pasts, followed by a rich scent, it continues for 2 ~ 6 hours, which is an important part of the fragrance characteristics. Jasmine, rose, lily of the valley, lilac, and aldehydes are suitable for the middle note. The middle note is the main component of a fragrance, it represents the main scent.

Base note

Also called tail note, late note or residual fragrance, fragrance trace(dry out), low volatility and rich retention, lasts more than 6 hours or a few days or months. It represents the entire aroma profile of the fragrance.

The process requires that the change of aroma between segments is smooth and continuous, that is to say, the boundary between segments is not as clear as the map, but like the passage of time, unconsciously from morning to noon, from noon to evening. In the middle note, there must be a little top note remaining. In terms of artistry, the aroma must be delicate, elegant, and original. In the technical aspect, it must have certain intensity, harmony and naturalness, strong lasting power, and so on.

Fragrance wheel

If you are not familiar with scents, the process of finding out what you like can be intimidating. This is the time when the fragrance wheel can be of great help.
Developed by perfumer Michael Edwards, the fragrance wheel is a circular chart divided into four main categories: floral, oriental, woody, and fresh, each with its own sub-families. These scents are grouped according to their similarities and differences to show how they relate to each other.

It is important to note that the classification of perfumes is not strictly and not fully approved. You can classify fruity as floral or as fresh.

fragrance wheel(1)


The most common scent, almost all fragrances will contain floral notes, even as a secondary aroma to soften the entire fragrance. Commonly used for females, it can also be added as a base note to make it suitable for men, perfect for spring and summer.

  • Fruity: A variety of sweet and edible fruit odors, with a sweet smell.
  • Floral: It focused on keeping the freshness of flowers, smelling like freshly picked flowers.
  • Soft Floral: Soft floral is the sweetest smelling, softer than other floral, with a powdery scent.


The oriental fragrance family contains a wealth of exotic scents, gorgeous and intoxicating, such as herbs and spices or dry, powdery, resinous, and can even be very sharp, so perfumers tend to tweak them to be softer and more floral.

  • Floral Oriental: The sharp smell of spices appears in the sweetness of the flowers.
  • Soft Oriental: Soft floral and strong oriental aroma, beautiful, warm scent.
  • Oriental: Maintain the true original oriental feeling with sweet, rich, warm and sometimes spicy.


These scents are dry and warm, often long-lasting, and they form the base notes of many fragrances. To lighten the warmth, perfumes sometimes add some fresh scents such as citrus or floral. Traditionally, they are more masculine and have notes of vanilla, pine, sandalwood, birch and thoughtfulness.

  • Woody Oriental: A blend of woody and oriental spicy notes.
  • Woods: Dry, intense aroma.
  • Mossy Woods: Moss is sweet, not as dry as trees, and has an earthy, rich aroma.
  • Dry Woods: Like sun-scorched wood, dry and deep.


They are clean and bright, herbal, citrus and marine all fall into this category. Fresh are paired with spicy to create a more powerful scent.

  • Aromatic: Fresh and natural, zesty smell. Lavender is a good example.
  • Citrus: Has the aroma of citrus fruits, a sharp, zesty smell.
  • Green: Pungent, sharp scent. Like freshly mown grass.
  • Aquatic: Light, airy smells of nature, like rain and seawater.
FamiliesSubfamiliesSuitable forExamples
FloralFruityFemalesPeach, pear, apple
FloralUnisexRose, Lilium
Soft FloralFemalesJasmine, sweet pea, aldehydes
OrientalFloral OrientalUnisexOrange blossom
Soft OrientalFemalesAnise
OrientalUnisexCinnamon, vanilla, musk
WoodyWoody OrientalUnisexMyrrh
WoodsUnisexCedarwood, vetiver, sandalwood
Mossy WoodsUnisexOakmoss, amber
Dry WoodsUnisexVetiver, smoke
FreshAromaticUnisexSage, Lavender
CitrusUnisexMandarin, bergamot
GreenMalesFresh-cut grass, violet leaves, cucumber
AquaticUnisexrain, seawater


The stability of flavors is mainly expressed in two aspects, one is the stability of their own aroma, the other is their physical/chemical properties in the medium are stable or not.

The reason why the stability has received so much attention is that fragrance oil is composed of hundreds of compounds with different molecular structures, all of which are very different in their physicochemical properties and subject to complex changes with each other. Situations happened where fragrance oil is insoluble in a product (yes, there are water-soluble and oil-soluble flavors) or causes discoloration, which is also due to stability.

The reasons leading to the instability of fragrance oil are as follows:

  • Chemical reactions between aroma molecules, such as ester exchange, phenolic condensation, etc.
  • Oxidation of some molecules with air, such as aldehydes, alcohols, unsaturated bonds, etc.
  • Some molecules undergo physicochemical reactions when exposed to light, e.g. ketones, nitrogen-containing compounds, etc.
  • Some components are incompatible with the product, such as by the influence of pH value, there may be saponification, hydrolysis, surfactant incompatibility, etc.
  • Reaction with the packaging material.

In short, fragrance workers must be very familiar with the physical and chemical properties of various aroma materials, consider all aspects comprehensively, in order to obtain a satisfactory formula.


Cosmetics are in direct contact with the skin for a long period of time, so safety is of paramount importance. As the main additive, the safety of fragrance directly affects cosmetics.

The safety of fragrance ingredients is evaluated by a comprehensive program operated by The International Fragrance Association(IFRA).

This program, which has been in operation since 1973, includes a code of practice that provides advice and guidance on good manufacturing practices for the safety assessment of fragrance ingredients, including safety standards that restrict or prohibit the use of certain fragrances. Learn more.

IFRA also requires the following six testing to be done for each fragrance material:

  • Acute oral toxicity test
  • Acute dermal toxicity test
  • Skin irritation test
  • Eye irritation test
  • Skin contact allergy test
  • Photosensitivity poisoning and skin photosensitization test

Even then, due to differences between people, there can be significant differences in allergic or irritant reactions to certain fragrances, which should be collected, studied, and avoided timely.

For the purposes of product label disclosures, fragrance ingredients or mixtures added to products are often referred to by the term perfume or fragrance. There are hardly any fragrances specified for the composition of the material, as this information is highly protected and proprietary. However, the lack of disclosure means that consumers are not fully aware of all the ingredients in a product, which may be of concern to some users.
For this reason, the EU has listed 26 of the most common perfume allergens whose names must appear on product labels when their levels exceed a certain level.

How to choose your fragrance

Choosing a fragrance for your cosmetics can be a daunting task because, with so many scents to choose from, even the same fragrance may have different notes.

As a supplier, we believe that your fragrance should be considered in the following ways:

  • Know your target audiences, such as age, gender, and people of different age groups who have different preferences.
  • Define the positioning of your product, each product has its own range of applicable scents.
  • Know the allergens in the fragrance, it is best to be allergen free if conditions allow. If not, it is important to know exactly which allergen is present and its harmful effects.
  • If the price allows, try to use natural ingredients, which are undoubtedly the most popular.

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