Essential Oils and Carrier Oils, What's the difference?

Essential Oils and Carrier Oils are not the same and should not be used interchangeably. They are two different types of substances that are not the same.

Carrier Oils
Also known as base oils, vegetable oils or fixed oils. Essential Oils and absolutes are usually diluted into carrier oils.

Carrier oils earn this name due to the fact that they "carry" additives, such as Essential Oils into the skin. They do not evaporate and is why Carrier oils are also called Fixed oils.

They can go rancid through oxidation.

Carrier Oils are true oils derived fromm plant and animal fats. The main constituents in carrier oils are fatty acids (lipids), waxes, and water-soluble vitamins (A, D, E and K). Carrier oils are obtained using (see extraction methods blog) expeller pressed (hot or cold pressed), solvent extraction, maceration/infusion, centrifuge, CO2 extraction, supercritical carbon dioxide extraction or boiling.

Uses: Massage therapy, soap-making, lotion-making, lip balm, hair care products, skin care products, straight out of the container, the list goes on.

Essential Oils
Defined as concentrated volatile natural aromatic compound of a plant. Basically it is an "oily-like", hydrophobic, aromatic essences from plant material (roots, stem, leaves, flowers, bark, seeds, berries, peels, and resin). The main chemical make-up of Essential Oils are: alcohols, aldehydes, esters, ethers, ketones, phenols, terpenes and oxides. Essential oils are usually extracted using steam distillation under pressure, except for citrus oils which are extracted by cold pressing. Essential oils can also be extracted with water distillation (plant material is completely immersed in water and then is boiled, then condensed and cooled down. The oil is then separated out, as it layers on the top of the water, leaving floral waters, which are also called hydrosol or sweet water). Any other method of extraction, like CO2 extraction is labeled an extract (however, there are some Essential oils that can not be extracted with distillation or expression).

Essential oils are also known as volatiles, aetherolea or ethereal oils.

Essential oils can evaporate (volatile), are fat-soluble and do not go rancid, however they can lose their potency through oxidation.

Essential oils are not true oils because they do not contain fatty acids (lipids). They have to be diluted with a Carrier oil due to skin irritation if used at full potency.

Uses: Inhalation for aromatherapy, natural fragrance, added to massage oils, skin care products, burned or diffusion into the air.

What are Essential Oils that have been extracted by means other than being cold pressed or steam distilled? These are called extracts, which itself has several subcategories.

Extracts

Extracts are Essential oils dissolved in alcohol or Essential oils extracted utilizing a solvent. Extracts can evaporate like Essential oils.

Extracts are extracted by means of expression (cold or hot pressed), absorption (steeping in alcohol, water or glycerin), maceration, distillation with maceration, solvent extraction and florasol extraction (uses benign gaseous solvents at or below ambient temperatures, decreases thermal degradation of the product). Extracts can have an advantage over Essential Oils due to the fact that they are least likely to have been damaged by heat.

Extracts have several subcategories: Hydrosols, infusions, tinctures, glycerites, oleoresin, concretes and absolutes.

Hydrosols are the aromatic water that is left behind during the production of essential oils. These are also called floral waters or sweet water.
Infusions are plant material steeped in water over time, oil infusions are steeped from days to weeks.
Tinctures are plant material steeped in alcohol solution.
Glycerites are extracts in glycerine.
Oleoresins are formed when an alcohol based extract has the alcohol evaporated from it.
Concretes are formed when plant material are steeped in a solvent (hexane), then distilled to remove the solvent, leaving behind what is called a concrete.
Absolutes are when a concrete is mixed with and alcohol to extract the aromatic compounds, then the alcohol is evaporated out. This is more concentrated than Essential oils.
There are also chemically-created essences that are called extracts, but are created in a lab.

Uses: Cooking, perfumes, medicine, ...etc.

When shopping, look at your INCI names, ask your supplier questions if you are not sure and ask how the item is extracted. Look at the Certificate of Analysis or Material Safety Data Sheets for more information, if available. You can see what was added to the product in question. Hopefully, your supplier will have it posted in an easy to find place.

Shop for Carrier Oils at www.earthly-oils.com

A little about labeling.

I know this post is short, here are some links about labeling your products if you live in the USA, Europe and Canada. Click this link: Cosmetic Labeling Guide, if you plan on selling cosmetics in the United states.

The European Union's Cosmetic Directive (European Union Policies) has its own rules for companies residing in one of the 38 European member states.

For our northern neighbors in Canada, look at the Health Canada's website for rules on labeling there (Health Canada cosmetic labeling).

Is my product a cosmetic or a drug?

Want to violate the law? Market your product that is a cosmetic as a drug or market a drug as a cosmetic. First, we need to determine if a product is a drug or a cosmetic, there are laws and regulations determined by a product’s intended use.

Federal Food, Drug and Act’s definition of a cosmetic?

“Articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body… for cleansing, beautifying, promoting attractiveness, or altering the appearance” [FD&C Act, sec. 201(i)]. They even provide us with examples of products included within the definition as skin moisturizers, perfumes, lipsticks, fingernail polishes, eye and facial makeup preparations, cleansing shampoos, permanent waves, hair colors, and deodorants, as well as any substance intended for use as a component of a cosmetic product.

Federal Food, Drug and Act’s definition of a drug?

“Articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease” and  “articles (other than food) intended to affect the structure or any function of the body of man or other animals” [FD&C Act, sec. 201(g)(1)].

So… what if it is both a cosmetic and a drug?

A perfect example of a product that meets the criteria for being both a cosmetic and a drug is anti-dandruff shampoo.  Also products marketed as a sunscreen and antiperspirants are considered both. Keep in mind that the FDA does not recognize the term “cosmeceutical.”

Be careful of product claims, if it is stated that your product can treat and/or prevent disease or the product affects the structure of functions of the human body… it is a drug. Examples of this are, skin lightening or cellulite reduction claims. If you are making claims that your product is a treatment, prevents or cures diseases or other ailments…it is a drug. So do not place those claims on your product label, advertise the claims on the internet, television or other promotional items. Now if you want to make those claims, just follow the rules and guidelines set forth by the FDA.

Earthly Oils sells carrier (base) oils, for the most part, these oils are for cosmetic purposes. Some are used by massage therapists as lubricants, this places our products within the cosmetic category. However, if the oil/butter is said to relieve joint pain or it is for other therapeutic purposes, we would have to sell them as drugs and follow the FDA's guidelines and labeling protocol.

Does my product require FDA approval?

Cosmetic products and ingredients do not require FDA approval before being placed on the market (does not include color additives). If your product is considered a drug, it needs premarket approval by the FDA through the New Drug Application (NDA) process, after a drug category is determined; it goes through the FDA’s Over-the-Counter (OTC) Drug Review.

Do I have to register my product?

Well it depends. If you are selling a drug, then the answer is definitely “yes.” For cosmetics, there is a program that is maintained by the FDA called the Voluntary Cosmetic Registration Program. This program is voluntary for cosmetic establishments and formulations. The FDA does not require cosmetic establishments or product formulations to be registered.



Labeling a combination drug and cosmetic product.



 

Labeling a product that is both a drug and cosmetic?

Combination drug/cosmetic products must have labeling that reflects the nature of its combo status. Drug ingredients are listed as “Active ingredients” (listed in order alphabetically) and cosmetic ingredients are listed as “Inactive ingredients” (listed with the most predominant ingredients in descending order) on the label.

Well, what category is soap in?

It is a cosmetic according to the FD&C Act section 201(i)(1) because it is used for cleansing. But FD&C Act section 201(i)(2) excludes it from being defined as a cosmetic. The FDA does not regulate soap. It is regulated by the Consumer Product Safety Commission. 

The FDA interprets soap as:

-          “the bulk of the nonvolatile matter in the product consist of an alkali salt of fatty acids and the product’s detergent properties are due to the alkali-fatty acid compounds, and

-          the product is labeled, sold, and represented solely as soap.”

Is my cleanser regulated by the FDA?

Well, if the product consists of detergents or primarily of alkali salts of fatty acids and is intended not only for cleansing but also for cosmetic uses (deodorant, or skin moisturizer); it is to be regulated as a cosmetic.

If  the product consists of detergents, or primarily of alkali salts of fatty acids, and is intended not only for cleansing but also to cure, treat, or prevent disease, or to affect the structure of any function of the human body: it is regulated as a drug (antibacterial cleanser that treat acne), or both a drug and cosmetic.

If a product is intended solely for cleansing the human body, has the characteristics consumers generally associate with soap, and does not consist primarily of alkali salts of fatty acids; these may be labeled as a soap but have to be regulated as a cosmetic.

Check out the FDA's section on cosmetics for more information; http://www.fda.gov/Cosmetics/default.htm

Let's learn more about labeling in my next post.
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The Name Game

THE INCI NAME GAME

So first of all... what is the INCI name of a product? Well the Personal Care Products Council (which has been around since 1894 and undergone numerous name changes) describes the INCI (International Nomenclature of Cosmetic Ingredients) as names used in the United States, the European Union, Japan, and many other countries, for listing ingredients on cosmetic product labels. There is this VERY expensive dictionary, if you are interested, called the "Council's International Cosmetic Ingredient Dictionary and Handbook. It is translated into many languages for individuals to be able to label INCI names in their national language. All INCI names are assigned by this committee, the International Nomenclature Committee to be exact.

INCI name is a reliable way when you shop from several different suppliers, to find a specific ingredient. Suppliers like to brand themselves, so they may change an emulsifier's name to suit their brand. So one type of emulsifier can have several brand names. Think of an INCI name as a generic name for cosmetic ingredients.

The INCI name also helps to understand what ingredients are in a product. One can determine if their avocado butter is blended with other butters and oils to make it more solid or if it has been hydrogenated to make it more solid.

The INCI doesn't help with trade secrets, one product may be a blend, but we may not know the percentage of each ingredient. Some suppliers or manufacturers may be kind enough to tell us a percentage of certain ingredients on their label, while others may not.

INCI names are those alien-looking hard to pronounce words that we see on cosmetic ingredients, usually Latin and English words. Some manufacturers are nice enough to put the INCI name and then the actual product name in parenthesis, for example, Vitellaria Nilotica (East African Shea) butter. Just keep in mind that they are only obligated to place the INCI name on the label.

Also, shopping in many markets in other countries, there are many spellings for one word, that is another reason to know the INCI name for the ingredients you are searching for everywhere.

There is a hidden issue with INCI names, some names may have been changed and some even have synonyms. For instance, Shea butter (from West Africa) used to be called, Butyrospermum Parkii. Now it is know as Vitellaria paradoxa. East African Shea is known by the INCI name of Vitellaria Nilotica. Phulwara butter has a multitude of synonyms not only with the INCI name but also with the common name. I have found a total of four different INCI names for Phulwara butter, Aisandra butyracea, Diploknema butyracea, Bassia butyracea, and Madhuca butyracea. Granted, I believe some of these are from different trees from the same family, kind of like East and West African Shea butter. As for the multiple common names for Phulwara butter, I also believe it depends on the region from which it is harvested.

So keep in mind, if you are selling products, especially in the USA, they must be properly labeled.
You should know your INCI names.

So catch me at my next blog about more FDA guidelines.

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Oil extraction methods

So... how do you get the oil out of the plant? There are several types of processes to remove oil from plants. In the future I will even review oils from animals, plants and even eggs. This describes  extraction of Carrier Oils.

Filtering:

This is done to remove sediment particles, it removes a negligible amount of flavor and antioxidants (about 5%). It makes a product more visually appealing.

Boiling:

This method is used mostly to remove animal fats, like lard.

Cold Pressed/Cold Expeller Pressed:
The seeds/nuts and/or fruit pulp are crushed then mechanically pressed. The temperature should not exceed 120^oF which is cause by friction from the pressing. This method produces less oil, but the oil is of a higher quality. Generally oils produced by this method only require to be filtered once to remove particles (shell pieces or fruit fibers).

Hot Pressed:

Seeds/nuts and fruit pulp are crushed and heated, then the oil is pressed out. This process does produce a large amount of oil than cold pressed. The raw material left behind can be pressed again to obtain more oil. The material is heat to approximately 140^oF or more. This method can produce impurities and usually requires the oil to be filtered.

Expeller Pressed:
Expeller pressed oils are mechanically pressed from seeds/nuts and/or fruit pulp at high pressure to obtain maximum yield. The oil is collected and later filtered. High pressure extraction can cause temperatures to rise above 120 degrees. Only if temperature is monitored and kept under 120 degrees, can the oil be called cold pressed. Otherwise it is simply called expeller pressed.

Solvent Extracted:
Sometimes it is necessary to use a solvent in order to extract the oil from certain seeds, nuts or kernels in order to make the extraction cost effective. Hexane is usually the solvent of choice. The nuts/seeds are extracted using hexane or similar chemicals typically yield a much higher return rate. The compound causes most organic materials to quickly break down, which boosts yields well into the 90%. Once the oil has been obtained, the solvent is then removed from the oil (and used again), but a trace percentage of the solvent may still be present in the final oil.

CO₂ Extracted/Supercritical Carbon Dioxide Extraction:
The raw material is finely ground, then the oils is extracted using fluid carbon dioxide as the solvent. Carbon dioxide is converted to liquid using high pressure making it a safe and effective solvent that allows all the desirable active constituents of a plant to be collected without the risk of heat degradation. Once the extraction is complete, the pressure is released allowing the carbon dioxide to return to its natural gaseous state, leaving behind only the extracted essence of the plant. CO₂ extracted oils are the closest representation of the natural plant ever.  The chemical composition may have different therapeutic and safety properties than oils extracted by other methods. CO₂ total extracts include the volatile components as well as the heavier, waxy components that give plants their color, and are therefore thick and waxy in consistency.

Infusion/Macerate:
An infused or macerated oil is a vegetable oil that has been "infused" with the fat soluble properties of other botanicals or a base oil. Dried or fresh plant material is macerated by being steeped in a Vegetable Oil and agitated (shaken vigorously) daily for anything from several days to 6 weeks. Botanical material is then removed by filtering the Oil, leaving the Oil with some of the therapeutic properties of the botanical material. The base oil is sometimes gently heated to encourage infusion.  The final oil is then well filtered to remove any traces of plant particles. The benefit to using an infused vegetable oil is that the infused oil will contain the therapeutic properties of both the vegetable oil and the botanicals that were infused into the oil.

Refined, Bleached and Deodorized (RBD):

When ordering oils, you may see RBD listed next to its name or in conjunction with its extraction method. The terms listed below explain this process.

Refined:

Some oils undergo a refinement process in order to remove impurities, improve the color or texture, or stabilize the shelf life of the oil. The oil is reacted with a sodium hydroxide solution to saponify the free fatty acids into soap (which sink to the bottom). Phosphorus may be added to remove mucilage and wax. The oil is then filtered or centrifuged and washed with water until the pure oil remains. The oil may also be degummed to remove the sticky phospholipids, color pigments and odor lending portions.

Bleached:
Some oils are bleached in order to improve the color and clarity of the oil. Bleaching is generally done by passing the oil through fuller's earth, active charcoal, or clay and then filtering the oil to remove the filtrates.

Deodorized:

Deodorization process is used to remove compounds that lend an unappealing or overpowering aroma or taste in an oil. This is generally done by blowing high temperature steam through the oil to vaporize the aromatic components. This process is made more effective by heating the oil to high temperatures and performing this process under a vacuum to help remove all of the odorous substances. Due to the high temperatures used, deodorization is clearly the most damaging process of refinement

EDIT: Here is information from another website that perfectly describes extraction methods for Essential oils. www.aromaworld4u.com a great website for people interested in aromatherapy and essential oils. Here is a repost from their website on essential oil extraction:

Essential Oil Extraction Methods

The term "essential oil" is generally applied to all aromatic products such as essence oils, absolutes, resinoids, and concretes. To get essential oils the aromatic essence molecules of the plant must be captured by technical extraction methods. Essential oils are liquids stored in various places in plants, that can be removed from the plant using extraction methods such as steam distillation, cold pressing, chemicals, or fat-absorption.

Essential oils can be extracted using a variety of methods as mentioned above, although some are not commonly used today. Presently, the most popular method for extraction is steam distillation and the majority of essential oils used in aromatherapy are distilled in this way, but as technology is advancing, more efficient and economical methods are being developed.

The extraction of an oil require large quantity of plant material and the method used to extract the oil is time consuming and requires a high degree of skill and care. Hence, pure essential oils are expensive, but they are also highly effective - only a few drops at a time are required to achieve the desired effect.

Essential oils are usually liquid, but can also be solid, like orris root or semi-solid according to temperature, like the rose. They dissolve in pure alcohol, fats and oils but not in water.

Some of the important methods of extraction are discussed below :

Distillation

In this, water is heated to produce water vapor, which carries the volatile chemical of the aromatic material with it. The water vapor is then condensed using a condenser and the resulting distillate is collected. The essential oil will normally float on top of the hydrosol (the distilled water component) and is separated out.

Water Distillation  In water distillation, the botanical material is completely immersed in water and then is boiled. This method protects the oil to be extracted to a certain degree since surrounding water prevents it from overheating.

Then it is condensed and cooled down. The oil is then separated out, as it layers on the top of the water. The water separated out in this process is termed as floral waters (also called hydrosol or sweet water) such as rose water, orange water and lavender water.

Water distillation can be operated at low pressures to reduce boiling temperature. This helps in protecting the botanical material and essential oil as well.

This method is used for extraction of oils that are sensitive to heat.

If a lot of exposure to hot water is not mentioned for a particular plant such as lavender, it is best to find an extraction method better suited.

Any botanical material that contains high amounts of esters do not take well to this extraction method, since the exposure to hot water will break down the esters into alcohols and carboxylic acids.

Steam Distillation Steam distillation is the most common method of extracting essential oils. Steam distillation is done in a still (The still is tall with a head and a well-insulated swan's neck preceded by a mechanism to prevent fumes and impurities passing through). Fresh, or sometimes dried, botanical material is placed in a closed container of the still, and pressurized steam is generated which enters the container and circulates through the plant material. The heat of the steam forces the intercellular pockets that hold the essential oils to open and release them. The temperature of the steam should not be very high as it can damage the botanical material but should be high enough to open the pockets which hold the essential oil.

Tiny droplets of essential oil evaporate and attach to the steam. The steam which then contains the essential oil, is passed through a cooling system to condense the steam, which forms a liquid from which the essential oil and water is then separated by decantation. The oil forms a layer on the water surface as it does not dissolves in water and hence is separated easily.

This method is not used for extraction of oils that are sensitive to heat

Hydro Diffusion Hydro Diffusion method for extraction of oils is a type of steam distillation and is only different in the way in which steam is enters the container of the still. In hydro diffusion, steam is fed in from the top onto the botanical material while in the case of steam distillation, steam is fed from the bottom. In this way the steam can saturate the plants more evenly and in less time than with steam distillation.

The condensation of the oil containing steam mixture occurs below the area in which the botanical material is held. The main advantage of this method over steam distillation is that less steam is used hence shorter processing time and therefore a higher oil yield. This method is also less harsh on the botanical material.

Fractional Distillation When we say fractional distillation, it only refers to normal distillation process. In this only difference is that the oil is not collected continuously, but is collected in parts i.e. fractions and oil normally so extracted is Ylang-Ylang oil.

Rectification When an essential oil contains any impurities, it can be purified by re-distillation, either in steam or in vacuum and this purification of oil by re-distillation is referred to as rectification.

This process is used to make oils of standard quality. An example of rectification is eucalyptus oil.

Cohobation: In some essential oil extractions, some chemical or part of the essential oil gets dissolved in water and therefore gets removed from the oil. So to get the whole oil, we add the deficient chemical to the deficient oil and re-distillation is done until we get the complete oil. An example of this is rose oil.
 
Expression
This method is used to extract citrus essential oils. It is basically a cold pressed method of extraction.

Sponge Expression Most citrus essences are extracted by means of expression, and in the past were done by hand where the fruit pulp was removed, with the rind and pith then soaked in warm water to make the rind more pliable, since the pith of the fruit absorbed the water.

After the fruit has absorbed the water and become more elastic, it was inverted which helped to rupture the oil cells and a sponge placed next to the rind. It was then squeezed to release the volatile oil, which was then collected directly into the sponge.

As soon as the sponge became saturated with oil, it was squeezed and the essential oil collected in a vessel and then decanted.

Cold-pressed Expression  Another expression method of extracting essential oils is coldpressed expression, or scarification method. It is used to obtain citrus fruit oils such as bergamot, grapefruit, lemon, lime, mandarin, orange, and tangerine oils. In this process, fruit rolls over a trough with sharp projections that penetrate the peel. This pierces the tiny pouches containing the essential oil. Then the whole fruit is pressed to squeeze the juice from the pulp and to release the essential oil from the pouches. The essential oil rises to the surface of the juice and is separated from the juice by centrifugation.

It is important to note that oils extracted using this method have a relatively short shelf life, so make or purchase only what you will be using within the next six months.

Although many citrus oils are also produced by steam distillation, they seem to lack the vibrancy of the cold pressed oils.

Machine Abrasion Machine Abrasion is very much same as cold-pressed expression method and is mainly used in extraction of citrus essential oils.

In machine abrasion, a machine strips off the outer peel of the botanical material, which is then removed by running water and left over is then fed into a centrifugal separator.

The centrifugal separation is done extremely fast. But, it should be noted that due to the fact that the essential oil is combined with other cell content for some time, some alteration could occur in the oil due to enzymatic action.

Solvent Extraction

In this extraction method, solvents are used to extract the essential oils from the botanical material.

Solvent Very delicate aromatics, Jasmine, Linden Blossom, etc. can not survive the process of distillation. To capture their magical aromas, a process of solvent extraction is used.

A hydrocarbon solvent (usually hexane) is added to the botanical material to help dissolve the extractable matter from the botanical material which includes non-aromatic waxes, pigments and highly volatile aromatic molecules. When this solution is filtered and then the filtrate is subjected to distillation at low pressure, a substance containing resin (resinoid), or a combination of wax and essential oil (known as concrete) is left.

The concrete is further processed to remove the waxy materials which dilute the pure essential oil. To prepare the absolute from the concrete, the waxy concrete is warmed and stirred with alcohol (usually ethanol). When we heat and stir the concrete, it breaks up into minute globules, and separation takes place as aromatic oil is more soluble in alcohol than that in wax. But along with the aromatic molecules a certain amount of wax is also dissolved and this can be removed only by agitating and freezing the solution at very low temperatures (around minus 35 degree celsius). In this way most of the wax precipitates out. As a final precaution the purified solution is cold filtered leaving only the wax-free material (the absolute) i.e. the essential oil.

This solvent extraction actually yields three usable products; first the concrete (as in rose concrete, my favorite solid perfume), the precious absolutes i.e. the oils, and the floral waxes, for addition to candles, thickening creams and lotions as a softly floral scented alternative to beeswax.

Although more cost-efficient than enfleurage, solvent extraction is more expensive than steam distillation so it is reserved for costly oils which cannot be distilled.

This is not considered the best method for extraction of essential oils, as the solvents can leave a residue behind which could cause allergies and effect the immune system, but it's great for making resins for this very reason.

Maceration Maceration actually creates more of an "infused oil" rather than an "essential oil" and is most often used for creating extracts and resins.

The botanical material is soaked in vegetable oil, water, or another solvent. If it's soaked in vegetable oil, and then heated and strained, it can be used for massage and if soaked in water or another solvent such as alcohol, will create a much thicker extract or resin.

Enfleurage Enfleurage is a very labour-intensive way of extraction and an expensive process. Therefore it is rarely used today. In some cases where flowers, such as jasmine or tuberose, have very low contents of essential oil and are extremely delicate, heating them would destroy them before releasing the essential oils, enfleurage is used to remove the essential oils.

Flower petals are placed on solid sheets of warm fat, which will absorb the essential oil from the flowers. When all the fragrance is transferred from the flowers to the fat they are removed and replaced with fresh ones. This process is repeated several times until the fat becomes saturated with the essential oil.

A solvent, usually alcohol, is then added to the saturated fat which separates the essential oil from the fat. The remaining fat is then used to make soaps.

Enfleurage has the advantage that even the most delicate components of the flower oils are preserved

Hypercritical Carbon Dioxide (CO2) The use of hypercritical carbon dioxide extraction is a fairly new way to extract essential oils from botanical material and although a bit on the expensive side, does yield good quality oils.

Carbon dioxide becomes hypercritical at 33 degrees celsius, which is a state in which it is not really gas or liquid, but has qualities of both, and is an excellent solvent to use in the extraction of essential oils since low temperature is required and the fact that the process is near to instantaneous.

The carbon dioxide is inert and therefore does not chemically react with the essence that is being extracted and hence, essential oils can be extracted in a similar way as other solvent extraction methods. To remove the carbon dioxide solvent, you simply need to remove the pressure applied. This process has to take place in a closed chamber since the hypercritical pressure required for carbon dioxide is 200 atmospheres. To achieve this pressure a specific equipment is required which is very expensive.

The advantage of this method, of course, is that no solvent residue remains, since at normal pressure and temperature, the carbon dioxide simply reverts to a gas and evaporates. Hypercritical carbon dioxide extraction has given us essences of some aromatics that don't yield essential oils, for example Rose Hip Seed and Calendula.

Many carbon dioxide extractions have fresher, cleaner, and crisper aromas than steam-distilled essential oils, and they smell more similar to the living plants. Scientific studies show that carbon dioxide extraction produces essential oils that are very potent and have great therapeutic benefits.

Florasol/Phytol This extraction method uses a new type of benign gaseous solvents. The unique properties of these solvents are used for the extraction of aromatic oils and biologically active components from botanical materials. Florasol is the solvent upon which the process is based.

Extraction occurs at or below ambient temperatures, hence there is no thermal degradation of the products. The extraction process utilizes the selectivity of the solvent and produces a free flowing clear oil free of waxes.

  

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Fatty acid profiles

From the previous post, we learned what makes some oils liquid, soft, and solid. Now what are the properties of specific fatty acids? If you are a soap-maker, it is important to know the properties fatty acids will provide the soap being produced.


The composition of the fatty acid helps to determine its melting point, stability and its saponification value.

When choosing oils for your lotions, massage oils and other handmade products, it is important to know the properties of the chosen oil. Knowing the fatty acid content is very important for soap-making.

Saturated fatty acids tend to have good cleaning properties and make a nice foamy lather. The longer the fatty acid chain, the harder bar of soap it will make. The shorter the chain, the harsher the soap will be but great at breaking down oily substances. To much of the shorter chained fatty acids can make a brittle bar of soap.

Unsaturated fatty acids have good cleaning properties but lather poorly. Unsaturated fatty acids do make a milder bar of soap. These fatty acids work best on dirt, they are not that great at breaking down oily substances.

MAIN SOAP-MAKING FATTY ACIDS

Lauric: A saturated fatty acid. Makes a hard bar of soap and makes a fluffy lather. Try not to add to much, it can cause excessive drying and can be harsh. Lauric acid is a main component of coconut oil and palm kernel oil (about 50% for both oils).

Linoleic: A polyunsaturated fatty acid. Best if used in small amounts with more stable oils, it has a short shelf-life (approximately six months). Makes a mild soap, provides conditioning and moisturizing properties to soap. Linoleic is an essential fatty acid and is necessary for good health. Deficiencies of this fatty acid can cause the skin to become dry and scaly, hair loss can also occur. Linoleic can also help combat acne. It is a main component of safflower oil (60%) and sunflower oil (65%).

Linolenic: A polyunsaturated fatty acid with three double bonds. It has a high chance of becoming rancid. Also helps to provide conditioning properties to soap. Helps inhibit inflammation from burns.

Myristic: A saturated fatty acid that makes a hard bar of soap with a good lather. Great cleaning properties but can be harsh and drying. Found in nutmeg butter, coconut oil and palm kernel oil.

Oleic: A monosaturated fatty acid that adds conditioning and moisturizing properties to soap. However, it does not produce a good lather. This fatty acid is a main component of olive oil (60 -70%). Helps increase the absorption rate of active agent ands spreads well on the skin.

Palmitic: A saturated fatty acid that has a long shelf-life. It can be harsh and makes a hard bar of soap with a creamy, stable lather. Palmitic acid is a skin barrier component, when combined with ceramides and cholesterol, it protects the skin. High concentrations are found in avocado and wheat germ oil.

Ricinoleic: A monounsaturated fatty acid that provides conditioning properties, has a creamy, fluffy and stable lather. This fatty acid is a main component in Castor oil.

Stearic: A saturated fatty acid that makes a stable, creamy lather and makes a hard bar of soap. It has a long shelf-life. Stearic acid is a skin barrier component that provides skin protection. It helps with moisture retention and skin flexibility. Found in shea and cocoa butter.

Palmitoleic: A monounsaturated fatty acid. Found in macadamia nuts, sea buckthorn oil and avocados. A natural fatty acid component found in the skin.

Check out the next blog, how are oils extracted?

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The greasy basics

Every wonder why some oils are thick, thin, buttery soft or hard as a rock? Want to know the science to why some oils/butters have a long shelf-life? Do you fancy chemistry? Particularly Organic chemistry? You are in the right place. I am going to pretty much explain this as easily as possible. If you want to formulate and not care about the nitty gritty, tune into future posts that are not so scientifically oriented. We will add an oil, butter and/or wax every three to four days, so check us out.

Triglycerides have a glycerol back bone and three fatty acid chains.  Saturated fatty acid chains have no double bonds, a fatty acid chain with double bonds are called unsaturated, chains with a single double bond are called monounsaturated, and a chain with greater than one double bond is called polyunsaturated, are you still with me? The image above is unlikely but a perfect example of a triglyceride, a triglyceride usually does not have three identical chains.

Those chains with a single bond (saturated) are least likely to oxidize because those bonds are harder to break. Expect saturated fats to be able to hang around longer before they become rancid. Fatty acids with double bonds are not very stable and go rancid more quickly, especially those with polyunsaturated chains. Utilizing lipid numbers, you can tell how many bonds there are in a fatty acid. Ex. C18 (stearic acid), C18:1 (oleic acid), C18:2 (linoleic acid) and/or C18:3 (alpha-linolenic acid). These are lipid numbers. The letter C is the carbon atom, the number after the letter C represents the number of carbon atoms within the fatty acid and the final number after the colon is how many double bonds within the fatty acid chain.

HYDROGENATION

So fatty acid chains with double bonds can be broken and tend to react with oxygen causing oxidation. Some manufacturers hydrogenate oils by breaking the double bond and placing hydrogen into those open sections. They basically have created a saturated chain. I haven't seen much research on hydrogenated oils in skin care, but have heard a lot about why we shouldn't eat hydrogenated oils. The plus side to hydrogenated oils is that they are now going to have a longer shelf-life and becoming rancid early has been decreased, plus they look more like a butter.

So why are some oils solid and some liquid? It is all in the shape of the fatty acids. Saturated fats pack in nicely together because they form a straight line. So they tend to be more solid. When the fatty acid has a double bond, it forms a bit of a kink, and in some cases, a bend. Those double bonds can't play close together and oils with these bonds tend to be more liquid at room temperature. See pic below.

DOUBLE BOND TERMINOLOGY

So, have you been seeing Cis- or trans- ? This terminology is seen when describing the double bond on a fatty acid. Cis- is when the hydrogen atoms at the double bond occur on the same side of the bond. These chains have a bend at the double bond. These also tend to be more liquid and have a shorter shelf-life.

Trans- has the hydrogen atoms on opposite sides of where the double bond occurs. These chains tend to be straighter. The lay nicely together and make a thicker product that has a longer shelf-life.  Trans- in a sense, behave more like they are saturated fatty acids.

Partial hydrogenation basically turns a "cis-" bond into a "trans" bond using a chemical process. Trans- fats are rarely a natural occurance.



As a home crafter, if you know the properties of oils and butters you plan on using in formulating recipes, you can figure out if the final product will have a short or long shelf-life. No double bonds makes a butter (long shelf-life), many double bonds and light oil (shorter shelf-life), few double bonds makes a heavy oil (longer shelf-life than lighter oils).

Look for my next blog,  I will discuss the fatty acids commonly utilized in the soap-making process.

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