Dry shampoo otherwise known as hybrid shampoo is a type of
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the ...
which reduces
hair greasiness without the need for water. It is in powder form and is typically administered from an
aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be natural or Human impact on the environment, anthropogenic. Examples of natural aerosols are fog o ...
can. Dry shampoo is often based on
corn starch
Corn starch, maize starch, or cornflour (British English) is the starch derived from corn (maize) grain. The starch is obtained from the endosperm of the kernel. Corn starch is a common food ingredient, often used to thicken sauces or sou ...
or rice starch. In addition to cleansing hair, it can also be used as a tool for hair-styling as it can create volume, help tease hair, keep
bobby pin
A bobby pin (also known as a kirby grip or hair grip in the United Kingdom) is a type of hairpin, usually of metal or plastic, used in coiffure to hold hair in place. It is a small double-pronged hair pin or clip that slides into hair with the pr ...
s in place, and be used in place of
mousse
A mousse (; ; "foam") is a soft prepared food that incorporates air bubbles to give it a light and airy texture. Depending on preparation techniques, it can range from light and fluffy to creamy and thick. A mousse may be sweet or savory. as e ...
in wet hair. Dry shampoo proponents attest that daily wash-and-rinse with detergent shampoo can strip away natural oils from hair. However, others attest that spraying dry shampoo every day will lead to a build-up of product that can dull hair color and irritate the scalp, arguing that the scalp needs regular cleansing and
exfoliating to get rid of
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
, remove dead skin cells, and stay healthy.
The powders within dry shampoo are meant to absorb the
sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...
in hair, which is excreted from
sebaceous glands
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number ...
and can give hair a greasy appearance when the oil is overproduced. By absorbing the oils, the greasy appearance of the hair is improved; however, the absorbed oils and powders remain in the scalp, so the hair may appear clean but feel unclean to the user. The user may need to wash their hair with traditional
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the ...
s to formally remove the oils and dry shampoo powder in order for the scalp and hair to feel and appear clean.
History
Throughout history, people have used powder-based products similar to dry shampoo to cleanse and improve the appearance of hair. Evidence suggests that people in Asia used clay powder to clean their hair as early as the late 15th century. During the
Elizabethan era, a lack of regular bathing made clay powders popular among women to cleanse their hair of excess dirt and oil. Some powders were even colored for decorative purposes. Powders were also used by 18th-century British and American elites to absorb the oils in hair and wigs at a time when long hair was a marker of masculine privilege. The first written reference of dry shampoo in the United States is from the late 1700s, when starches were used to deodorize and alter the color of wigs. Other early mentions of dry shampoo include foam substances used by barbers to clean hair in the late 1800s.
The first commercially produced dry shampoo was sold in the 1940s, but the product existed before that. By the early 1940s, the Stephanie Brooke Company of Jersey City, New Jersey had developed Minipoo, the first brand of commercially produced dry shampoo powder. Minipoo was marketed to women and children for use in scenarios such as "surprise dates" or when they were sick in bed, according to the
Smithsonian's
National Museum of American History
The National Museum of American History: Kenneth E. Behring Center collects, preserves, and displays the heritage of the United States in the areas of social, political, cultural, scientific, and military history. Among the items on display is t ...
. Since 1790, 71 patents have been filed for dry shampoo products in the United States.
Composition
Dry shampoo is generally composed of a carrier agent containing an active powder. Normally,
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...
is used as the active powder. When the powder is sprayed onto hair, the carrier agent evaporates while the starch remains attached. While the active powder can be replaced with other substances such as
activated carbon
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that increase the surface area avail ...
and
alumina, these substances are generally not used due to their inability to biodegrade. In particular, activated carbon and alumina leave behind a residue that is difficult to remove. Presently,
oryza sativa starch and
cetrimonium chloride
Cetrimonium chloride, or cetyltrimethylammonium chloride (CTAC), is a topical antiseptic and surfactant. Long-chain quaternary ammonium surfactants, such as cetyltrimethylammonium chloride (CTAC), are generally combined with long-chain fatty alc ...
are the most common starches used in dry shampoos. Dry shampoo in the form of aerosol also often contains a propellant ingredient.
The propellant used in dry shampoo usually consists of
butane
Butane () or ''n''-butane is an alkane with the formula C4H10. Butane is a gas at room temperature and atmospheric pressure. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature. The name but ...
,
isobutane
Isobutane, also known as ''i''-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colourless, odourless gas.
It is the simplest alkane with a tertiary carbon a ...
, and
propane
Propane () is a three-carbon alkane with the molecular formula . It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used a ...
, which makes up 70–90% of the total composition.
Dry shampoos often contain
anionic surfactants that do not dissolve in water. The surfactant molecules have a hydrophilic portion as well as a hydrophobic portion to bind with water and oils. Surfactants such as detergents rely heavily on micelle formations.
Amphiphile
An amphiphile (from the Greek αμφις amphis, both, and φιλíα philia, love, friendship), or amphipath, is a chemical compound possessing both hydrophilic (''water-loving'', polar) and lipophilic (''fat-loving'') properties. Such a compoun ...
molecules organize into small clusters of micelles with the hydrocarbon non-polar ends facing inwards. When dry shampoo is applied, amphiphile molecules surround suspended oil drops which then can be removed. The anionic substances often leave a form of calcium salts, which are not soluble, in the hair strands that causes hair to be dry and tangled. The alkaline residue may also cause hair and skin irritations.
Types
![Himbawoman](https://upload.wikimedia.org/wikipedia/commons/1/1c/Himbawoman.JPG)
Dry shampoo can be administered as a powder, where all the ingredients of dry shampoo are combined together and applied to the scalp with the hand, or through the aerosol form where the dry shampoo is sprayed directly onto the head. In the aerosol form, the powders comprising the dry shampoo are dispersed throughout pressurized gas inside a can; when the release is pressed, the pressurized gas and powders inside are released, forming the aerosol that lands on the head or scalp.
Homemade dry shampoo
This product has also been made at home, in addition to being purchased in stores.
DIY dry shampoos usually have some sort of starch base, which is one of the key products in commercially produced dry shampoos, and often contains
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
s for scent.
Herbal powder shampoo
Herbal powder shampoos are another form of dry shampoo. As a natural hair-care product, they tend to have fewer negative side effects than traditional mass-market shampoos, and contain a dry powder mixture of
aloe vera
''Aloe vera'' () is a succulent plant species of the genus ''Aloe''. It is widely distributed, and is considered an invasive species in many world regions.
An evergreen perennial, it originates from the Arabian Peninsula, but grows wild in tro ...
and other plant byproducts to reduce skin, eye, and scalp irritation from
surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...
s.
Clay
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
has been used throughout history as a form of dry shampoo. The
Rhassoul
Rhassoul, or ghassoul ( ary, الغاسول, l-ġasul), is a Cosmetics, cosmetic made of natural mineral clay mined from the Atlas Mountains of Morocco. It is mixed with water, sometimes with herbs or other substances, to clean the body. It has b ...
clay, also known as red clay, originating from Morocco is traditionally used as a leave in shampoo and conditioner. Due to its high absorbance of sebum, clay is often used as a remedy for
dandruff
Dandruff is a skin condition that mainly affects the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin, ...
and
seborrhea
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest numbe ...
. Such properties of clay stem from its colloidal particle size and crystalline structure. Even though clay is generally considered to be a natural non-toxic material, it should not be stored in metal containers due to its retention of heavy metals.
For animals
In addition to the liquid shampoos, there are dry shampoos available for pets with fur. The waterless-foaming shampoo is applied directly into the fur of the pet without the need to pre-wet or rinse the pet after application. These shampoos often contain a combination of detergents, antimicrobial agents, and surfactants. Certain conditioners may also contain additional agents such as ''
Melaleuca
''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles or tea-trees (although the last name is also applied to species of '' Leptospermum''). They range in size ...
'' oil for the treatment of fleas. The foaming component of the shampoo comes from a pressurized gas such as carbon dioxide mixing with a foaming liquid. Once the foam is applied to the fur, the foam needs to be worked in vigorously before being wiped off.
Proper application
The product is applied to the scalp or roots of the hair, either through aerosol form or directly applying the powder, the powder within the product is allowed to sit on the hair for an extended period of time, and then the powder is massaged or brushed through the scalp. Allowing the product to sit in the hair before brushing it out allows more time for the product to absorb the sebum oils in the hair and brushing out the product would reduce the powder's potentially noticeable appearance.
* Apply dry shampoo to specific oily areas.
* If using an aerosol dry shampoo, hold the can at least 6 inches away from the application area.
* Once applied, evenly distribute the dry shampoo by either massaging the scalp or brushing through the hair.
* Avoid spraying ends of hair from excessive drying.
* Do not use for more than two days in a row.
Potential side effects
* Cancer
* Hair loss from inflamed
hair follicles
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
due to blockage.
* Respiratory toxicity: Talc is often present in dry shampoos as an absorbent which can lead to respiratory issues.
*
Allergies: There is often the use of fragrances in dry shampoos which may cause allergies or sensitivities.
*
Dermatitis
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can v ...
caused by fragrances and potential metals from dry shampoo.
* Nausea caused by
liquefied petroleum gas
Liquefied petroleum gas (LPG or LP gas) is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, propylene, butylene, isobutane and n-butane.
LPG is used as a fuel gas in heating appliances, cooking e ...
.
* Hormone disruption resulting from the inclusion of
paraben
Parabens are a class of widely used preservatives in cosmetic and pharmaceutical products. Chemically, they are a series of parahydroxybenzoates or esters of parahydroxybenzoic acid (also known as 4-hydroxybenzoic acid). Parabens are effective p ...
s as a preservative.
* Eye irritations should the product accidentally be administered to the eye.
* Fungal growth from the build up of chemical powders and pollutants.
* Breakouts (acne) from the blockage of pores from dry shampoo residues.
* Flammable if the product contains butane, isobutane, or propane in the spray propellant.
References
{{Reflist
Hairdressing
Personal hygiene products
Toiletry
Drug delivery devices