Shampoo Ingredients and How They Work

Shampoo is a hair care product used primarily for the removal of oils, dirt, skin particles, environmental pollution and/or other contaminant particles that gradually build up in hair. The goal is to remove the unwanted build-up without stripping out so much as to make hair unmanageable. Shampoo, when lathered with water, is a surfactant, which, while cleaning the hair and scalp, also acts to remove the natural oils (sebum) which lubricate the hair shaft. Shampooing frequently for some people may be too harsh as these oils are often needed. This is why there are different methods for dry hair and more oily hair. Each person has to use their own regime to maintain the best care for their hair. Usually this comes from practice, until you find what works for you. Often, shampooing is followed by conditioners which increase the ease of combing and styling.

The word shampoo modern English use dates back to 1762, meaning “to massage”. The word was borrowed from from Hindi word champo (imperative of champna), “to smear, knead the muscles, massage”. It itself comes from Sanskrit/Hindi word “champa”, the flowers of the plant Michelia champaca which have traditionally been used to make fragrant hair-oil. Before the creation of shampoos, people typically used soap for personal care in all areas. However, soap had the distinct disadvantages of being irritating to the eyes and incompatible with hard water. This resulted in it leaving a dull-looking film on the hair. In the early 1930s, the first synthetic detergent shampoo was introduced, but not without initial complaints. The 1960s brought the common detergent technology used today, though many companies come up with their own alternatives to make products cleaner, more natural, and more attractive to consumers.

Over the years, many improvements have been made to shampoo formulations. New detergents are less irritating to the eyes and skin and have improved health and environmental qualities. Also, materials technology has advanced, enabling the incorporation of thousands of beneficial ingredients in shampoos, leaving hair feeling cleaner and better conditioned.

Indians have been using different formulations of shampoos using herbs like neem, shikakai or soapnut, henna, bael, brahmi, fenugreek, buttermilk, amla, aloe, and almond combined with aromatic components such as sandalwood, jasmine, turmeric, rosemary, and musk. Rainforests are also a particularly rich source for minerals and scented plants, and are often looked to for new ideas to use in cleansers and bathing products.

How shampoo works?

Shampoo cleans by stripping sebum from the hair. Sebum is an oil secreted by hair follicles that is readily absorbed by the strands of hair, and forms a protective layer. Sebum protects the protein structure of hair from damage, but this protection comes as a cost: it tends to collect dirt, styling products and scalp flakes. Surfactants strip the sebum from the hair shafts and thereby remove the dirt attached to it.

While both soaps and shampoos contain surfactants, soap bonds to oils with such affinity that it removes too much if used on hair. Shampoo uses a different class of surfactants balanced to avoid removing too much oil from the hair. The chemical mechanisms that underlie hair cleansing are similar to that of traditional soap. Undamaged hair has a hydrophobic surface to which skin lipids such as sebum stick, but water is initially repelled. The lipids do not come off easily when the hair is rinsed with plain water. Shampoo applied to wet hair is absorbed into the oil/hair interfaces. The anionic surfactants substantially reduce the interfacial surface tension and allow for the removal of the sebum from the hair shaft. The non-polar oily materials on the hair shaft are solubilised into the surfactant micelle structures of the shampoo and are removed during rinsing. There is also considerable removal through a surfactant and oil “roll up” effect.

New shampoos are initially created by cosmetic chemists in the laboratory. These scientists begin by determining what characteristics the shampoo formula will have. They decide on aesthetic features and consider how thick it should be, what color it will be, and what it will smell like. They also consider performance attributes, such as how well it cleans, what the foam looks like, and how irritating it will be. Consumer testing often helps determine what these characteristics will be. Once the features of the shampoo are identified, a formula is created in the laboratory. These initial batches are made using various ingredients. In the personal care industry, nearly all of the ingredients that can be used are classified by the Cosmetic, Toiletry, and Fragrance Association (CTFA) in the governmentally approved collection known as the International Nomenclature of Cosmetic Ingredients (INCI). The more important ingredients in shampoo formulations are water, detergents, foam boosters, thickeners, conditioning agents, preservatives, modifiers, and special additives.

Ingredients

Water

The primary ingredient in all shampoos is water, typically making up about 70-80% of the entire formula. Deionized water, which is specially treated to remove various particles and ions, is used in shampoos. The source of the water can be underground wells, lakes, or rivers.

Detergents

The second most abundant ingredients in shampoos are the primary detergents. These materials, also known as surfactants, are the cleansing ingredients in shampoos. Surfactants are surface active ingredients, meaning they can interact with a surface. The chemical nature of a surfactant allows it to surround and trap oily materials from surfaces. One portion of the molecule is oil compatible (soluble) while the other is water soluble. When a shampoo is applied to hair or textiles, the oil soluble portion aligns with the oily materials while the water soluble portion aligns in the water layer. When a number of surfactant molecules line up like this, they form a structure known as a micelle. This micelle has oil trapped in the middle and can be washed away with water, thus giving the shampoo its cleansing power. Surfactants are derived from compounds known as fatty acids. Fatty acids are naturally occurring materials which are found in various plant and animal sources. The materials used most often to make the surfactants used in shampoos are extracted from coconut oil, palm kernel oil, and soy bean oil.

Some common primary detergents used in shampoos are ammonium lauryl sulfate, sodium lauryl sulfate, and sodium lauryl ether sulfate. The reason that these common detergents occur in such an abundance is due to being very cheap for the manafacturer to purchase. Their production is so widely used that you might find them in common household cleansers. Also, SLS is so strong that itis also used to scrub garage floors. Worse, it has been proven to cause cancer in the long run. And the American College of Toxicology says SLS stays in the body up to five days. Other studies show it easily penetrates the skin and enters and maintains residual levels in the heart, liver, the lungs, and the brain.

Propylene Glycol (PG, Polyethylene Glycol (PEG), and Ethylene Glycol (EG) are all petroleum derivatives that act as solvents, surfactants, and wetting agents. They can easily penetrate the skin, and can weaken protein and cellular structure. In fact, PG penetrates the skin so quickly that the EPA warns factory workers to avoid skin contact, to prevent brain, liver, and kidney abnormalities. PG is present in many stick deodorants, often in heavier concentration than in most industrial applications. This is something that people should really look at. Would you put a chemical that is used in anti-freeze on your head!

Foam boosters

In addition to cleansing surfactants, other types of surfactants are added to shampoos to improve the foaming characteristics of the formulation. These materials, called alkanolamides, help increase the amount of foam and the size of the bubbles. Like primary detergents, they are also derived from fatty acids and have both water soluble and oil soluble characteristics. Typical materials include lauramide DEA or cocamide DEA. DEA and its derivatives are used in personal-care products and some detergents to neutralize acids making them non-irritating. Slow to biodegrade, they react with natural nitrogen oxides and sodium nitrite pollutants in the air to form nitrosamines, a potential carcinogen.

Thickeners

To some extent, the alkanolamides that make shampoos foam also make the formulations thicker. However, other materials are also used to increase the viscosity. For example, methylcellulose, derived from plant cellulose, is included in shampoos to make them thicker. Sodium chloride (salt) also can be used to increase shampoo thickness.

Conditioning agents

Some materials are also added to shampoos to offset the sometimes harsh effect of surfactants on hair and fabrics. Typical conditioning agents include polymers, silicones, and quaternary agents. Each of these compounds deposit on the surface of the hair and improve its feel, softness, and ability to comb, while reducing static charge. Shampoos that specifically feature conditioning as a benefit are often called 2-in-1 shampoos because they clean and condition hair in the same step. Examples of conditioning agents include guar hydroxypropyltrimonium chloride which is a polymer, dimethicone which is a silicone, and quatemium 80, a quatemary agent.

Preservatives

Since shampoos are made from water and organic compounds, contamination from bacteria and other microbes is possible. Preservatives are added to prevent such growth. Two of the most common preservatives used in shampoos are DMDM hydantoin and methylparaben. Many preservatives contain or release formaldehyde which is a carcinogen, neurotoxin, irritant and sensitizer and has been discovered to cause breast cancer.

Modifiers

Other ingredients are added to shampoo formulas to modify specific characteristics. Opacifiers are added to make the formula opaque and give it a pearly look. Materials known as sequestering agents are added to offset the dulling effects of hard water. Acids or bases such as citric acid or sodium hydroxide are added to adjust the pH of a shampoo so the detergents will provide optimal cleaning.

Special additives

One of the primary factors that influence the purchase of a shampoo is its color and odor. To modify these characteristics, manufacturers add fragrance oils and governmentally approved and certified FD&C dyes. Other special additives can also have a similar effect. Natural materials such as botanical extracts, natural oils, proteins, and vitamins all impart special qualities and help sell shampoos. Additives such as zinc pyrithione are included to address the problem of dandruff. Other additives are dyes which can color the hair.

Shampoo formulas seek to maximize these attributes: easy rinsing , good finish after washing hair, minimal skin/eye irritation, no damage to hair, feels thick and/or creamy,smells good, low toxicity, good biodegradability, slightly acidic ph, since a basic environment weakens the hair by breaking the disulfide bonds in hair keratin. Many shampoos are pearlescent. This effect is achieved by addition of tiny flakes of suitable materials, eg. glycol distearate (a wax).

Surfactants, also known as wetting agents, lower the surface tension of a liquid, allowing easier spreading, and the interfacial tension between two liquids. The term surfactant is a contraction of “Surface active agent”. The major types of surfactants used in shampoos include: Anionic, Cationic, Nonionic, Amphoteric . In the USA, the Food and Drug Administration (FDA) mandates that shampoo containers accurately list ingredients. The government further regulates what shampoo manufacturers can and cannot claim as any associated benefit. While the claims may be substantiated, the testing methods and details of such claims are not as straightforward. For example, many products are purported to protect hair from damage due to ultraviolet radiation. While the ingredient responsible for this protection does block UV, it is actually not present in a high enough concentration to be effective. Though sun rays can damage hair, there is no proof that any illness or disease can grow in the hair. Dandruff Shampoos are specifically for those who have dandruff. These contain fungicides such as zinc pyrithione and selenium sulfide which reduce loose dander by killing Malassezia furfur. Coal tar and salicylate derivatives are often used as well.

All-natural shampoos

Some companies use “all-natural”, “organic” or “botanical” ingredients (such as plant extracts), often combining these additions with a typical surfactant.

Alternative shampoos

Alternative shampoos, sometimes labeled SLS-free, have fewer harsh chemicals – typically none from the sulfate family.

Solid shampoos

Shampoo is also available in solid form, allowing it to be rubbed onto the hair. This has the advantage of having the shampoo easily carried, but also has the disadvantage of working less efficiently on longer hair.

Hard & Soft Water

Rainwater is soft and mineral free, but as it seeps through the ground it picks up minerals from the soil and rocks, which give it its character. By definition, if water passes through hard rock or peat, it maintains its softness; conversely, the softer the rock the harder the water as it collects minerals, principally calcium and magnesium, along the way.

We have all experienced the difference in the application of product & the condition and manageability of our hair in varying water areas. Simply put, hard water makes it more difficult to get a lather encouraging excess product. As a result, hair tends to be drier and more prone to damage. In soft water areas, you need minimal amounts of product and more rinsing, and the effects are that the locks can be flatter and more difficult to style. You must explore and try to find a shampoo that works with the water you are using, and continue using it until the water situation changes, if at all.

It’s no surprise that the occurance of cancer has increased over the last one hundred years with all of these chemicals being introduced to products due them being cheap for the manafacturers. But yet, we as humans have been cleaning our hair thousands of years without them. Try and get away from the foam and lather craving. They are just empty bubbles of trouble. The truth is the cosmetics industry is very poorly regulated. With the exception of a handful of extremely toxic chemicals, manufacturers can put almost anything in their cosmetics without testing to see if the ingredients are harmful. The Food and Drug Administration (FDA) can only make suggestions or recommendations to manufacturers about cosmetic products or their ingredients, but the manufacturers donit have to follow them. Here are a few products that are great and safe.

I like Burt’s Bees Color Keeper Green Tea & Fennel Seed Shampoo for color treated hair. This natural formula has Coconut and Sunflower oil to create a cleansing complex that is effective, gentle, and richly foaming. Green tea extracts provides natural protection from sun damage. Fennel Seed and Jewelweed extracts moisturize and repair color-treated hair, and leave hair shiny, vibrant, and maintaining color.

I also like Avalon Organics shampoos. They are a natural company that has different types of shampoos for all different hair types. Lavender for nourishing effects, peppermint for revitalizing, lemon for clarifying, rosemary for volume, tea-tree for scalp, ylang-ylang for shine & luster, mango for moisture, and B-complex for strengthening. The B-Complex is specifically designed to rejuvenate and restore thinning hair. This thickening shampoo is fortified with an elixir of biotin, saw palmetto and wheat protein to control hair loss, while nourishing follicles and restoring thinning hair. It will also strengthen hair strands and boost body and volume for a healthy scalp and thicker, fuller hair. Made with a healing complex of B vitamins to heal and stimulate the hair and scalp. With biotin to provide body and shine to hair, niacin to heal and nourish the hair while increasing scalp circulation and stimulating hair follicles, and Panthenol to deeply moisturize the hair. This thickening shampoo is formulated with aloe and jojoba in addition to biotin, B vitamins, health-promoting saw palmetto and smoothing, softening wheat protein.All of these products are natural and very effective.