I thought it would be interesting to deconstruct a shampoo formula. To do that, we need to begin with the formula. Here’s a nice, simple formula that I used to work on. I’ve removed all of the superfluous things and stuck to the ingredients that are critical for making the product.
VO5 NORMAL SHAMPOO
Ingredients: Water, Sodium Lauryl Sulfate, Cocamidopropyl Betaine, Ammonium Chloride, Sodium Laureth Sulfate, Fragrance, DMDM Hydantoin, Citric Acid, Tetrasodium EDTA, Yellow 6 (CI 15985), Sodium Chloride
The bulk of this (and almost all other shampoos) is water. In fact, it probably makes up 80-90% of the formula. When you make a shampoo you can take the water right from the city water supply. You may have to run it through a deionizer but if your city has decent water, that’s where you’ll get it. VO5 shampoo was made primarily in Melrose Park, IL so the water used to make it came from Lake Michigan.
Source: Lakes, rivers, underground aquifers, & any where else you might get fresh water
Sodium Lauryl Sulfate
This detergent is what makes the shampoo clean. We’ve previous talked about surfactant science so I’ll focus on where this ingredient comes from. To create Sodium Lauryl Sulfate (SLS) you need to do the following reactions.
1. Lauryl alcohol + sulfuric acid ——> hydrogen lauryl sulfate
2. Hydrogen lauryl sulfate + Sodium carbonate ——> Sodium lauryl sulfate
So, to make this detergent you need 3 starting materials including, Lauryl Alcohol, Sulfuric Acid, and Sodium Carbonate. To get Lauryl Alcohol you start with an oil either a petrochemical or Coconut Oil. You distill out the C12 molecules and then run those through a high pressure hydrogrenation reaction to produce the lauryl alcohol.
To get Sulfuric Acid you need to start with Sulfur (mined somewhere), burn it to produce Sulfur Dioxide, then oxidize it in the presence of a Vanadium Oxide catalyst to produce Sulfur Trioxide. That material is dissolved in water to get Sulfuric Acid.
Sodium Carbonate is directly mined. The United States and Turkey have large deposits of the stuff.
Source: Coconuts and mined materials.
This is a secondary surfactant that helps thicken the system, make the foam a bit more creamy, and reduce the irritation potential of the main detergents. To make it you have to start with Coconut oil again. Coconut oil is fractionated to remove the Lauric Acid. This is reacted with Dimethylaminopropylamine which comes from Dimethylamine (obtained from a reaction between Methanol and Ammonia) and Acrylonitrile (produced from a reaction between ammonia and propylene). The result is further reacted with Chloroacetic acid (made from Hydrocholoric acid and Acetic Acid) to make Cocamidopropyl Betaine.
Sources: Conconuts, mined materials, fermented materials
This is the primary salt which helps to thicken the formula. It is obtained as a byproduct from the creation of Sodium Carbonate. The materials needed include Carbon Dioxde (air), Ammonia (air), Salt (mined) and water.
CO2 + 2 NH3 + 2 NaCl + H2O → 2 NH4Cl + Na2CO3
Sources: Air and water
Sodium Laureth Sulfate
This is made pretty much the same way as Sodium Lauryl Sulfate except the Lauryl Alcohol is reacted with Ethylene Oxide (derived from petroleum) prior to reacting it with Sulfuric Acid. This helps to reduce the irritation potential of the ingredient.
Sources: Coconuts, Petroleum
Fragrances are added to make the product smell better. In reality, fragrance materials come from so many sources that it would be difficult to explain it all here. Plus, fragrances are so varied and have so many ingredients that it wouldn’t help much. Suffice it to say there are both synthetic and natural sources of the materials used to make fragrances.
Source: Plants & petroleum
Here’s the primary preservative in the formula. You need it to control any types of microbes that can infect your formula. Hydantoin originally was produced from Allantoin which is how it got its name. But it is primarily produced from reacting Glycolic Acid with Urea.
To adjust the pH of the shampoo, formulators add an acid like citric acid. While citric acid can be obtained from citrus fruits the primary source is bacterial fermentation of sugars.
Source: Sugar & bacteria
This is a chelating ingredient that helps remove ions from hard water and helps the preservative work better. This useful molecule is the result of a chemical reaction between Ethylenediamine, Formaldehyde, and Sodium Cyanide. Sounds scary when you say that. However, Ethylenediamine comes from Ammonia and Ethane, Formaldehyde comes from Methanol, and Sodium Cyanide comes from Sodium Hydroxide and Hydrogen cyanide (obtained from Methane and Ammonia)
Source: Air, Petroleum
Yellow 6 (CI 15985)
To give the shampoo it’s nice orangish / yellow color, they use Yellow 6. This is a pretty complicated molecule and I don’t have a good sense of how they even make it. No doubt ammonia and petrochemicals are involved.
This helps with the thickening. It comes from salt mines mostly.
Source: Mines or the ocean
So there you have it. If you want to make your own shampoo from scratch you could do it with the following starting materials.
Of course, if you want to spend your time optimizing the formula, it would be a much better idea to start with the finished compounds rather than the exact starting raw materials.