Updated: Jan 27, 2020
All solid bar soaps are made of the same basic components: lye (sodium hydroxide- the chemical that “saponifies” the oils, turning them into soap), the liquid (usually water or milk), the fats/oils/butters, and sometimes, but not always- additives that provide color and scent.
What is lye, and why is it used in making ALL soaps, even those labeled “natural”?
Lye, caustic soda, potash, sodium hydroxide (or potassium hydroxide for liquid soap) is the name of the chemical that plays a key role in the soap-making process. It the olden days, lye was made by taking the ashes from burnt hardwood, placing it in water, and skimming the top after it settled (hence the name potash). Now, most lye is created in a laboratory, so it’s not technically considered “organic”. It is also very alkaline with a pH of 14 and can burn/irritate your skin and eyes as much as a strong acid can.
Then...Why is lye in my soap?
By the time the soap making process is complete, the lye is gone or converted into a different chemical (ie: soap) during the saponification process. Technically, there isn’t “lye” in soap- only in the raw ingredients.
During saponification, the sodium hydroxide (lye) reacts with the water, producing heat, and is then cooled and mixed with the fats. The lye (NaOH) and water (H2O) reacts with the fats, causing the fats to break down, rearrange molecules and ultimately yield a fatty-acid salt (Na) and glycerol (OH). The lye is split and is no longer “caustic” at the end of the process.
The oils/fats/kinds of butter used to make the soap MATTER.
Most commercial, big brand, factory-made soap producers use tallow (rendered beef fat) or lard (rendered pork fat) as the main fat source in their bar soap. That’s right, you are washing with something whose raw ingredients include the fat of an animal that once moo’d or oinked. Tallow and lard are used because they are inexpensive and create a firm bar of soap. However, just like the lye, the animal fat has changed it’s properties after saponification and is still soap.
Palm oil also creates a firm soap, and although it can be inexpensive, it comes with a high price to the environment and many people surrounding its trade. Deforestation, destruction of ecosystems for many animals, loss of biodiversity, and loss of indigenous people’s homes are a few of the serious costs of palm oil. If you use a soap with palm oil, make sure it came from a sustainable source that helps the local people and the environment.
The fats in the soap also play a role in how sudsy your soap gets while bathing, and how your skin feels after bathing.
Animal fat-based soaps can have a tendency to dry out some types of skin, and most produce only a small amount of lather in cooler water. They are usually a hard, long-lasting bar of soap.
Plant-based oils generally leave the skin feeling softer and produce a fair amount of lather with water at any temperature. Plant-based fats are full of vitamins, minerals, essential fatty acids (like Omega 3), phytosterols, and antioxidants. Many plant oils have antibacterial, antifungal, and antiviral properties that can help with acne, and others have anti-inflammatory properties that can help with rosacea and eczema.
And, of course, use soap made with organic and non-GMO plant fats.
Pay attention to the Additives in your soap
Here is a list of common chemicals that are found in many conventional soaps:
BHT (butylated hydroxytoluene): A preservative used in a variety of cosmetics as well as food that may be toxic to the liver, blood, and central nervous system.
Formaldehyde: A preservative added to soaps, shampoos, and cosmetics, and has been shown to cause cancer in lab animals.
“Fragrance”: A mysterious, generic term used printed on labels meaning “scent”.
Phthalates: a group of chemicals used as solvents in cosmetics and other consumer products that can disrupt hormones, damage the liver, kidneys, lungs, and reproductive system. Phthalates are highly absorbed into the skin.
Parabens: A family of chemical preservatives commonly used in bars of soap that have been known to mimic human hormones and disrupt the function of hormones naturally found in the body. Methylparaben, Propylparaben, Butylparaben
Sodium laurel/laureth sulfate: Sulfates strip the skin of its natural oils and increase penetration of the skin's surface. They are also irritants for people with sensitive skin or eczema.
Synthetic colors: These can be derived from petroleum or coal tar sources, and have been known to be carcinogenic to humans. If there is FD&C (food, drug, and cosmetic) on the label, it is a synthetic color.
Tetrasodium EDTA: Is made from sodium cyanide and formaldehyde that acts as a chelator and protecting fragrance in soap.
Toulene: A petrochemical solvent that affects the brain, nervous system, liver, and kidneys.
Tricoslan: An antibacterial agent known to be an endocrine disruptor and possibly carcinogenic. (Soap may also contain a chemical similar to triclosan called triclocarban.)
Choose a Natural Soap With Sustainable Ingredients (minus the harmful additives)
What you put on your skin gets into your body, your bloodstream, possibly your brain, kidneys, and liver.
Choose your soap wisely.
For natural soaps crafted with love, scented and tinted by nature, use Sessie Naturals bar soaps, shave soaps, and shampoo bars. They are vegan, non-palm, scented with essential oils, and colored with mica or organic powdered botanicals. They contain zero additives that you can’t pronounce that will harm your skin or liver.