Is Soap Still Natural If Made With Sodium Hydroxide ( Lye)?

"I was searching online for information regarding lye (Sodium Hydroxide) as a few of my customers reckoned soap made with lye couldn't be natural. I found this article on the 'Men's Soap Page'. If you are someone who has concerns regarding lye, this article is from their website which is also worth a visit as they have some very interesting information and articles there."

The short answer is yes, the soap is still natural!


Most soap companies, leave out the use of lye in their ingredients list because of misinformation and fear among consumers. While lye is dangerous to handle in its chemical form, the substance is not considered as an active ingredient in soaps. Lye is neutralized in the process of saponification, the conversion of fat or oil into soap when combined together.

You the consumer deserve to know how your soap was made. Our belief is that helping you understand this substance is our responsibility so you can feel safe and be confident with your purchase decision.

What Is Sodium Hydroxide, Caustic Soda, or Lye?

Sodium Hydroxide is an inorganic compound with the formula NaOH, where Na+ is sodium cations and OH hydroxide anions. It is a colorless liquid, denser than water, and a highly caustic substance that is used to neutralize acids. Toxicity depends on the concentration of the solution and the duration of its contact with tissue. As a consumer, you will never come in contact with it unless you buy the lye solution for your own product manufacturing process.

Sodium Hydroxide is used in manufacturing a number of products and process you already use or benefit from today:

  • Medicines such as aspirin, anticoagulants, and cholesterol-reducers
  • Water treatment process to control water acidity and remove heavy metals
  • Paper recycling process
  • Food and vegetable deskinning and canning process
  • Cleaning and disinfectant products

The Science of Saponification

Saponification is the chemical reaction when fat or oil is mixed with an alkali such as sodium hydroxide, the result of this reaction being soap and glycerin. Or, as UCLA Illustrated Glossary of Organic Chemistry puts it, “The process in which a triacylglyceride is reacted with the aqueous hydroxide ion to form a mixture of glycerol and fatty acid salts (soaps). The reaction mechanism follows the nucleophilic carbonyl substitution pathway.”

Saponification Chemistry Illustration from UCLA

Saponification of glycerol tristearate (a triacylglyceride) with NaOH (lye) yields a soap consisting of one part glycerol (shown in red) and three parts sodium stearate (shown in blue).

As you can see, there is no sodium hydroxide or lye in the finished product, only soap.

 A basic soap recipe just needs a few essential ingredients: Water (distilled or spring), vegetable fat, essential oils for fragrance, and lye (sodium hydroxide) of course.

However, you may want to consider an additional list of ingredients such as coconut oil and shea butter that are beneficial to the skin.

Lye for soap making is easy to get in small amounts, and they is usually sold in the form of flakes or granuals.

There are plenty of soap making recipes and instructions online. When in doubt, Google is your best friend. Be careful and have fun.


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