Soap: Ingredient Declaration

This article applies to lye/oil soap which IS a cosmetic

When creating an ingredient declaration for a lye/oil soap, you have the option of declaring what goes INTO the pot, or what comes OUT of the pot. What goes into the pot ("starting ingredients")are the individual ingredients you dumped into your pot. What comes out are the "reaction products" -the result of a chemical reaction (saponification) which creates a new thing –the soap itself.

INTO the Pot

Listing what goes into the pot is quite straightforwardand simple to do. You just look at your formulation and list all the ingredients in descending order of predominance. See Cosmetic Labeling: Ingredient Declaration for a full discussion of the requirements.

Example:

OUT of the Pot

Listing what comes out of the pot (the "reaction products") is a little bit trickier and requires an understanding of both soap chemistry and basic math.

Using the ingredients from the example above, the olive, palm, and coconut oils react with the sodium hydroxide and water. If all the oils were 100% saponified, the result would be saponified olive oil, saponified palm oil, saponified coconut oil, glycerin, and water. Using the correct names for these, the ingredient declaration would be:

See the HSCG Ingredient Database for the correct name for each saponified oil.

Unfortunately, in handcrafted soap, the oils aren't usually 100% saponified.¹ We leave some of the oil unsaponified (by using a lye discount or super-fat) to improve the soap. That's great for the consumer, but it makes it more difficult to craft a correct ingredient declaration that accurately reflects what comes out of the pot.

The oils that are used in soapmaking are triglycerides. During the soapmaking process, the triglycerides are broken apartinto a fatty acid connected to glycerin. Most then connect up with sodium hydroxide, where the fatty acid combines with the sodium hydroxide making soap and freesup the glycerin. But some of the broken-apart triglycerides remain. That's the "super-fat" left in the soap. They mostly aren't whole triglycerides anymore; they are singles (mono-glycerides) or doubles (di-glycerides) and could be made up of any one of the fatty acids that made up the original oil.

They can be identified in the ingredient declaration by the name used in the International Cosmetic Ingredient Dictionaryfor the glycerides of the oil.

Example:

Alternatively, they can be generally identified by the name used in the Food Chemical Codex.

Example:

Calculating the Amounts

The formulas for calculating the amounts of the out-of-pot ingredients are below. These will give a reasonable approximationof the amounts so you can correctly place them in descending order of predominance.