If you make your own lotions from scratch – instead of using a pre-made cosmetic base – you will become familiar with the terms acid and alkali. As you advance in lotion making, you may want to perfect your bath and body recipes to find the “right” pH level for your lotions. This post briefly describes the difference between an acid and an alkali for such purposes.
The pH Level of Lotions
The pH scale is the measure of acidity and basicity in an aqueous solution. Pure water has a pH of approximately 7. Solutions with a pH level below 7 are determined as acidic whereas solutions with a pH level above 7 are determined as a basic or alkaline.
What is an Acid?
Acids are present in our bodies, in foods, and in many common household items. An example of an acid in the body is hydrochloric acid in the stomach. Acids prevent natural bath and body products from becoming too alkaline.One of the most common acids you will find when making bath and body products is citric acid.
Citric acid is a weak, organic acid. It is a white crystalline powder that is sometimes used as a natural preservative in bath and body products. Citrus fruits – such as lemons, limes , and oranges – contain high levels of citric acid.
What is an Alkali?
An alkali may materialize in the form of a basic salt. Examples of alkali salts include sodium hydroxide and potassium hydroxide (sometimes known as lye). One of the most used alkali bases in bath and body product making is sodium bicarbonate – also known as bicarbonate of soda. If your lotion base is too acidic, add sodium bicarbonate to neutralize the high acidity.
Sodium bicarbonate is a white, crystalline solid but appears as a white, fine powder for cosmetic purposes. It is used in bath and body products to smooth the skin and act as a deodorant.
Testing the pH level of Your Homemade Lotions
The pH level of lotions is usually between 5.5 – 6.5, although this can vary. Some cosmetic suppliers state the pH level of their lotion bases on the label of the product. If you are making your own lotion base – and want to test the pH level of a recipe you’ve prepared – you can use a portable pH meter to do so. These vary in price but are usually under $50. You can use portable pool pH level meters for this purpose.
Learn to Make Your Own Bath and Body Products
If you are new to making your own bath and body products, you might be interested in one of the introductory Sedona Aromatherapie home study courses in making bath and body products – or one of the more advanced courses. To learn more, please visit the courses home page.
TutorVista.com, Acids Bases and Salts, accessed January 27, 2014
Author’s own experience and research