Chemistry at Home- Ammonium Thiolactate

Figure 1. Hair with curlers 

Have you ever gone to the hair salon to get a perm and wondered what that strong meaty smell was? Well its a chemical called ammonium thiolactate. It is an organosulfide compound meaning it contains a thiol group which contains sulfur and usually an alkyl group which is what give it the smelly odor¹. It has the molecular formula C₃H₉NO₂S and has many other names it goes by¹.

It is often used in many different cosmetics such as hair dye, perm lotion and hair mousse as a reducing agent². What this means is that sulfur in the compound is giving electrons to an oxidizing agent in a redox reaction². It is also surprisingly used in flavoring of different types of food³. Now for the burning question, how does the chemical in a perm work? Well the reducing properties of the ammonium thiolactate open the cystine disulfide bonds of the keratin in the hair². The hair is then wrapped around hot rollers, where the heat penetrates the weakened hair and shapes it². Once the hair is shaped it an oxidizing agent such as hydrogen peroxide is used to return the cysteine disulfide bonds back together².

Ammonium thiolactate is not overly toxic after all it is used in food flavoring and in mice the lethal oral dose toxicity was found to be ≤1522mg/kg. Some of the health effects for those who are constantly working around the chemical are however at an increased health risk. These health risks include skin irritation which can lead to severe burns, eye irritation and respiratory tract irritation which can lead to bronchial infections if constantly being inhaled^4,5. However those who go to get their hair done every once in while are not likely to experience any of these concerns.

References:

(1) Ammoniumthiolactate.https://pubchem.ncbi.nlm.nih.gov/compound/Ammonium-thiolactate#section=Structures (accessed Jan 26, 2020).

(2) thiolactate, a.; 95%, A.; Thiolactate, A. The Good Scents Company - Aromatic/Hydrocarbon/Inorganic Ingredients Catalog information. http://www.thegoodscentscompany.com/data/rw1361541.html (accessed Feb 2, 2020).


(3) Thiolactic Acid by Penta Manufacturing Company - Food, Beverage & Nutrition. https://www.ulprospector.com/en/na/Food/Detail/16153/406125/Thiolactic-Acid (accessed Feb 4, 2020).


(4) http://152.91.79.3/publications/CAR/new/NA/NAFULLR/NA0700FR/NA721FR.pdf (accessed Jan 27, 2020).


(5) https://cloudfront.zoro.com/enhanced_pdf/ZQ_7nDhelo.PDF (accessed Feb 4, 2020).


Figure 1 source:https://www.pexels.com/photo/person-woman-hairstyle-macro-112782/ (accessed Feb.12, 2020). Creative Commons Zero- CC0