Article by: Perry Romanowski
Show Notes –
Interview – Chris Boone
Chris Boone is a cosmetic scientists who specializes in solving problems in the area of formulation, product development and innovation. He has worked with Unilever and Alberto Culver as a formulator and also worked on the supplier side with the McIntyre (now Rhodia) group. Currently he is a technical services specialist at Nexxeo solutions.
You can connect with Chris on LinkedIn
Cosmetic industry stories
Reactive cosmetic products
While most of the chemical reactions in our industry occur at the raw material suppliers labs, there are some cosmetic products specifically designed to chemically react. Here’s a list of the most common.
These products are designed to permanently change the shape of hair. People with straight hair often use permanent waves to get a little curl in their hair. A permanent wave formula has a reducing agent like thioglycolic acid that reacts with the di-sulfur bonds in the cystine amino acids breaking down the hair structure. Hair is first shaped into curlers, then the product is put on hair. It begins reducing hair and is rinsed with water to stop the reaction. A neutralizing chemical like hydrogen peroxide, is added which reforms the di-sulfur bonds into the new configuration.
These products do the opposite of permanent waves. They make curly hair permanently straight. The method is similar you chemically break down hair, reshape it, then reform the protein bonds in the new configuration. Sometimes ammonium thioglycolate is used but most often it is sodium hydroxide or lithium hydroxide. The compounds break down the di-sulfur bonds in hair and the neutralizing step stops the reaction.
This is the most damaging chemical treatment for hair.
Hair bleaching is a process used to turn brunettes into blonds. You didn’t really think that there were that many blonds in the world did you? Hair bleach is a chemical reaction between melanin (the material in hair that gives it color) and hydrogen peroxide.
Hair coloring is a slightly more complicated version of hair bleach. It uses hydrogen peroxide to break down hair’s natural color, then the peroxide also oxidizes a polymeric reaction with dye monomers. When the dye polymerizes inside the hair, it creates a color molecule that is too big to easily come back out.
These products are designed to give fair-skinned people a tanned look. They work by using an ingredient called dihydroxyacetone or DHA. It reacts with the proteins in the stratum corneum via the Maillard reaction to produce the brown (although sometimes orange) color. All the steps haven’t been worked out, but basically when DHA is exposed to skin protein, it is converted to pyruvaldehyde, which then reacts with arginine, lysine, and histidine amino acids in skin to form brown/yellow pigments called melanoidins.
These are products designed to help people to remove unwanted hair. The primary active in these types of cosmetics is some version of thioglycolic acid. The acid reacts with the cystine amino acids in hair and breaks down the S-S linkages. The hair is reduced to a jelly like mass that can then be wiped away. Note this is the same reaction as in permanent waves.
2SH-CH2-COOH(thioglycolic acid) +R-S-S-R(cystine)–—> 2R-SH + COOH CH2 SS CH2 COOH (dithiodiglycolic acid)
National SCC year end scientific meeting
Chemists Corner is a podcast about cosmetic science and is broadcast to help educate, entertain, and inspire current and future cosmetic scientists. The information and opinions discussed on Chemists Corner are those of the hosts and the guests alone. They do not necessarily reflect those of any past, present or future employers.