By Doug Millar B.Sc.
Clay masks come in lots of different colours, but why and what does this mean for me?
The colours and what do they mean
Masks come in lots of different colours from White to Pink or Red to Green, Brown and even Black. The different colours are caused by contain different minerals and additives, sometimes naturally occurring within the clays but more often they are added synthetically during manufacture for effect. The important thing is not the colour, but the type, purity and the strength of the clay that is important in high quality skin care products.
White clay is the most likely to be made without any synthetic colourants or additives. Sometimes, however, it will have Titanium Dioxide (sometimes known as CI 11891) added which is an ingredient used in other industries including house paint, colour cosmetics, sunscreens etc. Titanium Dioxide is a mineral which occurs in nature, but is normally produced synthetically for skin care products.
Iron oxide describes a range of different coloured material that are often added to clay masks to get a particular colour or effect. Commercially the are produced synthetically under highly controlled conditions and changing these conditions changes the chemical structure which in turn gives a different coloured product.
Iron oxides are the key colourants in many clay products including most Pink, Red, Yellow, Brown and some Black masks. In the USA they have the names Red Iron Oxide , Yellow Iron Oxide and Black Iron Oxide and in much of the rest of the world the are called CI 77491, CI 77492 and CI 77499.
Green Clay normally contains Chromium Oxide which is a heavy metal. Chromium itself is known to be toxic but in its Oxide form it's pretty safe.
There are also some shimmery ingredients in some clay products which use mica in combination with Titanium Dioxide or Iron Oxide. Mica is a naturally occurring mineral that occurs as very flat structures and when processed the right way with the right colourants added they essentially act like tiny mirrors reflecting light causing a shimmery effect.
So what does that mean for the user of the products?
Essentially whether the colours are added for effect or they occur as natural contaminants in the products they simply give the products a different colour but (other than charcoal) they add no efficacy to the finished product. A product with no colour added will often be purer product that is a pretty colour.
Doug has over 25 years of experience in the personal care industry manufacturing and Research and development, creating formulations and working with companies from small start-up brands to large multinational household names.
He currently runs his own formulation laboratory where he creates bespoke formulations for a wide range of clients. www.cosmeticscienceau.com.