Behind the Face Mask - Clay

A facial Mask is a rinse off treatment that you apply to your skin for between 5 - 20 minutes depending on how the mask has been formulated. Some face masks are formulated to be left on longer again this is dependant upon the intended formulation outcome. For instance a clay or mud masque is intended to draw out impurities // oil and is left on for a short period, other masques are formulated to hydrate the skin and can be applied to the skin for a longer time period. Face Masques do not pull out 'toxins' they pull out dirt, oil, impurities and help remove the surface layer of dead skin, hence the soft skin feeling after use.

What is Clay?

The definition of clay: An earthy material that is plastic when moist but hard when fired, that is composed mainly of fine particles of hydrous aluminum silicates and other minerals. Clays posses a cation-exchange capacity (CEC) and sorptive properties. They can either absorb or adsorb or both. What makes different clays unique is their mineral composition, varying CEC rates, and their ability to absorb//adsorb.

How do face masks actually work

Absorb means a process by which a substance is taken into another substance, this mean that clays can actually alter the other ingredients in the formulation deactivating their effect. When a clay absorbs, it means that the clay is pulling things into itself. The more a clay absorbs, the more it swells. 
When a clay adsorbs, it means it is pulling things onto it's surface only. Clays that only adsorb will not draw oils from the skin.


  • Oil absorbing
  • Water absorbing
  • Volatile matter (odour) absorbing
  • Modifying texture (of a cosmetic formulation)
  • Modifying flow (rheological properties of a cosmetic formulation)

What Clay Masks Do for the Skin

different colored cosmetic clays

BENTONITE CLAY - Is a sedimentary clay composed montomorillonite and volcanic ash. There are two types of bentonite clay used in skin care: Sodium Bentonite and Calcium Bentonite (Fullers Earth). Sodium Bentonite swells up to 14 times its size when mixed with water. Contains over 50 trace minerals. 

RHASSOUL MUD (also known as Morrocan Red Clay) Is extremely absorbent effective at absorbing fat and dirt from the skin, it comes from ancient deposits in the fertile Atlas mountains of Morocco and has been used for centuries as a cleanser and conditioner for the skin and hair due to it's high silica content

MONTMORILLONITE (also know as Fullers Earth) - Is well known for its healing and detoxifying powers. The strong negative charge present in this means it is highly absorbent. The essential difference between bentonite and fuller's earth is in their modes of occurrence and their physical properties. Bentonite is regarded to have been formed by the alteration of volcanic ash deposits, mostly in upper Cretaceous formations. Fuller's earth represent a shaly facie of Tertiary rock. 

GREEN CLAY (also known as French Green Clay Green // Illite Clay) - Contains a variety of minerals and salts including calcium, potassium, dolomite, magnesium, silica, manganese, phosphorous, silicon, copper and selenium. One of the most widely used of the cosmetic clays. It reduces sebum production, absorbs oils and impurities, and is an effective skin exfoliator.

PINK CLAY - This is a blend of white Kaolin and Red Clay. It's high Kaolin content is very good for sensitive, mature or dry skin.

KAOLIN CLAY (also known as China Clay or Ceramin Clay) - Has been mined in the US, France, Germany, England, Czech Republic and China. Kaolin is is found in virtually all powder-based cosmetics and one of the most common cosmetic clays used. It is often white in color but can range in color depending on its combination with other elements. Kaolin clay appears pink-orange in combination with iron oxide, and yellow when in combination with feldspar. One of the mildest of all clays, Kaolin clay stimulates circulation to the skin while gently exfoliating and cleansing. A high silica content helps skin cells regenerate, it adsorbs impurities without removing the skins natural oils, making it great for dry and sensitive skin types.


cosmetic clays for face masks



Clays are mainly sedimentation / volcanic minerals and basically contain some heavy metals as an inherent impurity. The content of the heavy metal impurity varies depending on the geographical location, environmental situation and processing. Lead, Nickel and Arsentic are the main heavy metal impurities. A food grade clay must only contain heavy metals which complying with the legal limits.


Clays contain an abundant of microorganisms (mainly the spores) by nature. Even for industrial processing the contamination is unwanted and clays are cleaned / decontaminated before application.

Methods of sterilization for clays:

  • Gamma radiation (this is not allowed for Organic ingredients) 
  • Ozone gas
  • Autoclaving

Clays are incredibly difficult to preserve as they carry many microorganisms, (along with the nutrients which microorganisms require for growth and survival). Because they are absorbents they can absorb and deactivate most of the known natural preservatives. Often a synthetic (or mixture of different preservatives) broad spectrum preservative is necessary for product safely and to correctly preserve a formulation which contains both Clay and water. Here is an excellent example of preservative issues with a product - A recall in August 2017 was issued for select Dr. Brown’s Natural bottle and dish soap. The soap may have contained harmful bacteria and exposure to bacteria poses a risk of respiratory and other infections in immunocompromised individuals, according to U.S. Consumer Product Safety Commission. Read more here.


If a product contains water and clay (including hydrosols, floral water, aloe vera, goat’s milk which all contain water) or will come into contact with water (e.g a scrub or face mask used with wet fingers) a preservative is essential to help prevent microbes (bacteria, mold, and yeast) growing. Read more about Preservatives HERE. Non-inclusion of a broad spectrum preservative can result in serious health consequences for the end user - YOU. Always read the label and look for a preservative here are some examples: 

  • Benzyl Alcohol 
  • Ethylhexylglycerin
  • Phenoxyethano 
  • Ethylhexylglycerin

If there are non on the Ingredients list the manufacturer is either withholding the full ingredient list or selling a product that is potentially going to be, or is already contaminated with harmful microbes. Contact the Brand and or manufacturer and ask for further information - which they should be happy to provide if they are following Good Manufacturing Practices (GMP). All cosmetics products should be Challenge Tested by a microbiological lab to ensure the preservatives used are offering sufficient protection. 


Until next time

be human | be kind | be you






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