1- The chemicals can penetrate through an intercellular lipid pathway. The stratum corneum consists of cells known as corneocytes. The spaces between the corneocytes are filled with lipids (fats). High pH chemical and products will attack and break down the lipids and allow cellular damage.
2- Another pathway for chemicals to be absorbed into the dermis is transcellular, or cell-to-cell, permeation whereby molecules diffuse directly through the corneocytes.
3- Lastly, chemicals can diffuse into the scalp is via rooted hair. The chemicals can diffuse down the follicle into the root where intercellular damage occurs.
How chemicals from colour and other treatments cause damage
When colouring hair including ammonia free, or using chemical treatments on the hair. Chemicals inadvertently will come in contact with the scalp. Through direct contact or during the rinsing process these chemicals become extremely corrosive. Though the contact is not prolonged the damage is usually extreme. Most consumers and stylists are unaware of this damage and therefore it is not addressed.
When was the last time your colorist explained epidermal damage? It can arise as simple as scalp redness, rash, or just as an itchy scalp. Dermal exposure to hazardous agents including natural ammonia free can and will cause a myriad of issues. This damage can result in dry scalp, weakened rooting of the hair, hair loss, and will almost always cause weakened growth and hair regeneration. All chemical changes to hair including keratin straightening treatments, perms, and relaxers use high pH chemicals to chemically change the hair. (see colouring and chemical treatments section ) During these processes cell structure damage at the scalp is unavoidable and inevitable.
During chemical processing of hair, colouring, straightening, perming and relaxing; cell structure damage will always occur. Even when extreme care is taken to ensure that no chemicals directly touch the scalp, we now know through research that scalp cell damage is inevitable. Though direct contact or indirect contact through rinsing you cannot avoid this cellular damage. Cell structure damage can give rise to poor regeneration of existing hair and potential new hair. Environmental factors, applied heat through hot tools, are also a concern when it comes to cell structure damage. This damage can become exponentially worse when you strip away the acid mantle of the scalp.
The acid mantle is a very fine acid film on the surface of the scalp/skin and acts as a barrier to protect the scalp from harmful and hazardous materials. Any disruption to the acid mantle allows for the absorption of these harmful chemicals. Since the acid mantle is directly affected by pH, anything above a pH of 6.5 will engage in destroying this barrier. This increased pH interferes with this protective barrier, separates cells away from each other and results in dehydration, roughness, irritation and flaking. The scalp is left defenseless and susceptible to further cellular damage. Since all chemical changes done to hair requires elevating the pH, as high as 10 with most permanent colour, even high in straightening and perms techniques, the acid mantle is inevitably destroyed.
Even most shampoos, sulphate based and sulphate free have an elevated pH , as high as 10, destroy the acid mantle. Most styling and finishing products are in the same elevated pH range . This is why it is essential to ask for all of your products to be in the pH range of 4.5-5.5. Insist to your stylist to only use products in this range. If the pH is not clearly labelled on the product you should assume that it is alkaline (pH above 7). All Hair pHix products have a 4.5-5.5 and are infused with certified 100% certified organic GMO free Plant Stem Cells.
Dermal absorption is the transportation of a chemical from the outer surface of the scalp/skin directly into the body. The rate of dermal absorption depends largely on the outer layer of the scalp/skin called the stratum corneum (SC). The SC serves as an important barrier and functions by keeping molecules from passing into the skin, thus protecting the lower layers of the epidermis.
Research shows that scalp/skin absorption happens via diffusion, the process by which molecules spread from an area of high concentration to areas of low concentration. Even a very short period of contact time ( as little as seconds ) can cause severe structural cell damage.
Since most chemical salon treatments last over 20 minutes, the direct and indirect contact to the scalp causes severe dermal cell damage. These chemicals can irreversibly damage the acid mantle allowing for further damage. This damage can show up weeks to years later through thinning hair, less hair density, and overall hair health. Some hair loss is directly linked to chemical damage caused by colouring from both ammonia based colour and ammonia free.