SLS & Skin - Sodium lauryl sulphate is a known irritant and is actually used in clinical studies for that purpose - to irritate the skin so that the effects of other substances can be tested. When applied to human skin it has the effect of stripping off the oil layer then irritating and eroding, leaving it dry, itchy and sometimes inflamed. It cleans by corrosion and dries the skin by stripping the protective lipids from the surface so it can not effectively regulate moisture balance. SLS can also aggravate more serious skin conditions like eczema and dermatitis.
SLS & Eyes - In experimental, acute eye tests, a solution of 10% sodium lauryl sulphate caused corneal damage to the eyes if not irrigated or irrigation was delayed. A solution of 5.1% caused mild irritation. Studies have also shown that SLS could retard the healing and keep childrens eyes from developing properly by denaturing the proteins and not allowing for proper structural formation. Children under six years old are especially vulnerable to improper eye development. It has also been said that SLS could cause cataracts in adults and delays the healing of wounds in the surface of the cornea.
SLS & Hair - Because sodium lauryl sulphate is such a caustic detergent it can cause scalp irritations, corrode the hair follicle - impairing the ability for hair to grow, and strips moisture from the delicate hair shaft, leaving it dry and brittle. SLS & Science - Sodium lauryl sulphate has a low molecular weight of just 40, ingredients under the weight of 75 enters the body. Therefore SLS can rapidly be absorbed into the body and be retained in the eyes, brain, liver and heart, which may result in harmful long term effects.
SLS & Ethoxylation - When SLS goes through a process called ethoxylation (this is where the degreasing agent becomes less abrasive gives it enhanced foaming properties) this compound then becomes Sodium Laureth Sulphate (SLES). The problem here lays with the fact that ethoxylation causes residues of a compound called 1, 4-dioxane to form. 1, 4-dioxane has shown in tests to be carcinogenic in rats and mice and is absorbed through the intact skin of the animals. Furthermore, this compound has been classified as a possible carcinogen in humans. According to the European Economic Community directive on cosmetics, 1, 4-dioxane must not be present in commercial products. Consequently, the assay of this substance in marketed cosmetics is of a direct concern.
Parabens are a group of chemicals widely used in the cosmetic industry, it is reported that 99% of beauty products contain them. They are preservatives that inhibit the growth of bacteria, fungus and mould, to extend the shelf life of a product. The most commonly used parabens in cosmetics are methylparaben, propylparaben, ethylparaben and butylparaben. Parabens may cause skin irritation, cause allergic reactions and interfere with the intestinal flora which is vital for the cleanliness of the intestines. Recent research suggests that parabens are able to mimic the action of the female hormone oestrogen, so there is a link with breast cancer, although this has not been proven and further studies are needed.
Phthalates are chemicals used in many toiletries to help the fragrance last longer. It is estimated that around 90% of beauty products contain these symthetic preservatives. Animal studies on certain phthalates have shown the chemicals may cause a variety of problems, including reproductive and developmental harm, organ damage, immune suppression, endocrine disruption and cancer. The major concern is that as phthalates are so ubiquitous in our environment, no one knows for sure what the long term exposure, even in small doses, may be doing to human health, particularly developing infants. Phthalates are so widely used that it may be nearly impossible to eliminate your exposure entirely. However, we feel just by omitting them from the cosmetics we use will make a difference. Phthalates may be listed as: Dibutyl phthalate (DBP), Diethyl phthalate (DEP), Butylbenzyl phthalate (BBP).
A recent study conducted at the University of Washington in Seattle has shown that potentially harmful phthalates (plasticisers) are absorbed through childrens skin. All of the 163 urine samples from infants up to 28 months contained at least one phthalate, and 81% had seven or more. High doses of phthalates have been known to produce unnatural hormone activity in tests.
Propylene Glycol (PG) is a colourless, nearly odourless syrupy liquid that is derived from a natural gas, that is commonly used in anti-freeze and brake fluid! It has found its way into cosmetics as a binding agent. It penetrates the skin and can weaken protein and cellular structure. It is considered so toxic that it requires workers to wear protective gloves, clothing and goggles when being handled. Because Propylene Glycol penetrates the skin so quickly, the Environmental Protection Agency (EPA) warns against skin contact to prevent consequences such as brain, liver and kidney abnormalities.
Oxybenzone (also known as benzophenone-3) is the widely used chemical in many sun products with high sun protection factors, its function is to 'filter' ultra violet light on the surface of the skin, converting it from light to heat, but it can also be absorbed through the skin. As yet there has not been any conclusive research to indicate what happens when the oxybenzone is absorbed through the skin, but UV light causing cell damage is well known and you may choose to avoid this form of sun protection. If light is converted to heat in the basal layers of the skin, damage to growing cells is very likely.
Formaldehyde is a toxic, colourless gas that is an irritant, and a carcinogen. When combined with water, formaldehyde is used as a disinfectant, fixative or preservative in deodorants, liquid soaps, nail varnish and shampoos. Also known as formalin, formal and methylaldehyde, it is a suspected human carcinogen and has caused cancer in rats. Formaldehyde can damage DNA, irritate the eyes, upper respiratory tract and mucous membrane, and may cause asthma and headaches. It is banned in Japan and Sweden.
Nitrosamines are not intentionally added to cosmetics, they are contaminants accidentally formed during either manufacture or storage if certain ingredients are combined. There are NO safe levels of these chemicals and whats even more worrying is that they are able to penetrate the skin. Products to watch out for are those containing amines or amino deerivatives, particularly di- or triethanolamine (DEA, TEA, MEA see below), which may form nitrosamines if combined with an ingredient which acts as a nitrosating agent, e.g sodium nitrate. Amines and their derivatives are mostly present in creams, cream lotions, hair shampoos and cream hair conditioners. Beware of mixing products.
Diethanolamine (DEA), Monoethanolamine (MEA), Triethanolamine (TEA) are hormone disrupting chemicals known to form nitrates and nitrosamines, often in conjunction with other chemicals present in a product. They are almost always present in cosmetics that foam: bubble bath, shampoo, body wash, soap. Dr, Samuel Epstein, Professor of Environmental Health at the University of Illinois, reports that repeated applications of DEA based detergents result in increases in liver and kidney cancer.