What Toxins are in My Shampoo?Your bathroom should be a haven of relaxation and a chance to pamper yourself. But despite glossy ads and super-slick models looking radiant, the very products we choose to lather ourselves with could be coating us in toxic chemicals.

Read our low-down on shampoo health hazards.


Diethanolamine (DEA) is a chemical found in shampoos which helps to create the soapy lather. It is also known as a ‘wetting agent’. But if DEA reacts with other ingredients, namely formaldehyde-forming agents, triethanolamin (TEA) and moniethanolamine (MEA), its possible that a substance called nitrosodiethanolamine (NDELA) is formed which is a known carcinogen. NDELA is easily absorbed by the skin and is associated with bladder, liver, and stomach cancers.

Some dyes used in shampoos, including those labelled CI 60730, CI24053, CI15510 and CI17200, are suspected carcinogens and best avoided.

Propyelene glycol is a petrochemical which acts a synthetic binder and softener and is often in shampoos advertised to thicken hair or add body. However, yet again it is a suspected carcinogen and can also cause contact dermatitis.

Formaldehyde, a toxic chemical used as a preservative and is found in many cosmetic products. Some of the common ingredients found in shampoos can additionally act as agents for its production and formaldehyde levels can rise with storage.

Anti-Dandruff Treatments

The chemicals which are used to combat dandruff are basically fungicides. One of the most commonly used is zinc pyrithione which doesn’t seem to cause too much damage when applied topically, but caused an alarming set of health problems in tests when rats swallowed it. Symptoms included muscle wastage, penile prolapse, deformed spines, and hind-limb weakness.


Sodium Lauryl Sulphate (SLS) is found in most hair shampoos and conditioners. It is a strong detergent which acts as a surfactant and also makes it feel ‘soapy’. It’s often masked in shampoo ingredients lists as being derived from coconut.

Lauryl sulphates are compounds which can cause many potential side-effects including skin rashes, hair loss, mouth ulcers, eye tissue damage, or irritation and flaking skin. However, what is more alarming is that when mixed with other ingredients in the cosmetic pot, nitrosamines can be formed which are cancer-causing and easily penetrate the skin and then harboured in the brain, liver, heart and lungs. In fact if a substance called cocamidopropyl betaine is present, the absorption process is actively facilitated.

Hair Wax

One of the ingredients used in hair waxes is paraffinum liquidum – or liquid paraffin. This type of mineral oil can inflame hair follicles and create rashes, and if ingested, can cause problems with the absorption of essential substances. It has also been linked to cancer when combined with another set of chemicals called polyaromatic hydrocarbons.

Hair Dye

Permanent hair colourants contained arylamines, believed to increase the chance of developing cancer of the bladder.

What You Can Do To Avoid Toxins

  • Always read the labels and look at the ingredients
  • Use much less shampoo than you think you need
  • Always avoid getting shampoo in or near your eyes
  • Do not assume that ‘mild’, ‘gentle’, or ‘baby’ shampoos are any safer – many are not!
  • Where possible by natural or organic products