Shampoo may contain many different types of toxic chemicals. And the more promises your shampoo makes, like frizz free, shiny, extra volume, the more chemicals it contains.
But in general, the toxic chemicals in shampoo include fragrance, preservatives, foaming agents and phthalates.
Considered to be trade secrets, the chemicals used to make fragrances are not disclosed to you on the labels. But some of the commonly used fragrance chemicals, like lilial, are endocrine disruptors. Other toxic fragrance chemicals include benzyl salicylate, coumarin, limonene, and linalool.
Diethanolamine (DEA) and Triethanolamine (TEA) are cancer-causing chemicals used to make shampoo foamy. (example- Cocamide DEA)
About half of all personal care products contain 1,4-dioxane. Because during the manufacture of shampoo, some chemicals become contaminated with the carcinogen 1,4-dioxane. These include PEG/ PPG-18/ 18 Dimethicone, sodium laureth sulfate, polyethylene glycol (PEG)-polypropylene glycol (PPG), Polyoxyethylene, dimethicone and chemicals that include the clauses xynol, ceteareth and oleth.
Parabens are endocrine disrupting preservatives in shampoos. They include methylparaben, propylparaben, isopropylparaben, butylparaben, isobutylparaben.
Some preservatives release formaldehyde, a carcinogen, to keep shampoo from spoiling. These include DMDM hydantoin, imidazolidinyl urea and diazolidinyl urea,
Methylisothiazolinone is a preservative associated with allergic reactions. methylisothiazolinone may also be neurotoxic and it’s a known human immune toxicant.
These endocrine disrupting chemicals are used to make fragrance. They are not listed on the label.
The most common types of siloxanes used in shampoos are octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). D4 is linked to reproductive impairment, liver changes, and uterine tumors, and it may be an endocrine disruptor. D5 is linked with uterine cancers and adverse reproductive, neurological, and immune effects. D6 is linked to liver and thyroid enlargement, and reproductive issues.
To learn more check out Why Natural Shampoo And Conditioner Is A Healthy Choice.