The Harmful Ingredients in Shampoos That You Need To Avoid

Reading Time: 4 minutesAfter a long day, nothing feels as invigorating as a good hair wash. But did you know that the ingredients in your shampoo could be harming you, as well as the environment? We look at the harmful ingredients to avoid in shampoos, as well as what to look for in a baby shampoo. 

harmful ingredients in shampoos

Harmful Ingredients To Avoid in Shampoos


Also called “surfactants” or surface acting agents, sulfates are used to clean the dirt and excess oil on the scalp and cause lathering in shampoos. Sounds great, right? Not quit. Sulfates, like SLS (sodium lauryl sulfate), SLES (sodium laureth sulfate) and ammonium lauryl sulfate, can strip your hair of its natural moisture and can even be hormone disruptors when used for long periods of time. Plus, they can damage the environment; many shampoo producers derive sulfates from palm oil, which is harvested by clearing forests that are often home to endangered species. Also, once these sulfates wash down the drain, they make their way into waterways and can severely affect marine ecosystems and animals.


This is a type of silicone added to hair products that acts as a preventive layer for your hair shaft but over time, it builds up residue on your scalp, which can prevent moisture from entering the hair and can cause scalp irritation and brittle hair. Silicones like dimethicone have also been shown to persist in the environment and are slow to biodegrade, potentially affecting ecosystems and animals. 


Formaldehyde and formaldehyde-releasing preservatives are used in many personal care products, including shampoos, as well as hair-smoothing treatments like Brazilian blowouts and keratin treatments. These chemicals are intended to prevent microbes and bacteria from growing in water-based products. However, they are carcinogenic and have been linked to cancer and allergic skin reactions. 

Look out for these ingredients on the product label: Bronopol, imidazolidinyl urea, DMDM hydantoin, quaternium-15 and diazolidinyl urea are all formaldehyde releasers. 


These are a preservative used in many cosmetic and personal care products but they can be harmful to our health and the environment. Parabens are xenoestrogens, which means that they have a similar composition to hormones found in humans. Xenoestrogens are thought to be hormone disruptors. In fact, scientists even found evidence of parabens in samples of breast cancer tissue. This doesn’t necessarily mean that parabens cause cancer, but we’d be wise to avoid them anyway. Parabens are also linked to environmental harm, as even low levels of butylparaben can kill coral! 


This is an antibacterial agent and preservative that is often found in shampoos, toothpaste, deodorants and more. It’s been known to disrupt hormones, the endocrine system and even the reproductive system – making it especially harmful for pregnant women and children.

Synthetic Fragrances

There’s generally a lot of secrecy around fragrances in cosmetics and shampoos, since they tend to be exclusive to brands. If the fragrance in your products comes from a natural essential oil, the packaging will say so. However, if all the manufacturers tell you about the ingredient is that it’s a “fragrance,” that’s generally a cause for concern. The term “fragrance” allows manufacturers to opt out of including a list of the ingredients used to create that fragrance, because there’s very little regulation around the term. Basically, if a product label lists “fragrance,” you don’t actually know what’s in there, so to be on the safe side, avoid synthetic fragrances!

Synthetic Colours

The ingredients used to create those lovely colours in your shampoos are usually derived from coal tar or petroleum, a clear no-no when we’re trying to reduce our impact on the planet. You can identify synthetic colours on product labels by the terms “FD&C” or “D&C.”


Last on our list of harmful ingredients in shampoos, these are used in hair care products to increase its spreadability and help make the perfume stick to your hair and scalp. However, they are endocrine disruptors, meaning that they can cause early puberty in girls and reduce male fertility. Besides, they are highly dangerous for the environment, persisting in ecosystems and causing fertility issues in animals.

What About Harmful Ingredients in Baby Shampoos?

Naturally, babies’ skin is more sensitive than young children or adults, so you need to be extra careful about what you put on it. Here are some ingredients to avoid in baby shampoos:

baby shampoo

Fragrances and Phthalates 

Fragrances are associated with hormone disruption and skin and respiratory allergies, while phthalates have been linked to reproductive issues and developmental problems in unborn children, as well as asthma and respiratory problems. Go for fragrance-free options. 


These synthetic preservatives are linked to cancer, endocrine disruption, reproductive toxicity, neurotoxicity and skin irritation. 

Avoid any ingredient names ending in -paraben. 


This known carcinogen is thought to be in more than 50% of all baby soaps, especially those labelled “tear-free.” It’s a contaminant that occurs when a surfactant has been “ethoxylated,” or chemically combined with the compound ethylene oxide. When you see the word ‘laureth’, it means it is ethoxylated. This contaminant can penetrate the skin each time you use the product on your baby, and it’s been linked to cancer, reproductive issues and kidney and liver damage. 

Avoid these ingredients: polyethylene, polyethylene glycol, polyoxyethylene, sodium laureth sulfate, ceteareth, oleth, oxynol, -xynol, PEG, ingredients ending with -eth, -oxynol and those containing the words laureth, laureate, myrrh, ceteareth or oleth.


These are known carcinogens.

Avoid these ingredients: formaldehyde, quaternium-15, dimethyl-dimethyl (DMDM) hydantoin, imidazolidinyl urea, diazolidinyl urea, sodium hydroxymethylglycinate, 2-bromo-2-nitropropane-1,3-diol (bromopol).

While chemicals aren’t inherently bad, we need to be aware of those ingredients that are in the products we use, like shampoos, so that we can make more informed decisions that will not harm us or our children, or the planet. 

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