Toxic Ingredients

Last updated: September 2012



Toxic Beauty


There are many thousands of ingredients in this sector, but we chose six problem ones to focus on for this report as they were prevalent across all the different cosmetics and toiletries products being reviewed.

We asked all the companies in this report whether they had policies on their use. On our ranking tables, companies that avoided all 6 of them were given a full Product Sustainability mark. Companies that avoided 2-5 of them were given half a Product Sustainability mark.

Some consumers buying cosmetics may want to look for them on the label and try to avoid them. 




Found in most cosmetics, especially shampoos, they are a preservative designed to stop bacteria spoiling cosmetic products. The most common parabens used in cosmetic products are methylparaben, propylparaben, and butylparaben.
Parabens are linked to cancer, endocrine disruption, reproductive toxicity, immunotoxicity, neurotoxicity and skin irritation.[1]
They can be absorbed through the skin, blood and digestive system and have been found in nearly all urine samples from U.S. adults.[2]



Methylisothiazolinone (MIT)


Methylisothiazolinone (MIT) is becoming increasingly popular as a preservative to replace parabens. Big brands, like Nivea’s Pure and Natural range, may claim to be free from parabens but use methylisothiazolinone instead.

Like parabens, it is a preservative that can also release detectable levels of the known human carcinogen formaldehyde.[1] Even some products claiming to be certified organic use this preservative, as certain percentages of non-organic material are allowed by some certifying bodies. Researchers say the early test tube evidence suggests that prolonged exposure to MIT, or exposure to the chemical at high concentrations, could damage the nervous system.[3]



Petrolatum and mineral oil

Mineral oils listed as petrolatum (petroleum jelly) or C-18 derivatives are frequently used in personal care products such as lipsticks, lubricants, baby lotions and oils.

While petrolatum on its own is not too harmful, it is often cheaply produced and the impurities/contaminants often found in petrolatum have been linked to several types of cancer.[10] In the EU, all petroleum products in cosmetics must have their production process certified to ensure they don’t contain these carcinogenic impurities.

Mineral oils are also known to clog pores, forming a barrier preventing skin from eliminating toxins. Repeated use can even set off skin conditions such as acne and dermatitis. It can also block the skin’s ability to moisturise itself, leading to chapped and dry skin, which are often conditions it is sold to alleviate.

Plus, as an ingredient of the petroleum industry, their use contributes to the depletion of a non-renewable resource, not to mention the impacts of oil exploration, drilling, refining and transportation.



Synthetic colours

Synthetic colours used in cosmetics mostly come from coal tar but can also be derived from crude oil or other minerals[.4,5] They contain heavy metal salts that may deposit toxins onto the skin, at the very least causing skin sensitivity and irritation. Some also contain carcinogenic arsenic and lead.[6]

However not all are harmful. The Skin Deep database lists a number of synthetic colours which, in their ranking system, range from 0 (safe) to 10 (very dangerous).



Synthetic fragrances

Synthetic fragrances are commonly used in personal care products and often contain as many as 200 ingredients. These ingredients are, however, considered to be trade secrets, so companies don’t have to tell us what they are. However, studies suggest a number of possible negative effects of the compounds used to create them including:

  • immune system damage
  • a cause and trigger asthma attacks
  • hormone disruption, which can affect development and fertility
  • a potential neurotoxin (chemicals that are toxic to the brain)
  • increase in the proliferation of oestrogen-responsive breast cancer cells
  • they have also been found to be toxic to aquatic life and can accumulate in the food chain.[7]



Propylene Glycol (PEG or PPG)

Found in skin lotion, shampoo, conditioner, baby wipes, soap, make-up. Propylene Glycol is the main ingredient in anti-freeze and is usually listed on cosmetic labels as PEG or PPG.[8]

It is an alcohol which is added to beauty products that claim to hydrate skin, leaving it smooth and soft. However they are considered by many to be a toxin that causes skin rashes and persistent dry, flaky skin and eye irritation. The Environmental Working Group has also linked PEG to various forms of cancer.[9]


The Environmental Working Group is an excellent research and campaign organisation based in the US. It focuses on publishing information on toxic contaminants in consumer products and in the environment. It produces the Skin Deep database which holds information on thousands of cosmetics and their ingredients and is freely accessible to the public.




One of the most widely-used detergents and foaming agents in shampoos, liquid soap products and toothpaste is sodium lauryl sulphate (SLS) and sodium laureth sulphate (SLES).

We did not include SLS specifically in our list of ‘six ingredients to avoid’ because, unlike the other six ingredients, it is not in all the products that we cover in this guide.

There is some controversy about the safety of these ingredients but fears over its link to cancer seem to have been largely discredited, though you’ll still find many supporters of this theory on the web.

The Skin Deep website gives SLS and SLES hazard ratings of 1-2 (low hazard) and 4 out of 10 (moderate hazard) respectively. The website states that research studies have found that exposure to the ingredient itself, not the products that contain it, have indicated potential health risks.

Perhaps the strongest concerns linked to the substances are those of skin, lung or eye irritation, which are related to the concentrations in which they appear in products.

Ammonium Lauryl Sulphate is a milder and safer form which some of the alternative producers use. It is still an irritant but only half as much as SLS and SLES and its molecule size is larger ensuring that these molecules do not penetrate the skin.




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