Chemicals that interfere with our hormones and make it harder to get pregnant, chemicals that cause cancer, and chemicals that can make us develop asthma are, unfortunately, normal ingredients in cosmetics and personal care products.

This is one of the conclusions from the collaboration between ChemSec and Clearya – an online shopping app and browser plugin. It automatically analyses the ingredients lists of cosmetics and personal care products sold in major online shops, such as Amazon, and notifies shoppers if they contain any harmful chemicals.

“As a result of ChemSec’s collaboration with Clearya, we now know which the most common SIN chemicals in cosmetics are”

The harmful chemicals are defined by authoritative regulatory or scientific sources. And since May this year, ChemSec’s SIN List is one of those sources.

“In total, 40 different SIN substances were found in the ingredients lists”

The SIN List is ChemSec’s compilation of nearly 1,000 hazardous chemicals used around the world that should be avoided due to the fact that they fulfil the criteria for Substances of Very High Concern as defined by the EU chemicals regulation REACH.

As a result of ChemSec’s collaboration with Clearya, we now know which the most common SIN chemicals in cosmetics are.

Even if these numbers are based on the US market where chemicals in cosmetics and personal care products are much less regulated, it doesn’t mean that Europeans are spared – many hazardous chemicals are allowed in EU cosmetics as well.

Of 40,000 personal care products, Clearya found that more than 6,000 contained at least one ingredient from the SIN List – many of them had more than one SIN substance. In total, 40 different SIN substances were found in the ingredients lists.

Here are the 15 most common SIN chemicals found in Clearya’s sampled cosmetics and personal care products (in order of occurrence):

“Because it’s so urgent to reduce the exposure to these chemicals, it’s very sad to see that many personal care products still contain them”

1. Butylated hydroxytoluene – an endocrine disruptor (EDC), meaning that it affects the hormone system. In cosmetics, it is used as a preservative.
2. Propylparaben – another EDC commonly used as a preservative.
3. Octinoxate – a hormone-disrupting UV filter, often found in sunscreens, that goes by the name 2-ethylhexyl 4-methoxycinnamate in the EU.
4. Oxybenzone – also a hormone-disrupting UV filter.
5. Butylparaben – an endocrine-disrupting preservative that is found on the EU Candidate List, which is the first step towards a restriction in the EU.
6. Resorcinol – an EDC that also causes allergies. It is especially used in hair dye.
7. Cyclotetrasiloxane – a conditioning agent which is an EDC and also PBT, meaning that it is problematic in the environment.
8. Benzophenone-1 – a hormone-disrupting UV filter.
9. Borax – used to regulate PH. It is toxic for reproduction and listed on the EU Candidate List.
10. BHA – an endocrine-disrupting antioxidant used as a preservative.
11. Triphenyl phosphate – a hormone disruptor used as a plastic softener.
12. Octoxynol-9 – an EDC that is found on the EU Candidate List. In cosmetics, it is used as a surfactant.
13. Triclosan – a much-debated antibacterial substance frequently used in tooth paste.
14. Formaldehyde – a cancer-causing chemical used as a preservative. Formaldehyde is not allowed in EU cosmetics.
15. Octoxynol-10 – an EDC that is found on the EU Candidate List. In cosmetics, it is used as a surfactant.

The majority of these chemicals affect the hormone system and can cause detrimental effects in people such as reduced sperm quality in men and an early onset of puberty in girls, which can lead to a greater risk of getting breast cancer later in life.

“The more we learn about endocrine disruptors, the more we understand that they’re closely linked to some of the greatest health challenges of our time – such as cancer, obesity, infertility and neurological disorders. Because it’s so urgent to reduce the exposure to these chemicals, it’s very sad to see that many personal care products still contain them”, says Dr. Anna Lennquist, Senior Toxicologist at ChemSec.