From shampoos to hair dyes, many toxic ingredients in hair products can affect more than just your hair. Learn more about the most dangerous ones that can actually have a big impact on your health.

Make sure that you avoid using any hair products that contain these toxic ingredients in the long run. Even if you think you can’t escape dangerous chemicals whatever you do, avoiding these toxic ingredients in hair products is the right thing to do for your health.

1. Aminomethyl Propanol

Used to adjust pH in many hair products, aminomethyl propanol is safe at concentrations of 2% or below, but many product have higher levels of this potentially dangerous chemicals. The highest risk of toxicity is linked for hair dyes and products that straighten your hair. If the concentration level is above 12%, aminomethyl propanol becomes a potential carcinogenic.

2. Ammonium Persulfate

One of the most toxic ingredients in hair products, ammonium persulfate is often found in hair bleach and other products for colored hair. It’s a known irritant, that can affect your scalp, along with your eyes and nose. Long term exposure to it can potentially cause dermatitis and asthma.

3. Diethanolamine (DEA), Monoethanolamine (MEA), and Triethanolamine (TEA)

This trio of chemicals can disrupt the activity of your hormones. Most often found in shampoos, they can lead to the formation of cancer-causing agents, with a particularly high risk of kidney and liver cancer. DEA can be found in the list of ingredients as Lauramide DEA, Cocamide DEA and Oleamide DEA, all all three can affect keratin, leaving your hair dry and brittle.

More: Dangerous Ingredients in Cosmetics

4. Formaldehyde Donors

The most common formaldehyde donors are imidazolidinyl urea and DMDM hydantoin. While they don’t actually include formaldehyde, they are derived from it, and can have similar effects. They’re two of the most toxic ingredients in hair products because they’re potentially carcinogenic, can trigger asthma, and also cause other allergy and mood related problems.

5. Isopropyl Alcohol

A solvent derived from petroleum, isopropyl acohol is used in shellac, antifreeze... and hair and body products, including sprays and gels. Since it was designed to dissolve oils, it can strip away your scalp’s natural oils, and when inhaled, it can cause headaches, dizziness, and more serious side-effects including nausea, vomiting, and depression.

6. Parabens and Phtalates

Banned in the European Union for more than a decade, parabens and phtalates can hide under many names, from those that include the words to more misleading names like “E216”. They’re a known carcinogen, and can disrupt hormonal activity. Few toxic ingredients in hair products have such a strong link to breast cancer like phtalates and parabens.

7. P-Phenylediamine (PPD)

Most commonly found in hair dyes, PPD is one product that should not come into contact with your skin. Even the most skilld hair colorist might get some on your skin while dying your hair, and exposure to it can cause everything from coughing and headache to high blood pressure and abdominal pain.

8. Proplyene Glycol (PG) and Polyethylene Glycol (PEG)

Found in everything from conditioners to hair dyes, these two glycols are some of the most toxic ingredients in hair products. Both are used to dissolve grease, which is why they’re also found in oven cleaning products, but they’re way too harsh for your hair and can cause skin irritation, while being very dangerous for the environment as well.

See also: Makeup Allergy - Symptoms and Causes

9. Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES)

Used in almost every foaming cosmetic (including shampoo), SLS and SLES have a very long list of side-effects, including eye damage, depression, and diarrhea. Easily absorbed into the body through your skin, they stick around for a few days and can travel to your brain and lungs through the blood stream.

10. Fragrance

Over 4,000 toxic ingredients in hair products can hide under this generic term. Fragrances don’t just cause skin irritation and digestive problems, they can also affect the central nervous system. You’re better off buying unscented products and adding your own essential oils to them.