From cleanser and toner to foundation and lipstick to nail polish and perfume, many of us use a wide variety of beauty products, sometimes even a dozen or more different products each day. But while most people are conscious of what they put in their body, many put less thought into what goes on their body. As a result, people often use beauty products without realizing that they contain harmful chemicals, which can both damage the skin and absorb into the body (and are often environmentally harmful).

If you wouldn’t eat food containing these chemicals, you should think twice about using cosmetics that contain them. It’s hard to avoid every single potentially problematic chemical, but these are some of the worst offenders.

Parabens

Parabens are found in many different make-up products, as well as deodorant, lotion, shampoo, and shaving gel. Parabens mimic estrogen, and many studies have linked them to a range of health problems, including breast and skin cancer, decreased sperm count, and developmental disorders. Fortunately, even mainstream companies are now starting to make paraben-free versions of their shampoos and other products.

Formaldehyde

It probably won’t surprise you to hear that formaldehyde is harmful, but you may be surprised to find that it’s a common ingredient in products including eye shadow, cleanser, shampoo, conditioner, and nail polish. Formaldehyde is a carcinogen, so it seems like avoiding it should be a no-brainer.

Sodium Lauryl Sulfate (SLS)

SLSs are a surfactant, meaning they’re used to break up oils, and are found in many different types of beauty products, especially those that foam. They’re not only known to irritate the skin and eyes on their own, they can also interact with other chemicals to form carcinogens.

Coal Tar

Coal tar is a byproduct of coal processing and is used to create various ingredients that often appear in both hair dye and shampoo. It’s another carcinogen, and it’s banned in beauty products in Europe, which seems like a good reason to avoid it no matter what country you’re in.

Retinol Products

A variety of ingredients derived from retinol are used in moisturizer, sunscreen, and anti-aging products. However, while cosmetics containing retinol are probably safe to use at night, they become carcinogenic in sunlight, as crazy as that sounds. So they shouldn’t be used any time you’ll be out in the sun, and that means sunscreen containing retinol should definitely be avoided.

Oxybenzone

Oxybenzone is a common ingredient in sunscreen, although there’s increasing awareness about the damage it causes both to people who use it and to the environment. While it’s primarily known for causing coral bleaching in the ocean, it also acts like estrogen in the body and has been shown to affect sperm production. Fortunately, it’s getting much easier to find oxybenzone-free sunscreens.

Butylated Hydroxyanisole (BHA)

BHA is another (you guessed it!) carcinogen, and another ingredient that’s been banned in Europe but not in the U.S. It’s used primarily in perfume and in exfoliating products, but has been shown to interfere with the reproductive system and the endocrine system, including the thyroid. Before you buy new beauty products, take a look at the list of ingredients to make sure they don’t contain BHA or other harmful chemicals