Many of these chemicals are commonly used in everyday products. Read labels and learn to recognize harmful ingredients. Keep this list handy as you shop online or in the store.
Endocrine Disrupters
Atrazine—This widely used herbicide has been found to turn male frogs into female frogs.1 It is pervasive in the water supply and has been linked to delayed puberty, prostate inflammation and breast cancer in animal studies.2 Research has found an association between atrazine and prostate cancer, but more study is necessary to make a direct connection.3,4
BPA—Bisphenol A, or BPA, is a chemical used in the production of plastic. It is found in water bottles, food-storage containers, toys, sippy cups, medical devices, and compact discs. BPA is also used as an epoxy resin to coat bottle tops, food cans, and water-supply pipes. BPA was invented as a medical estrogen, so its exposure is likely to affect hormonal homeostasis in humans. Studies have shown that BPA exposure leads to spikes in blood pressure and could cause obesity.5 BPA exposure has also been connected to increased cancer risk, brain damage, hormonal problems, and prostate gland issues in developing fetuses and children.5 Going “BPA-free” may not be a solution. Research shows BPS, the replacement chemical for BPA, has similar effects on the endocrine system.6
DDT—Di-chloro-diphenyl-trichloroethane was developed as a synthetic insecticide in the 1940s and was widely used to combat malaria and other insect-borne diseases in both civilian and military populations. Although DDT use in the United States has been limited since the 1970s, it continues to be used in countries where malaria risk is high. DDT is suspected to cause reproductive problems in humans and has been shown to cause liver tumors in animal studies.7,8
Dioxin—Dioxins are by-products of industrial processes such as chlorine bleaching of paper pulp, smelting, and the manufacture of certain herbicides. They are classified as persistent organic pollutants. Once they enter the body, mainly through meat, dairy products, fish, and shellfish, they can cause reproductive and developmental problems, damage to the immune system, hormone disruption, and cancer.9
Ethinyl Estradiol—The synthetic estrogen used in most oral contraceptive pills. Research arising from the Nurses’ Health Study found increased risk of breast cancer in women taking estrogen replacement therapy.10 Other studies have either found no connection between EE and breast cancer or were inconclusive.11
Fragrance/Parfum—Most of the thousands of chemicals listed as fragrances have not been tested for toxicity.12,13 Fragrances are found in everything from cosmetics and deodorants to laundry detergent, fabric softeners, and cleaning products.14
Organophosphates—OPs, created by the reaction between phosphoric acid and alcohol, were originally used as insecticides but were adapted as neurotoxins by the German military in World War II. Since then, they have been used under various brand names as ingredients in lawn and garden sprays. Although more research is required, these chemicals are potentially toxic for young children.15 Scientists continue to study the long-term effects of low-level exposure to organophosphates on human health.
Parabens—This class of commonly used preservatives help prevent bacterial growth in cosmetics, foods, and pharmaceutical products. They are added to toothpaste, shampoo, deodorant, and other products. A 2014 study found that parabens increased the growth of certain types of breast cancer cells, even at low levels of exposure.16
Perchlorate—This compound found in rocket fuel has been discovered as a contaminant in milk and produce. When it gets into the human body it disrupts thyroid function by competing with the nutrient iodine.17 Ingesting too much perchlorate can alter the hormone balance in your thyroid, which regulates metabolism and is critical for organ and brain development in infants and young children.17
Perfluorinated Chemicals—PFCs are used to make nonstick pans, waterproof clothes, and stain-resistant sofas and carpets. During cooking with PFC-coated cookware, the chemicals can escape into food and build up in the body. Research into the impact of PFCs on human health are ongoing, but animal and human studies have shown effects on developing fetuses and young children, decreased fertility, increased cholesterol, immune system effects, and increased cancer risk.18,19
Phthalates—Phthalates are a type of chemical that makes plastic both durable and flexible. They are found in products ranging from vinyl flooring and automobiles to rain jackets. Phthalates are also in personal care products such as nail polish, shampoo, soap, and hair spray. Researchers from the University of Michigan School of Public Health found in a 2014 study that exposure to phthalates in personal care products could lower testosterone levels, but more research on human health effects is needed.20
PBDEs—Polybrominated diethyl ethers are used as flame-retardants in everything from building materials and electronics to plastics, tiles, and foams. They have been connected to an assortment of health problems, including the disruption of thyroid function, learning impairment, delayed puberty onset, and fetal malformations.21,22 In animal research, exposure to low levels of PBDE has a greater impact on fetuses and infants compared to adults.23,24
Triclosan—An ingredient in many self-described antibacterial products, including hand sanitizers, deodorants and toothpaste. An animal study in 2014 found that triclosan interferes with a protein that helps flush chemicals out of the body, which over time might lead to liver cancer.25
Other Toxins to Avoid
Arsenic—Listed as a known human carcinogen by both the International Agency for Research on Cancer and the U.S. National Toxicology Program, arsenic is one of the world’s most toxic elements. While one hopes you won’t find it on any list of ingredients, it has historically been used in timber treatment and pesticides and is a by-product of coal-fired power plants, smelting, and mining. High levels of arsenic have also been found in deep-drilled wells.26
Coal Tar—Coal tar is a by-product of coke, a solid fuel composed of carbon and coal gas. Coal tar is used to make creosote, which is used as a preservative or antiseptic. According to the Centers for Disease Control and Prevention, coal tar creosote is the most widely used wood preservative in the United States. Coal tar products are used to treat skin diseases such as psoriasis and are used as animal repellents, as well as in insecticides, pesticides, fungicides, and animal dips (a chemical bath meant to protect animals, such as sheep or dogs, from parasites in their fur or on their skin). Occupational exposure to coal tar has been shown to increase the risk of skin, lung, bladder, kidney, and digestive tract cancers.26
DEA/TEA/MEA—Ethanolamine compounds are present in an assortment of personal care products, including shampoo, soap, hair dye, lotion, shaving cream, wax, eyeliner, mascara, blush, makeup foundation, and hair conditioner.27 The European Commission has banned DEA in cosmetics. Ethanolamine compounds have been linked to liver tumors.28
Ethoxylated surfactants and 1,4-Dioxane—This by-product results from using ethylene oxide, a known human carcinogen, to make other chemicals less harsh.29
Formaldehyde—Listed as a known human carcinogen, formaldehyde is used in the production of solvents, bonding agents, and adhesives. It is found in pressed wood such as plywood and particle board and in foam insulation. Long-term exposure to formaldehyde has been found to increase the risk of leukemia and brain cancer.26
Hydroquinone—This is found in skin-whitening and brightening compounds and is a potential carcinogen.30 Hydroquinone is a benzene derivative.
Lead—Exposure to lead has been linked to tumors of the kidney, brain, and lung.26 It can be present in old paint, which should be tested before it is sanded or removed. Lead can build up in the body over months and years. People are exposed to lead through paint, gasoline, solder, and consumer products in addition to food, air, water, and soil.
Mercury—A neurotoxin that impairs brain development and has been connected to autism, Alzheimer’s, ALS, and multiple sclerosis.31 Although mercury has not been directly connected to cancer, high doses have been found to harm multiple organs, including the immune system.31,32 Mercury is found in some types of eye drops and mascara.
Mineral Oil—This by-product of petroleum is found in styling gels, moisturizers, and baby oil. These oils are highly refined. Occupational exposure to less-refined mineral oils have been linked to skin cancer.33 While more refined liquids used in cosmetics have not been linked to cancer, they do create a film on the skin and prevent the release of toxins.
Oxybenzone—This organic compound, part of the benzophenone family, is included in many types of sunscreen, moisturizers, lip balms, anti-aging creams, conditioners, and lipstick. It has been linked to allergies, cell damage, and hormone disruption.34
Paraphenylenediamine (PPD)—This chemical substance is widely used in hair dye. Although PPD has not been directly linked to cancer, multiple studies in the past forty years have shown connections between long-term hair dye use and breast cancer.35
PCBs—Polychlorinated biphenyls are a group of chemicals used in everything from electrical equipment and flame-retardants to paints. Although the use of PCBs was restricted and banned in the 1970s and ’80s, the chemicals are persistent in the environment and remain present in the air, water, and soil. PCBs have been listed as a probable human carcinogen.26
Polyethylene Glycol (PEG)—These chemical compounds used in conditioners, cleansing agents, emulsifiers, and as surfactants often contain impurities, such as ethylene oxide and 1,4-dioxane, which are both recognized as human carcinogens.36–38
Silicone-Derived Emollients—These chemicals, which include dimethicone copolyol, cyclomethicone, and dimethicone, coat the skin and prevent it from breathing and releasing toxins. Some emollients have been associated with tumor growth and have been found to build up in the liver and lymph nodes.39
Sodium Lauryl Sulfate (or Sodium Lauryl Ether Sulfate)—This chemical is used to create foam in shampoos, toothpastes, conditioners, soaps, cosmetics and household cleaners. It has not been directly linked to cancer, but it has been found to cause skin and eye irritation.40
Talc—Talcum powder is made from talc and is widely used in baby powder, facial powders, and other consumer products. Multiple studies have looked at the connection between talcum powder applied to women’s genital area over time and ovarian cancer with mixed results.41
Toluene—This clear, colorless solvent occurs naturally in crude oil and is used to make fingernail polish, lacquers, adhesives, rubber, paints, and paint thinners. It is also added to gasoline to increase octane ratings. Toluene affects the nervous system, but it has not been found to cause cancer.42