Ingredients to Avoid in Cosmetics and Personal Care Products
Broad Ingredient Categories
Sunscreen Ingredients to AVOID
Patti and Tamey's Top Six
Ingredients to Avoid in Household Products

Ingredients to Avoid in Cosmetics and Personal Care Products

To pull together a list of ingredients that are questionable for use in our everyday products, we turned to the experts. Lucky for us consumers, there are several consumer health and environmental advocacy groups that have been paying attention to this sort of thing for a long time.

The Pure Know How list is a composite from the many lists produced by these organizations - so you won't have to! Check out their resources and website listed in our Reference Links section. Stay tuned - we'll have a pocket sized list you can order soon.

Look out for these individual chemical ingredients
 

Acetone
Used in nail polish remover and finishes. It can cause peeling and splitting of nails, skin rashes and nail brittleness. Inhalation may irritate the lungs and in large amounts it is narcotic, causing symptoms of drunkenness similar to ethanol. The FDA proposed a ban in astringent.

Alpha Hydroxyl Acids (AHA) and Beta Hydroxy Acids ( BHA)
Skin peeling products, mainly face, body creams and lotions, are designed to diminish wrinkles and blemishes by stripping off the outer layer of skin to produce a smoother finish. They penetrate the skin and can cause adverse skin reactions. May increase sensitivity to sunlight, therefore increase photo-aging and risk of sun-related skin cancers.

Aluminum Chlorohydrate
Most frequently used antiperspirants; it acts by altering the pH level of the skin on which it is applied, thereby retarding the flow of perspiration. Causes occasional infections of hair follicles, skin irritation and allergic reactions.

Benzoyl Peroxide
A bleaching and drying ingredient in cosmetics. A skin allergen, irritant and toxic by inhalation. Canada does not permit in cosmetics intended to be applied to the skin but it is permitted in artificial nail kits. On Canadian Hotlist and rated as a high hazard by the Skin Deep Cosmetic database.

Bisphenol A (BPA)
BPA is used to make polycarbonate plastics and epoxy resins and thus is found in variety of consumer products including baby bottles, nail polish, and lining of tin cans, plastic food containers and electronic appliances. They are linked to the affecting the reproductive system, endocrine disruption and accumulating in the body without breaking down.

Bronopol (2-brono-2-nitropropane-1-3)
Used as a preservative in cosmetics, especially shampoos, creams, lotions, rinses, bat products and eye make-up, as it inhibits bacteria, fungi and yeasts. It can form nitrosamine - which has been determined to form cancer in lab animals and also break down into formaldehyde. The Consumer Dictionary of Cosmetic Ingredients advises “if a product lists an ingredient with bronopol and another compound ending with “amine” or “amide”, don't purchase it.

Butylated hydroxytoluene (BHT)
BHT's are preservatives and antioxidants in cosmetics, foods and beverages. Can cause allergic reactions and contact dermatitis. Contains toluene which is a neurotoxin, endocrine disruptor, and may promote toxicity in organ system (non-reproductive).

Camphor
Used in emollient creams, preshave lotions, after shave lotions and skin fresheners and perfumes as a preservative and to give a cool feeling to the skin. Local irritant which may cause contact dermatitis and is a central nervous system stimulant. It is readily absorbed through body tissues and can irritate eyes, nose, and throat can prompt dizziness, confusion nausea. Avoid inhaling vapors. On the Health Canada Cosmetic Ingredient Hot List.

Coal-Tar and Coal Tar Derivatives
Coal tar appears in many hair dyes and strong dandruff and psoriasis shampoos, but the FDA failed to ban it even though studies have linked it to cancer. Coal-tar chemicals are found in many "FD&C" or "D&C" colours used in makeup and hair dye. FD&C Blue 1 and FD&C Green 3 are possible carcinogenic, and impurities in other colours -- D&C Red 33, FD&C Yellow 5 and FD&C Yellow 6 -- have been shown to cause cancer when applied to the skin. Coal tar derivatives are used as a dye base for dark hair colouring. Coal tar is a known human carcinogen and some substances derived from it that are used in hair colouring have been linked to bladder cancer and non-Hodgkin's' lymphoma. See Colourants 101.

Cyclopentasiloxane
A widely used silicone in hair and skin conditioners and also in deodarants, suntan gels, and cosmetics. Suspected as an endocrine disrupter.

Dibutyl-phthalate (DBP) is of particular concern because documented exposures are high and its health effects are potentially very serious. In nail polish and mascara, DBP helps thin films stay flexible, reducing brittleness and cracking. Animal studies show that DBP causes birth defects and harm to male reproductive organs. Timing of exposure was critical: Harm was done to animals exposed in the womb or shortly after birth. A 2002 Environmental Working Group (EWG) report found DBP in 37 nail products from 22 different companies. Their 2002 report, "Not Too Pretty" found phthalates in 52 of 72 different personal-care products.

Dimethylphthalate (DMP) and diethylphthalate (DEP) are two other commonly used phthalates which are used to make scents last longer.

Diethanolamine (DEA)
Diethanolamine (DEA), triethanolamine (TEA), and monoethanolamine (MEA) are widely used in shampoos, lotions and creams as a skin softener and thickener and is readily absorbed into the skin. DEA is a strongly suspected as being a human carcinogen. These chemicals are also known to combine with nitrates to form cancer-causing nitrosamines - compounds shown to cause cancer in laboratory animals. If a product contains nitrites (used as a preservative or present as a contaminant not listed on labels) a chemical reaction can occur either during manufacturing or after a product is made.

There is no way to know which products contain nitrosamines because government does not require manufacturers to disclose this information on the label. A 1997 study by the U.S. National Toxicology Program found that these compounds themselves might also be carcinogenic. Repeated skin application of DEA was found to cause liver and kidney damage in animals. The study also discovered that when absorbed through the skin, DEA accumulated in organs. TEA may also cause contact dermatitis in some individuals.

Dimethicone
A silicone oil used as a skin protectant. Used to coat the skin, trapping anything beneath it and does not allow the skin to breathe. Recent studies have indicated that prolonged exposure of the skin to sweat, by a barrier, causes skin irritation.

Ethanol (Rubbing alcohol)
An antibacterial used in mouthwashes, nail enamel, astringents, perfumes and many other cosmetic products. Avoid inhalation, as may cause drowsiness, impaired vision and stupor.

Formaldehyde
Found in eye shadows, mascaras, other cosmetics, and in high percentages (up to 10%) in nail hardeners, it is widely used as a preservative, germicide and fungicide. It has recently been reclassified by the International Agency for Research on Cancer to its highest toxic class as a "known human carcinogen". May be listed on labels as formalin or methyl aldehyde, but is also hidden in many chemical combinations. It can cause allergic reactions, headaches, and chronic fatigue.

In its liquid state, formaldehyde, present in the ingredients DMDM hydantoin, diazolidinyl urea, and quaternium-15, can be absorbed through the skin and nails. As a volatile organic compound, or VOC, formaldehyde evaporates when the product is wet; levels drop sharply once it's dry. Consumer concern has led many manufacturers to remove it from their nail polishes. Quaternium-15 causes more dermatitis complaints than any other preservative, according to the American Academy of Dermatology. Bronopol, often listed as 2-bromo-2-nitropropane-1, 3-diol, can contribute to the formation of cancer-causing nitrosamines, according to the FDA. It can also break down to produce formaldehyde.

Glycol Ethers
Widely used industrial solvents found in nail polish, deodorant, perfumes and other cosmetics, some glycol ethers are hazardous to the reproductive system. Other effects of overexposure include anemia and irritation of the skin, eyes, nose and throat. Avoid those listed on labels as EGPE, EGME, EGEE, DEGBE, PGME, DPGME and those with "methyl" in their names.

Hydrogenated Cottonseed Oil
Contamination of oil during production includes contact with pesticides, PCBS and other organic matter like mercury, arsenic, and lead.

Isopropyl Alcohol
Also known as rubbing alcohol. Used in many cosmetic products including make-up, shampoos, and moisture lotions as an antibacterial, solvent and denaturant. It is prepared from propylene, which is obtained in the cracking of petroleum. Drying to the skin especially in higher concentrations.

Lead
Lead is a known carcinogen and hormone disruptor. It is readily absorbed through the skin, and accumulates in the bones. It causes neurological damage and behaviour abnormalities, and large accumulations can result in leg cramps, muscle weakness, numbness and depression. Lead is found in some hair dyes.

Lead Acetate
Used primarily by men to disguise their grey hair in men's hair colouring is banned in Canada and Europe because it is suspected carcinogen and reproductive toxin. It is listed on Health Canada's Cosmetic Ingredient Hotlist "based on data indicating skin absorption and possible links to carcinogenicity and reproductive toxicity." Canadian products must be free of the chemical by the end of 2006.
The Skin Deep cosmetic safety database rates this ingredient a very high hazard at 10/10.

Methylene Chloride

Used in nail enamels and cleansers. It is a skin irritant and can be absorbed through the skin and converted to carbon monoxide. The FDA has banned its use in cosmetics “because of its animal carcinogenicity and likely a hazard to human health”. Not permitted in aerosols in Canada and is on the Canadian Hotlist.

Monoethanolamine (MEA)
Moderate skin and severe eye irritant. Unsafe in products left on skin and not rinsed off. MEA is a sensitizer and can instigate immune system response that can include itching, burning, scaling, hives and blistering of skin. Nitrosamines, a known carcinogen, can form in all cosmetic ingredients containing "amines" and amino derivatives with nitrogen compounds. See also Diethanolamine (DEA) and Triethanolamine (TEA).

Mineral Oil
Widely used on baby creams and lotions, cleansing/moisturizing and eye creams hair products and make-up. A liquid mixture of liquid hydrocarbons obtained from petroleum. Interferes with skin's ability to breathe, slows down skin function and cell development. Can cause allergic reactions, dryness and clog pores. Also known as paraffin oil, paraffin wax, and petrolatum.

Nylon
Used as a fiber in eyelash lengtheners and mascara and as a molding compound to shape cosmetics. A petroleum-based product that can cause allergic reactions.

Parabens
Methyl-, propyl-, ethyl- and butylparaben are used as inhibitors of microbial growth and to extend shelf life of products and are the most common preservatives used in cosmetics. It is estimated that 75-90% of cosmetics contain parabens. Parabens are easily absorbed through the skin. Parabens are a common allergen - causing allergic reactions and skin rashes. Parabens are also known endocrine disruptors, as they mimic the female hormone estrogen. Meaning they bind to estrogen receptors in women and could potentially affect estrogen-sensitive functions of the body. Parabens are linked to the development of breast cancer. The cumulative effect of parabens combined with other hormone disrupting chemicals affect our bodies is a noted concern.

Petrolatum (vaseline, petroleum jelly)
Commonly used in cold creams, conditioning creams, eye pencils and shadows, baby products and lipsticks (used as a lubricant in lipsticks for smooth application and shine). Provides a barrier on the skin which can protect the skin from irritation but also prevents the skin from taking in oxygen and respiring out waste. Petrolatum can cause allergic reactions in sensitive individuals. It is a purified mixture of semisolid hydrocarbons from petroleum – a reported cancer causing ingredients. Its use depletes a non-renewable resource. Prohibited for use in cosmetics in the European Union.

p-Phenylenediamine (PPD) - 4-MMPD and 4-MMPD Sulphate
Found in most commercial permanent hair dyes, PPD is linked with skin irritations, eczema, and respiratory disorders. It can react with other chemicals to cause photosensitivity. PPD is mutagenic (capable of altering DNA codes, a precursor to cancers) and reasonably anticipated to be a human carcinogen. Also called oxidation dyes, amino dyes, para dyes, or peroxide dyes. It has been banned in Europe. The US Food and Drug Administration proposed legislation would require warning labels on products, advising that this ingredient can penetrate skin and has been determined to cause cancer in lab animals. Health Canada considers hair dye made with PPD to be safe and is an acceptable ingredient when used correctly, in products that do not come in contact with skin for a long period of time. Health Canada strongly advises a "patch test" for hair dye. The Skin Deep cosmetic safety database rates this ingredient a very high hazard at 10/10 and is also listed on their dirty dozen (ingredients to avoid list).

Phthalates
Phthalates are chemical plasticizers and are used widely in fragrances, deodorants, nail polishes, hair products and lotions. The oily texture of phthalates acts like a moisturizer and helps lotions penetrate skin. Phthalates are also used to enhance fragrances, as solvents, and to denature alcohol. These endocrine-disrupting chemicals are suspected of contaminating breast milk and causing damage to the kidneys, liver, lungs and reproductive organs. A study published in Environmental Health Perspectives (December 2002) found that DEP is damaging to the DNA of sperm in adult men at current levels of exposure. DNA damage to sperm can lead to infertility and may also be linked to miscarriages, birth defects, infertility and cancer in offspring. Other medical literature links them to various reproductive defects in developing male fetuses (when mother is exposed during pregnancy), as well as early puberty in girls. Since, phthalates often "hide" behind the term "fragrance" choose products labeled "fragrance-free" or that are scented exclusively with pure botanical or essential oils.

Phthalates are also present in, and can evaporate from, soft vinyl (PVC) toys, flooring and other products, which should be avoided. For more information, search for "phthalates" at www.thegreenguide.com.

For an in-depth report on phthalates read Not Too Pretty - Phthalates, Beauty Products and the FDA by the US-based Environmental Working Group.

Polyethylene and Polyethylene glycol (PEG ingredients)
Found in many personal care products like hand lotions, hair colourings, suntan products, deodorants, baby-care products and make-up. This synthetic chemical is used as a binder, plasticizing ingredient, solvent and softener for cream bases. Improves resistance to moisture and oxidation. PEG compounds are safe in themselves but should not be used on damaged skin. They can be contaminated with 1,4- dioxane, a suspected carcinogen, which produced liver cancer in rodents in National Cancer Institute (NCI) studies and are under review by the Cosmetic Ingredient Panel in the US.

Propylene Glycol
A humectant, or moisture-attracting ingredient, found in mascara, lotions, creams and other cosmetics, can irritate skin in sensitive individuals. Ideally, this is a vegetable glycerin mixed with grain alcohol, both of which are natural. Often it is a synthetic petro-chemical mix used as a humectant (because it is cheaper and more readily absorbed through the skin). It has been known to cause allergic and toxic reactions when used in high percentages, and is recognized as a neurotoxin by the National Institute for Occupational Health and Safety in the U.S.

Quaternarium-15
Widely used in shampoos and other hair products, face and body lotions bath products, makeup, cleansers as well as suntan preparations as an anti-microbial ingredient that is active against bacteria. It is a formaldehyde releaser and is the number one cause of dermatitis from preservatives according to the American Academy of Dermatology’s Testing Tray results. It is toxic, avoid.

Resorcinol
A preservative used in hair dyes, lipstick and other hair tonics. Irritating to the skin and mucous membrancs and may cause allergic reaction. The FDA issued a notice in 1992 that it has not been shown to be safe as stated for over-the-counter prodcuts, The Cosmetic Ingreent Review Panel concluded that is safe as a cosmetic ingredient. The EU is currently looking at the data. The Skin Deep cosmetic safety database rates this ingredient high hazard - an 8/10.

Salicylic Acid
Used as a preservative and antimicrobial in externally products used as an antiseptic ingredient and fungicide. It is used as a keratolytic drug applied topically to treat acne to slough skin. Also being widely promoted in anti-aging beta hydroxide products. It can be absorbed through the skin and is a penetration enhancer whereby it alters skin structure to allow other chemicals to penetrate deeper into the skin. The EU has banned it for children under 3 years except in shampoos and it is noted on Canada’s Hot list as restricted for concentrations equal to or less than 2%. Cosmetic Ingredient Review Assessments found it safe for use in cosmetics when it is formulated to avoid irritation and when formulated to avoid increasing sun sensitivity or when directions for use include daily use of sun protection.

Sodium Lauryl Sulfate - Sodium Laureth Sulfate (SLS)
SLS's are synthetic surfactants or surface acting agents, used as a detergent and for their sud/foam-building abilities. It is present in ninety per cent of commercial shampoos, as well as skin creams and some brands of toothpaste. This chemical can cause eye irritations, skin rashes, hair loss, scalp scurf similar to dandruff, and enhances allergic response to other toxins and allergens. The U.S. government has warned manufacturers of unacceptable levels of dioxin formation in some products containing this ingredient. The chemical can react with other ingredients to form cancer-causing nitrosamines. Sodium laureth sulfate may be contaminated with 1,4-dioxane, a carcinogen. Dioxane readily penetrates the skin. While dioxane can be removed from products easily and economically by vacuum stripping during the manufacturing process, there is no way to determine which products have undergone this process. Labels are not required to list this information. The Cosmetics Ingredient Review (CIR), a panel of cosmetics-industry experts established to safety-test ingredients (cir-safety.org), reported that SLS also causes "severe epidermal changes" to mouse skin, a finding that "indicates a need for tumor-enhancing activity assays." This year, after review of over 250 existing SLS studies, the CIR concluded that SLS is not cancer-causing. However, Samuel Epstein, M.D., author of the Safe Shopper's Bible, says he is not convinced and recommends avoiding SLS.

Toluene
This solvent is found in nail products and is obtained from petroleum or by distilling Tolu balsam. Also known as methylbenzene. Overexposure may cause fatigue, confusion, headache, dizziness, or numbness. Can cause liver damage and is irritating to the skin, respiratory tract, central nervous system and kidneys.

Triclosan (Trilocarban)
A very strong antibacterial preservative used in many personal care products and it highly absorptive. It is used in deodorant, antibacterial soap and other cosmetic and household products. Its deodorant properties are due to the inhibition of bacterial growth. Triclosan is also bio-accumulative - it builds up in fatty tissue and can't be broken down properly. Linked to a range of health and environmental effects: Health - skin irritation, allergic reactions, antibiotic and bacterial resistance, can also form the probable human carcinogen chloroform when exposed to chlorinated water and dioxins may be formed when it is manufactured or exposed to sunlight and Environmental - commonly found contaminate in water and found in concentrated levels in fish. Also been shown to feminize fish. Dioxins, which are linked to cancer. Triclosan is listed as a pesticide by the US Environmental Protection Agency and is on Health Canada Cosmetic Ingredient Hot List.

Antibacterial compounds, like triclosan, provide no additional benefit beyond those of plain soap. Numerous studies have found that washing with regular soap and warm water is just as effective at killing germs.

Triethanolamine (TEA)
Commonly used in personal care and cosmetics products to adjust the pH balance or formulation. Eye and skin irritant. Best suited for products that do not have prolonged contact with skin, with concentration not exceeding 5% and that are intended to "rinse off". May contain nitrosamines, a known carcinogen, as a by-product of manufacturing and which readily penetrate the skin. See also Diethanolamine (DEA) and monoethanolamine (MEA).

Broad Ingredient Categories
 

Antibacterials
Found in cleansers, deodorants and other cosmetic products, antibacterial agents such as triclosan and triclocarban are designed to kill germs. Over 75% of liquid and 29% of bar soaps are labeled anti-bacterial.

Anti-bacterial products have been shown to promote the growth of antibiotic-resistant bacteria in laboratory settings according to a study in the April 1999 Journal of Biological Chemistry and the July 13 2000 Nature. This is disputed by the Soap and Detergent Association. Recent publication in Aquatic Toxicology found triclosan to be harmful in the development of frogs and potentially humans, where it disrupted thyroid function in frogs.

The Canadian Paediatric Society called for parents to stop buying antibacterial products, and instead use soap and water to wash toys, hands or household items.

Synthetic Colours - FD&C, D&C colours, Coal Tar Colours
A colour additive is any dye, pigment or substance that can impart colour when added or applied to a food, drug, cosmetic or to the human body. Used extensively in personal care products, certified FD&C colours are derived primarily from petroleum and are sometimes known as "coal-tar dyes" or "synthetic-organic" colours. They will be labeled as FD&C or D&C, followed by a colour and a number. Example: FD&C Red No. 6 / D&C Green No. 6. Certifiable colour additives are used widely because their colouring ability is more intense than most colours derived from natural products and are more stable, provide better colour uniformity and blend together easily to provide a wide range of hues.
Synthetic colours may contain heavy metal salts that may leave toxic by-products on the skin. They are a contributor to skin irritations and contact dermatitis. Many synthetic colours are believed to be cancer-causing agents and have been found to cause cancer in animals - although these are related to very high concentrations over long periods of use.
Look for these worrying "coal-tar" dyes: FD&C Blue 1 and FD &C Green 3 are carcinogenic, D&C Red 33, FD&C Yellow 5 and FD&C Yellow 6 impurities have been shown to cause cancer when applied to the skin. Colour additives that are exempt from certification are obtained primarily from mineral, plant, or animal sources.
See Colourants 101.

Synthetic Fragrances
Synthetic fragrance is the most common ingredient found in personal care products. Many synthetic fragrances used in cosmetics can have as many as 200 ingredients. There is no way to know what the chemicals are, since on the label it will simply say "Fragrance." Some of the problems caused by these chemicals are headaches, dizziness, rash, hyperpigmentation, violent coughing, vomiting, and skin irritation. Fragrance is a known trigger of asthma. Take a look at our e-bulletin "Get a whiff of this" and also see what effects fragrance may have on our bodies and environment.

Sunscreen Ingredients to AVOID

Sunscreens identify active ingredients to filter UVA and/or UVA radiation: some use synthetic chemicals to absorb UVA/UVB radiation, some mineral-based filters to physically block UVA/UVB radiation and others use both. When considering what ingredients you would most like to avoid in sunscreen – you need to look at your activities and your preferences (if your comfortable with chemicals being absorbed into your skin or lying on top of skin) and what effects some ingredients may have (known to cause rashes or skin irritation, chemicals that may disrupt your hormones) Our list of common sunscreen and sun block ingredients to use with caution:

Avobenzone (also called Parsol 1789)
Effectively blocks long-wave UVA radiation but not UVB. Usually combined with other sunscreen chemicals to produce a "broad-spectrum" product. Avobenzone is easily absorbed through the epidermis and is still a chemical that absorbs ultraviolet radiation energy. Since it cannot destroy this energy, it has to convert the light energy into chemical energy, which is normally released as free radicals. In sunlight, avobenzone degrades and becomes ineffective within about 1 hour.

In January 2007, the FDA approved a new sunscreen called Mexoryl SX, or ecamsule, for use in the U.S. Hailed by dermatologists as a highly effective UV-A barrier, the only product in which it is currently used is L'Oreal's Anthelios SX. However, to make the sunscreen a broad-spectrum UV-A and UV-B protector, avobenzone was added, which, as previously stated, may damage DNA.

Benzophenone (benzophenone-3)
Common in chemical sunscreens as it blocks both types of harmful UV radiation. Reported skin irritation and allergic reactions. "Photo contact dermatitis is common on areas of the face and neck where sunscreen has been applied and is most often noticed after UV exposure because UV light activates the sunscreen,"

Recent research has shown estrogenic activity in lab tests. Scientists discovered that benzophonones, one of the five of six chemicals commonly used in chemical sunscreens studied, seemed to mimic estrogen and recommended more studies to look at possible long-term effects as a hormone disruptor. The estrogen-like qualities of benzophenone are of particular concern in light of studies showing that, to a greater extent than other sunscreen ingredients, benzophenone is readily absorbed by the skin. Other researchers report "The studies saying that some of these compounds have estrogenic effects are all very preliminary. No one has ever linked any sunscreen to any disease related to estrogen in actual people, so at this point; it's premature to get worried."

Homosalate & Octy-methoxycinnamate (octinoxate)
Common sunscreen ingredients. Concern because they have shown estrogenic activity in lab tests - disrupting hormones, affecting development of the brain (particularly the hypothalamo-pituitary-gonadal system) and reproductive organs in laboratory rats. Needs more research on toxic effects.

Padimate-O
A derivative of the once-popular PABA sunscreen ingredient. This one has mixed research results as far as we can find. Some say Padimate-O is "excited" by the UV energy which they absorb and become reactive, acquiring the potential to attack cellular components, including DNA." These studies to date have been laboratory based and were not done in living animals or humans. So based on this result – it has been on noted as a ingredient to use with caution.

But at the same time, it is an ingredient found in some of these “better” and “best” recommended sunscreens. What's a consumer to do? We looked at what we are using the product for and for how long and make an assessment. There are sunscreens that don't have Padimate-O and other good products that do. Sorry guys - you'll have to choose for yourself on this one!

See Skin Deep assessment of Padimate O and a list of sunscreen spf 15 and above that contain this ingredient.

PABA – (para-aminobenz acid)
Though rarely used now in sunscreens, be aware of products that contain the ingredient. Forty percent of the population is sensitive to it, experiencing red, itchy skin.

Titanium dioxide (TiO2)
A common active ingredient in physical sunscreens. TiO2 has shown phototoxicity - the capability to damage skin upon exposure to light. Research supports Ti02 use in sunscreen as safe, based on what is known so far. "Titanium dioxide itself is an effective sunscreen and does not show phototoxicity in a normal condition as a sunscreen. A protective action of TiO2 for UV light may be much greater than its phototoxic effect on human skin." Most titanium dioxide used in sunscreens is coated with materials that reduce its photoactivity. Current evidence shows titanium dioxide is much less likely than other chemical sunscreens to penetrate human skin.

Nanoparticles
Physical sunblocks, made with the minerals titanium dioxide (Ti02) or zinc oxide (ZO), stay on skin's surface, reflecting UV rays. However, to make them more aesthetically appealing and less opaque, some newer products use Ti02 reduced to microscopic nanoparticles . A nanometer (nm) is about a billionth of a meter-a unit so small that a single human hair is about 80,000 nm in diameter. The nanoparticles are unpredictable - they could penetrate the skin, enter the bloodstream, where they may damage cells. Some tests link Ti02 to DNA damage. The consensus in the scientific community, as demonstrated by a 2006 Australian government literature review on the topic, is that neither TiO2 nor ZO penetrate the skin deep enough to actually enter the bloodstream.

Other
In addition to some of the active UV-protective substances in sunscreen, there are other ingredients to check your sunscreen for - see our Ingredients to Avoid list. We know this can be overwhelming - pick 1-2 at a time. For example:

Parabens (butyl-, ethyl-, methyl-, and propyl-) are preservatives widely used in cosmetic products that might, like benzophenone, mimic estrogen. Virtually all sunscreens contain parabens, so avoiding takes some savvy label reading. See Face it.

Synthetic fragrances are in most sunscreens and are unregulated and unlabeled, may aggravate allergies or asthma. See Get a whiff of this.

List of References

Beauty to Die For - The Cosmetic Consequences, Judi Vance.2000.
The CancerSmart Consumer Guide, Labour Environmental Alliance Society, 2006.
Concentrations of parabens in human breast tumours, Journal of Applied Toxicology, 2004.
A Consumer's Dictionary of Cosmetic Ingredients, Ruth Winter, 2005
Dirty Dozen SSC: The Dirty Dozen Ingredients in Personal Care Products, The Green Guide. Feb.2004.
The Good, The Bad & The Ugly, The Green Guide. Feb. 2003
Guide to Less Toxic Products, Environmental Health Association of Nova Scotia, 2004.
The Safe Shopper's Bible - A Consumer's Guide to Nontoxic Household Products, Cosmetics and Food, David Steinman & Samuel S. Epstein, M.D. 1995.
Women and their Toxic World, Women in Europe for a Common Future, 2006
Contact Dermatitis: Sometimes It's In Your Face, American Academy of Dermatology, 2004.
Endocrine (Hormonal) Disrupters in Cosmetics and Toiletries , Prevent Cancer Coalition, retrieved from website June 20, 2007.
Quote from Dr. Martin Weinstock, M.D., Ph.D., a professor of dermatology and community health at Brown University in Rhode Island and chair of the American Cancer Association's skin cancer advisory group
In Vitro and in Vivo Estrogenicity of UV Screens , Dr. Margret Schlumpf. Environmental Health Perspective. March 2001
A Review of the Scientific Literature on the Safety of Nanoparticulate Titanium Dioxide or Zinc Oxide in Sunscreens , Department of Health and Ageing, Therapeutic Goods Administration. Australian Government, (2006).
U. S. Food and Drug Administration. "Color Additives Fact Sheet." Fact Sheet, Center for Food Safety and Applied Nutrition, Office of Cosmetics and Colors, July 30, 2001.