Analysis of 20 breast tumours found high concentrations of para-hydroxybenzoic acids (parabens) in 18 samples. Parabens can mimic the hormone estrogen, which is known to play a role in the development of breast cancers. The preservatives are used in many cosmetics and some foods to increase their shelf-life.

"From this research it is not possible to say whether parabens actually caused these tumours, but they may certainly be associated with the overall rise in breast cancer cases," says Philip Harvey, an editor of the Journal of Applied Toxicology, which published the research.

"Given that breast cancer is the largest killer of women and a very high percentage of young women use underarm deodorants, I think we should be carrying out properly funded, further investigations into parabens and where they are found in the body," Harvey told New Scientist.

Chemical cousins

The new research was led by molecular biologist Philippa Darbre, at the University of Reading. She says that the ester-bearing form of parabens found in the tumours indicates it came from something applied to the skin, such as an underarm deodorant, cream or body spray. When parabens are eaten, they are metabolised and lose the ester group, making them less strongly estrogen-mimicking.

"One would expect tumours to occur evenly, with 20 per cent arising in each of the five areas of the breast," Darbre told New Scientist. "But these results help explain why up to 60 per cent of all breast tumours are found in just one-fifth of the breast - the upper-outer quadrant, nearest the underarm."

However, Chris Flower, director general of the Cosmetic, Toiletry and Perfumery Association, challenged the study's findings. "There are almost no deodorants and body sprays that contain parabens," he says. "Although they are in most other creams and cosmetics, the safety margin is huge and they would not have any effect on enhancing growth of new tumours."

Darbre replies that deodorants and antiperspirants have only stopped containing parabens in the last few months and that the tumours she studied occurred prior to this.

A small survey by New Scientist of three British high street shops and one supermarket found deodorants in each that contained parabens, although most of these products did not. However, many other products used under the arm commonly contained parabens, such as body sprays, hair removal creams and shaving gels. Body lotions, face creams, cleansers and shampoos also frequently contained parabens.

Skin deep

Previously published studies have shown that parabens are able to be absorbed through the skin and to bind to the body's estrogen-receptors, where they can encourage breast cancer cell growth.

But Flower maintains that the amount of parabens absorbed by the skin is very low and the parabens are "metabolised by the skin cells to produce products that have no estrogenic activity".

Darbre's research did not look at the concentrations of parabens in other areas of the breast or body tissues and Harvey cautions that the significance of the chemicals in tumour tissue should not be over-interpreted.

Darbre says she has not used cosmetic products, including underarm deodorants, for eight years. She recommends that other women do the same "until their safety can be established".

Journal reference: Journal of Applied Toxicology (vol 24, p5)

carcinogenic contaminant of cosmetic products. Almost 50% of cosmetics containing ethoxylated surfactants were found to contain dioxane. See Ethoxylated surfactants From Material Safety Data Sheet (MSDS): 1,4-Dioxane may exert its effects through inhalation, skin absorption and ingestion 1,4-Dioxane is listed as a carcinogen. Effects of overexposure: 1,4-dioxane is an eye and mucous membrane irritant, primary skin irritant, central nervous system depressant, nephrotoxin, and hepatotoxin. Acute exposure causes irritation, headache, dizziness, and narcosis. Chronic inhalation exposure can produce damage to the liver and kidneys, and blood disorders. Medical condition aggravated by exposure preclude from exposure those individuals with disease of the blood, liver kidneys, central nervous system, and those susceptible to dermatitis 2-bromo-2-nitropropane-1,3-diol (Bronopol) Toxic, causes allergic contact dermatitis. See Nitrosating agents Alcohol, Isopropyl (SD-40) A very drying and irritating solvent and dehydrator that strips your skin's natural acid mantle, making us more vulnerable to bacteria, moulds and viruses. It is made from propylene, a petroleum derivative. It may promote brown spots and premature aging of skin. Ammonium Laureth Sulfate (ALES) See Anionic Surfactants, Sodium Laureth Sulfate and Nitrosating Agents Ammonium Lauryl Sulfate (ALS) See Anionic Surfactants, Sodium Laureth Sulfate and Nitrosating Agents Anionic Surfactants Anionic refers to the negative charge these surfactants have. They may be contaminated with nitrosamines, which are carcinogenic. Surfactants can pose serious health threats. They are used in car washes, as garage floor cleaners and engine degreasers - and in 90% of personal-care products that foam. They are also known as: Sodium Lauryl Sulfate (SLS) Sodium Laureth Sulfate (SLES) Ammonium Lauryl Sulfate (ALS) Ammonium Laureth Sulfate (ALES) Sodium Methyl Cocoyl Taurate Sodium Lauroyl Sarcosinate Sodium Cocoyl Sarcosinate Potassium Coco Hydrolysed Collagen TEA (Triethanolamine) Lauryl Sulfate TEA (Triethanolamine) Laureth Sulfate Lauryl or Cocoyl Sarcosine Disodium Oleamide Sulfosuccinate Disodium Laureth Sulfosuccinate Disodium Dioctyl Sulfosuccinate etc Benzalkonium Chloride Highly toxic, primary skin irritant. See Cationic surfactants From Material Safety Data Sheet (MSDS): Material is highly toxic via oral route. Effects of overexposure: mists can cause irritation to the skin, eyes, nose, throat and mucous membranes. Avoid direct contact. Symptoms: muscular paralysis, low blood pressure, cns depression and weakness. Emergency and first aid procedures: Eyes - corrosive! Immediately wash eyes with plenty of water. Inhalation - remove person to fresh air. Give oxygen (if breathing is difficult). Call physician. Ingestion - if conscious, immediately drink large quantities of fluid to dilute and induce vomiting. Call physician. Butylated Hudroxyanisole (BHA) Causes allergic contact dermatitis. Butylated Hydroxytoluene (BHT) Causes allergic contact dermatitis. Contains toluene. See Toluene Cationic surfactants These chemicals have a positive electrical charge. They contain a quaternary ammonium group and are often called "quats". These are used in hair conditioners, but originated from the paper and fabric industries as softeners and anti-static agents. In the long run they cause the hair to become dry and brittle. They are synthetic, irritating, allergenic and toxic, and oral intake of them can be lethal. Stearalkonium chloride Benzalkonium chloride Cetrimonium chloride Cetalkonium chloride Lauryl dimonium hydrolysed collagen Cetalkonium chloride See Cationic surfactants Cetrimonium chloride See Cationic surfactants Chloromethylisothiazolinone  and Isothiazolinone Causes contact dermatitis From Material Safety Data Sheet (MSDS): Eye contact - corrosive to the eyes with possible permanent damage. Skin contact - corrosive to the skin, possibly resulting in third degree burns. Can be harmful if absorbed. Can cause allergic contact dermatitis in susceptible individuals. Ingestion - can be fatal. Inhalation - can be corrosive to the mucous membranes and the lungs. Can cause an allergic reaction in susceptible individuals. Cocoamidopropyl Betaine From Material Safety Data Sheet (MSDS): Can cause eye and skin irritation. Cocoyl Sarcosine See Nitrosating agents Cyclomethicone See Silicone derived emollients DEA (diethanolamine), MEA (Monoethanolamine), & TEA (triethanolamine) Often used in cosmetics to adjust the pH, and used with many fatty acids to convert acid to salt (stearate), which then becomes the base for a cleanser. TEA causes allergic reactions including eye problems, dryness of hair and skin, and could be toxic if absorbed into the body over a long period of time. These chemicals are already restricted in Europe due to known carcinogenic effects. Dr. Samuel Epstein (Professor of Environmental Health at the University of Illinois) says that repeated skin applications . . . of DEA-based detergents resulted in a major increase in the incidence of liver and kidney cancer. See Nitrosating agents From Material Safety Data Sheet (MSDS): Health Hazard Acute And Chronic: Product is severely irritating to body tissues and possibly corrosive to the eyes. Explanation Carcinogenicity: Amines react with nitrosating agents to form nitrosamines, which are carcinogenic. Diazolidinyl urea Established as a primary cause of contact dermatitis (American Academy of Dermatology). Contains formaldehyde, a carcinogenic chemical, is toxic by inhalation, a strong irritant, and causes contact dermatitis. See Formaldehyde From Material Safety Data Sheet (MSDS): Causes severe eye irritation. May cause skin irritation. Signs and symptoms of exposure Symptoms of inhalation: if misted, will cause irritation of mucous membranes, nose, eyes and throat. Coughing, difficulty in breathing. Symptoms of skin contact: contact causes smarting and burning sensations, inflammation, burns, painful blisters. Profound damage to tissue. Symptoms of eye contact: will cause painful burning or stinging of eyes and lids, watering of eyes, and inflammation of conjunctiva. Dimethicone See Silicone derived emollients Dimethicone Copolyol See Silicone derived emollients Disodium Dioctyl Sulfosuccinate See Anionic surfactants Disodium Laureth Sulfosuccinate See Anionic surfactants and See Ethoxylated surfactants Disodium Oleamide Sulfosuccinate See Anionic Surfactants DMDM Hydantoin Contains formaldehyde. See Formaldehyde Ethoxylated surfactants Ethoxylated surfactants are widely used in cosmetics as foaming agents, emulsifiers and humectants. As part of the manufacturing process the toxic chemical 1,4-dioxane, a potent carcinogen, is generated. On the label, they are identified by the prefix "PEG", "polyethylene", "polyethylene glycol", "polyoxyethylene", "-eth-", or "-oxynol-".  See 1,4-Dioxane FD&C Colour Pigments Synthetic colours made from coal tar. Contain heavy metal salts that deposit toxins onto the skin, causing skin sensitivity and irritation. Animal studies have shown almost all of them to be carcinogenic. Formaldehyde Formaldehyde is a known carcinogen (causes cancer). Causes allergic, irritant and contact dermatitis, headaches and chronic fatigue. The vapour is extremely irritating to the eyes, nose and throat (mucous membranes). See Nitrosating agents Fragrance Fragrance on a label can indicate the presence of up to four thousand separate ingredients, many toxic or carcinogenic. Symptoms reported to the USA FDA include headaches, dizziness, allergic rashes, skin discoloration, violent coughing and vomiting, and skin irritation. Clinical observation proves fragrances can affect the central nervous system, causing depression, hyperactivity, and irritability. Hydrolysed Animal Protein See Nitrosating agents Imidazolidinyl urea The trade name for this chemical is Germall 115. Releases formaldehyde, a carcinogenic chemical, into cosmetics at over 10°C. Toxic. See Formaldehyde Imidazolidinyl Urea See Nitrosating agents Lanolin Any chemicals used on sheep will contaminate the lanolin obtained from the wool. The majority of lanolin used in cosmetics is highly contaminated with chlorinated organo pesticides like DDT. Lauryl dimonium hydrolysed collagen See Cationic surfactants Lauryl or Cocoyl Sarcosine See Anionic Surfactants Lauryl Sarcosine See Nitrosating agents Liquidum Paraffinum Liquidum Paraffinum is an exotic sounding way to say mineral oil (!!) See Mineral Oil MEA compounds See Nitrosating agents Methylisothiazolinone and Methylchloroisothiazolinone Both cause cosmetic allergies Mineral Oil Petroleum by-product that coats the skin like plastic, clogging the pores. Interferes with skin's ability to eliminate toxins, promoting acne and other disorders. Slows down skin function and cell development, resulting in premature aging. Used in many products (baby oil is 100% mineral oil!) Any mineral oil derivative can be contaminated with cancer causing PAH's (Polycyclic Aromatic Hydrocarbons). Manufacturers use petrolatum because it is unbelievably cheap. Mineral oil Liquidum paraffinum (also known as posh mineral oil!) Paraffin oil Paraffin wax Petrolatum Nitrosating Agents The following chemicals can cause nitrosamine contamination, which have been determined to form cancer in laboratory animals. There are wide and repeated concerns in the USA and Europe about the contamination of cosmetics products with nitrosamines. 2-bromo-2-nitropropane-1,3-diol Cocoyl Sarcosine DEA compounds Imidazolidinyl Urea Formaldehyde Hydrolysed Animal Protein Lauryl Sarcosine MEA compounds Quaternium-7, 15, 31, 60, etc Sodium Lauryl Sulfate Ammonium Lauryl Sulfate Sodium Laureth Sulfate Ammonium Laureth Sulfate Sodium Methyl Cocoyl Taurate TEA compounds Paraben preservatives (methyl, propyl, butyl, and ethyl) Used as inhibitors of microbial growth and to extend shelf life of products. Widely used even though they are known to be toxic. Have caused many allergic reactions and skin rashes. Highly toxic. From Material Safety Data Sheet (MSDS): Emergency overview: Warning! Harmful if swallowed or inhaled. Causes irritation to skin, eyes and respiratory tract. May cause allergic skin reaction. Skin contact: Causes irritation to skin. Symptoms include redness, itching, and pain. May cause allergic skin reactions. Eye contact: Causes irritation, redness, and pain. Paraffin wax/oil Paraffin Wax is mineral oil wax. See Mineral Oil Polyethylene Glycol (PEG) compounds Potentially carcinogenic petroleum ingredient that can alter and reduce the skin's natural moisture factor. This could increase the appearance of aging and leave you more vulnerable to bacteria. Used in cleansers to dissolve oil and grease. It adjusts the melting point and thickens products. Also used in caustic spray-on oven cleaners. See Ethoxylated surfactants Potassium Coco Hydrolysed Collagen See Anionic Surfactants Propylene/Butylene Glycol Propylene glycol (PG) is a petroleum derivative. It penetrates the skin and can weaken protein and cellular structure. Commonly used to make extracts from herbs. PG is strong enough to remove barnacles from boats! The EPA considers PG so toxic that it requires workers to wear protective gloves, clothing and goggles and to dispose of any PG solutions by burying them in the ground. Because PG penetrates the skin so quickly, the EPA warns against skin contact to prevent consequences such as brain, liver, and kidney abnormalities. But there isn't even a warning label on products such as stick deodorants, where the concentration is greater than in most industrial applications. From Material Safety Data Sheet (MSDS): Health Hazard Acute And Chronic Inhalation: May cause respiratory and throat Irritation, central nervous system depression, blood and kidney disorders. May cause Nystagmus, Lymphocytosis. Skin: Irritation and dermatitis, absorption. Eyes: Irritation and conjunctivitis. Ingestion: Pulmonary oedema, brain damage, hypoglycaemia, intravascular hemolysis. Death may occur. PVP/VA Copolymer A petroleum-derived chemical used in hairsprays, wavesets and other cosmetics. It can be considered toxic, since particles may contribute to foreign bodies in the lungs of sensitive persons. Quaternium-7, 15, 31, 60, etc Toxic, causes skin rashes and allergic reactions. See Nitrosating agents From Material Safety Data Sheet (MSDS): Skin: Prolonged or repeated exposure may cause skin irritation. May cause more severe response if skin is damp. May be a weak skin sensitizer in susceptible individuals at greater than 1% in aqueous solution. Rancid Natural Emollients Natural oils used in cosmetics should be cold pressed. The refined vegetable oils found on supermarket shelves and many health food stores which lack colour, odour and taste are devoid of nutrients, essential fatty acids, vitamins and unsaponifiables - all valuable skin conditioning agents! They also contain poisonous "trans" fatty acids as a result of the refining process. Another important factor to consider with creams made from plant oil is the use-by date. The most beneficial plant oils (like rosehip, borage and evening primrose oils) are polyunsaturated, which means they oxidise and go rancid fairly quickly (about 6 months). Most off-the-shelf cosmetics have a shelf life of three years. Rancid oils are harmful, they form free-radicals, which damage and age your skin. Silicone derived emollients Silicone emollients are occlusive - that is they coat the skin, trapping anything beneath it, and do not allow the skin to breathe (much like plastic wrap would do.) Recent studies have indicated that prolonged exposure of the skin to sweat, by occlusion, causes skin irritation. Some synthetic emollients are known tumour promoters and accumulate in the liver and lymph nodes. They are also non-biodegradable, causing negative environmental impact. Dimethicone Dimethicone Copolyol Cyclomethicone Sodium Cocoyl Sarcosinate See Anionic Surfactants Sodium Laureth Sulfate (SLES) Ammonium Laureth Sulfate (ALES) When combined with other chemicals, SLES and ALES can create nitrosamines, a potent class of carcinogens. It is frequently disguised in semi-natural cosmetics with the explanation "comes from coconut". See Anionic Surfactants, See Ethoxylated surfactants and See Nitrosating agents From Material Safety Data Sheet (MSDS): Warning! Causes skin and eye irritation! Avoid contact with eyes, skin and clothing. The material was classified as a moderate to severe eye irritant. Sodium Lauroyl Sarcosinate See Anionic Surfactants Sodium Lauryl Sulfate (SLS) Ammonium Lauryl Sulfate (ALS) Used in car washes, garage floor cleaners and engine degreasers - and in 90% of products that foam. Animals exposed to SLS and ALS experience eye damage, central nervous system depression, laboured breathing, diarrhoea, severe skin irritation, and even death. Young eyes may not develop properly if exposed to SLS and ALS because proteins are dissolved. SLS and ALS may also damage the skin's immune system by causing layers to separate and inflame. It is frequently disguised in semi-natural cosmetics with the explanation "comes from coconut". See Nitrosating agents and See Anionic Surfactants From Material Safety Data Sheet (MSDS): ·         Eye Contact: Instillation of a 29% sodium lauryl sulfate solution into the eyes of six albino rabbits produced severe irritation. The material was classified as a severe skin irritant. Sodium Methyl Cocoyl Taurate See Nitrosating agents and See Anionic Surfactants Stearalkonium Chloride A chemical used in hair conditioners and creams. Causes allergic reactions. Stearalkonium chloride was developed by the fabric industry as a fabric softener, and is a lot cheaper and easier to use in hair conditioning formulas than proteins or herbals, which do help hair health. Toxic. See Cationic surfactants Talc Scientific studies have shown that routine application of talcum powder in the genital area is associated with a three-to-fourfold increase in the development of ovarian cancer. TEA (Triethanolamine) Laureth Sulfate Synthetic emulsifier. Highly acidic. Over 40% of cosmetics containing Triethanolamine (TEA), have been found to be contaminated with nitrosamines, which are potent carcinogens. See Anionic Surfactants and See Nitrosating agents From Material Safety Data Sheet: Special Hazard Precautions: Product is severely irritating to body tissues and possibly corrosive to the eyes. Handle with care. Avoid eye & skin contact. Avoid breathing vapors if generated. If there is danger of eye contact, wear a face shield. Explanation Carcinogenicity: Amines react with nitrosating agents to form nitrosoamines, which are carcinogenic. TEA compounds See Nitrosating agents Toluene From Material Safety Data Sheet (MSDS): Poison! Danger! Harmful or fatal if swallowed. Harmful if inhaled or absorbed through skin. Vapor harmful. Flammable liquid and vapor. May affect liver, kidneys, blood system, or central nervous system. Causes irritation to skin, eyes and respiratory tract. Inhalation: inhalation may cause irritation of the upper respiratory tract. Symptoms of overexposure may include fatigue, confusion, headache, dizziness and drowsiness. Peculiar skin sensations (e. G. Pins and needles) or numbness may be produced. Very high concentrations may cause unconsciousness and death. Ingestion: swallowing may cause abdominal spasms and other symptoms that parallel over-exposure from inhalation. Aspiration of material into the lungs can cause chemical pneumonitis, which may be fatal. Skin contact: causes irritation. May be absorbed through skin. Eye contact: causes severe eye irritation with redness and pain. Chronic exposure: reports of chronic poisoning describe anemia, decreased blood cell count and bone marrow hypoplasia. Liver and kidney damage may occur. Repeated or prolonged contact has a defatting action, causing drying, redness, and dermatitis. Exposure to toluene may affect the developing foetus.