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The Dangers of Toothpaste and Deodorant

by Philippa Turnbull(more info)

listed in environmental, originally published in issue 103 - September 2004

Recent research and media coverage have caused a re-surfacing of concerns about a possible link between underarm deodorants and breast cancer. Many of us look at the ingredients on the food we buy, but few of us think to check what makes up our deodorant. Neither do we pay much attention to the contents of our toothpaste, even though this goes into our mouths and is usually swallowed by children when brushing their teeth. Meanwhile, we readily accept that skin patches, such as nicotine patches, work by absorption through the skin and that some medications, such as GKN spray, are applied under the tongue for maximum rapid absorption. Is it perhaps time for us to accept also that the ingredients of everyday products we apply to our skin or put into our mouths, pass into our bodies and are therefore likely to have some effect on us? Dr Samuel Epstein, co-author of The Safe Shoppers Bible says, "Since 1965 more than 4 million distinct chemical compounds have been reported in the scientific literature; of these, 70,000 are in commercial production and have been completely untested or inadequately tested, which raises questions about their safety.[1]

Here is an outline of the research suggesting negative health consequences from some ingredients used in everyday underarm deodorants and toothpastes.

Sodium Lauryl Sulphate

Sodium lauryl sulphate (SLS) is a detergent found in many foaming personal care products, including toothpastes. It is a major ingredient in many shampoos, shower gels and bubble baths. The reason SLS is so common is that it is inexpensive; just a small amount mixed with sodium produces plenty of foam. However, it is also highly corrosive. In the industrial world it is used for engine degreasing, garage floor cleaning, and in car wash soaps. Safe handling of the raw material, according to material safety data sheets, requires the wearing of self-contained breathing apparatus, heavy rubber gloves and safety goggles. The data sheet also states that it is irritating to mucous membranes and the upper respiratory tract.

Research into the use of SLS found compelling and alarming evidence indicating that SLS is rapidly taken up by eye tissue and retained, destroying delicate tissues there. Its uptake is greater in younger mammals.[2] It appears that it permanently impairs the normal functioning of eyes. The American Journal of Toxicology has found that SLS enters and maintains residual levels in the brain, liver, heart, and lungs from skin contact. It can also damage the immune system and cause severe inflammation of the skin. Another concern is its tendency to react with other ingredients as it can form carcinogenic nitrosamines by its interaction with other nitrogen-bearing ingredients within a formulation.[3]


Fluoride is normally added to toothpaste for the treatment of teeth to prevent decay. There is a large body of research indicating both that it is ineffective at preventing decay, and that it is harmful in several ways. So why is it used?

I have read two different accounts as to how fluoride came to be used and accepted as a preventative for tooth decay. One is that in 1945 a sales engineer at the biggest aluminium manufacturing plant in the United States realized that, during processing, thousands of tons of aluminium were going to waste. This waste is in the form of an extremely fine dust called aluminium filing tailings which are separated from the body of aluminium during processing. The manufacturers realized that if they could sell this waste, at even a minuscule price, it would reap a handsome profit. It had been discovered that the water in Hereford, Texas had a high content of natural fluorine, calcium fluoride in its natural state, produced by nature for thousands of years, which seemed to assist in making teeth strong. So, The Aluminium Trust decided arbitrarily to call the aluminium waste sodium fluoride and then attempt to induce all the cities in the US to add it to their municipal water supplies. The enthusiasm to find a tooth decay preventative resulted in logic and reason being overtaken by hasty, unsubstantiated tests, and claims based on these insufficient tests.

By whatever means that the connection between fluoride and the prevention of tooth decay was made, there is not one double-blind trial, after 50 years of use, that proves that fluoride reduces decay.[4]

The US Food and Drug Administration has insisted that the following warning appears on some tubes of toothpaste in America:

"Do not swallow. For children under 6 years old, to minimize swallowing use pea-sized amount. For children under 2, ask a dentist or physician. Warning: Keep out of the reach of children under 6. In case of accidental ingestion, seek professional assistance or contact a poison control centre immediately."

Reading this prompted me to do a rough calculation. My eldest child is heading towards five years old. Let us suppose that we have been brushing his teeth for four years. He has yet to successfully spit out any toothpaste whilst brushing. Now, let us estimate that you can fit 10 peas onto a 5ml teaspoon – a deliberately high estimate to be conservative. Using these figures, each time I brush his teeth, my son consumes 0.5ml toothpaste. Twice a day for four years, adds up to at least 1.5 litres of toothpaste that he has swallowed already.

So, in what ways can fluoride be harmful? The most life threatening health consequence of fluoride is cancer. Studies show bone cancer in young men has increased[5] and there is an overall increase in cancer of five per cent in water fluoridated areas, compared to non-fluoridated areas.[6] Dr Dean Burke, former chief scientist with the National Cancer Institute in the USA, testified before Congress that "Fluoride causes more human cancer deaths and causes it faster than any other chemical I have ever come across".

Scientists at the Food and Drug Administration (FDA) have reported a close inverse correlation between total fertility rates in women between ages of 10 and 49, and fluoride levels. This is consistent with their findings that fluoride adversely affects fertility in most animal species.[7] They also state that water fluoridation leads to neurological conditions in children. These are hyperactivity, attention deficit syndrome, reduced thyroid activity, increased aggression, increased lead in the brain and a significant reduction in IQ.

Hip fractures are also more prevalent in areas with fluoridated water. A study in France found 86 per cent more fractures than in non-fluoridated areas.[8] Drinking fluoridated water will double the number of hip fractures for both older men and women.[9],[10] Significantly, most of Europe has rejected artificial water fluoridation.

Fluorosis is the name for fluoride poisoning. Often it can be seen as blotches on children's teeth. There is no cure for this. In India, where the water is naturally fluoridated, 66 million people suffer from skeletal fluorosis, and many of these people are severely crippled as a result of it.

Fluoride is lethal at a dose of 5mg/kg body weight. It is also bioaccumulative. There is enough fluoride in one tube of toothpaste to kill anyone who weighs up to 30kg (approx 4.5 stone).


Parabens are a family of chemicals used in various personal care products. The family's common names follow the standard alkane hydrocarbon sequence: methyl paraben, ethyl paraben, propyl paraben, butyl paraben, etc. Their proper chemical name is alkyl-p-hydroxybenzoates (i.e. methyl-p-hydroxybenzoate, etc.) or para-hydroxybenzoic acids. They are used in many personal care products, including both deodorants and toothpastes, because they act as preservatives.

The US Environmental Protection Agency (EPA) reported that the chemical preservatives called parabens displayed oestrogenic activity in several tests.[11] Dr Elizabeth Smith has written that "It is a known medical fact that oestrogen stimulates breast cancer" and that "anything absorbed through the skin may be as high as 10 times the concentration of an oral dose." She also reported that, in one study, a paraben was injected under the skin and was found to have an "oestrogenic response on uterine tissues". Another pair of studies showed that propyl paraben and butyl paraben adversely affect male reproductive functions, and decrease daily sperm production.[12],[13] Meanwhile, men's sperm counts have fallen by almost a third since 1989.

The recently published study linking parabens and breast cancer was carried out at the University of Reading.[14] This specifically linked parabens from underarm deodorants to breast cancer, as the scientists discovered traces of paraben s in human breast tumour samples. The traces found were of a form of the chemicals that exists when it has passed through skin rather than entering the body via digestion. Ironically, it is this form that exists after absorption through the skin that is more strongly oestrogen-mimicking, as digestion partly breaks down the chemicals. The other piece of empirical evidence suggesting a link comes from Dr Philippa Darbre who led the research. She points out that there is a disproportionately high incidence of breast cancer in the upper outer quadrant of the breast – i.e. that section closest to the armpit and therefore to the area of skin where deodorant is applied. The proportion is 60 per cent in just one fifth of the breast. She also points out that the incidence of breast cancer has doubled in the last 20 years in England and Wales, in line with the increased use of underarm deodorants. There is also a growing incidence of breast cancer in men, seemingly in line with increased use of the products too.[14]

Another factor to consider is that many women shave their armpits, and then apply deodorant shortly afterwards. Shaving inevitably leads to small nicks and cuts through which substances can enter, even more readily than through intact skin. Of course, it is also possible that products used for shaving itself were the source of the parabens in the tumours, as shaving gels and liquid soaps/shower gels frequently contain them.

Researchers at the Fred Hutchinson Cancer Research Center in Seattle are carrying out an ongoing population-based, case-controlled study by questioning breast cancer patients and women without the disease about their deodorant use and shaving habits. Their published results indicate that cancer patients were more likely than the controls to use deodorants, and more likely to have applied it within an hour of shaving. The study has, however, also produced mostly contradictory results.[15] Meanwhile a further study examining breast cancer patients found that the more zealous the underarm regime of shaving and deodorant use, the younger the women were when diagnosed with cancer.[16]

Aluminium Chlorohydrate

Aluminium chlorohydrate is a common ingredient in deodorants because of its antiperspirant properties. It works by preventing the sweat glands from reacting to changes in body temperature, and by clogging the pores. The health concerns relating to aluminium chlorohydrate centre on its release of aluminium into the body. In 1995, a study by Laboratoire de Toxicologie et d'Hygiene Appliquee, Universite de Bordeaux suggested for the first time that aluminium is absorbed through the skin and that this has a greater effect on the body than does oral intake.[17]

Aluminium is very abundant in the earth and the sea but present only in small amounts in animal and plant tissues. Recent investigations implicate aluminium toxicity in Alzheimer's disease and other brain senility disorders.[18],[19] It is not clear how aluminium functions or interferes with the activities in the human body, but in Alzheimer's disease there are increased aluminium levels in the brain tissue. Also, areas with high amounts of aluminium in the drinking water – probably due to water treatment – are showing an increase in the incidence of Alzheimer's disease.[20] Aluminium is also implicated in hyperactivity and learning disorders in children.

The manufacturer's safety data sheet states "no toxicological data available" for aluminium chlorohydrate itself, indicating that its safety has not been tested.

Propylene Glycol

Propylene glycol appears as a major ingredient in many stick deodorants – including several 'natural' brands. It is also added to some toothpastes. The same product is found in most skin creams and lotions and baby wipes. It is inexpensive and it gives products a nice glide. In Industry it is used as antifreeze; it is used in aeroplanes and it is a brake and hydraulic fluid. The material safety data sheet warns the user to avoid skin contact and advises any person handling propylene glycol to wear a respirator, chemical safety goggles, rubber boots and heavy rubber gloves. The data sheet also links propylene glycol to contact dermatitis, kidney damage, liver abnormalities, rashes and dry skin, gastro-intestinal disturbances, nausea, headache, vomiting and central nervous system depression.

A published clinical review by the American Academy of Dermatology showed that propylene glycol causes a significant number of reactions and is a primary irritant to the skin even in low levels of concentration.[21]


1. Steinman D and Epstein S. The Safe Shoppers Bible. Macmillan. ISBN 002682685. 1995.
2. Clayton RM, Green K, Wilson M, Zehir A, Jack J, Searle L. The penetration of detergents into adult and infant eyes. Food Chem Toxicol. 23(2): 239-46. 1985.
3. Brant et al. The final report on the safety assessment of TEA, DEA, MEA. Journal of the American College of Toxicology. 2(7): 183-235.1983.
4. Dr Graeme Munro-Hall and Lilian Munro-Hall. The Hazards of Water Fluoridation. Positive Health. Issue 93. 2003.
5. Cohn Perry D. Ph.D. An Epidemiological Report on Drinking Water Fluoridation and Osteosarcoma in Young Males. New Jersey Department of Health, Environmental Health Service, Trenton NJ. November 8. 1992.
6. Yiamouyiannis JA and Dean Burk. Fluoridation and Cancer: Age Dependence of Cancer Mortality Related to Artificial Fluoridation. Fluoride. 10(3): 102-123. 1977.
7. Freni SC. Exposure to High Fluoride Concentrations in Drinking Water is Associated with Decreased Birth Rates. Journal of Toxicology and Environmental Health. 42: 109-121, 1994.
8. Jacqmin-Gadda H et al. Fluorine Concentrations in Drinking Water and Fractures in the Elderly. JAMA. 273(10): 1995.
9. Bordeaux Study. Hip Fracture rates related to Fluoridated water. JAMA. 264(4): 500-502 1990.
10. Robins JC and JL Ambrus. Studies on Osteoporosis IX. Effect of Fluoride on Steroid Induced Osteoporosis. Research Communications in Chemical Pathology and Pharmacology. 37(3): 453-461. 1982.
11. Daughton CG and Ternes TA. Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change? Environ Health Perspect. 107(6): 907-38. 1999.
12. Oishi S. Effects of propyl paraben on the male reproductive system. Food Chem Toxicol. 40(12): 1807-13. 2002.
13. Oishi S. Effects of butyl paraben on the male reproductive system in rats. Toxicol Ind Health. 17(1): 31-9. 2001.
14. Darbre PD, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope GS. Concentrations of parabens in human breast tumours. Journal of Applied Toxicology. 24(1): 5-13. 2004.
15. Mirick Dana K, Scott Davis, David B Thomas. Antiperspirant Use and the Risk of Breast Cancer. Journal of the National Cancer Institute. 94(20): 1578-1580. 2002.
16. McGrath Kris. An earlier age of breast cancer diagnosis related to more frequent use of antiperspirants/deodorants and underarm shaving. European Journal of Cancer Prevention. 12(6): 479-85. 2004
17. Anane R, Bonini M, Grafeille JM, Creppy EE. Bioaccumulation of water soluble aluminium chloride in the hippocampus after transdermal uptake in mice. Arch Toxicol. 69(8): 568-71. 1995.
18. Krishnan SS, McLachlan DR, Krishnan B, Fenton SS, Harrison JE. Aluminum toxicity to the brain. Sci Total Environ. 71(1): 59-64. 1988.
19. Graves et al. The Association between aluminium containing products and Alzheimer's Disease. Journal of Clinical Epidemiology. 43(1): 35-44. 1990.
20. Suay Llopis L, Ballester Diez F. Review of studies on exposure to aluminum and Alzheimer's disease. Rev Esp Salud Publica. 76(6): 645-58. 2002.
21. Joseph M et al. Propylene Glycol Dermatitis. Journal of The American Academy of Dermatology. 24: 90-95. 1991.


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About Philippa Turnbull

Philippa Turnbull is a Cambridge University graduate of Engineering who is now the Editor of the magazine Naturally Better for You, about natural products and where to buy them. Her aim through the magazine is to enable consumers to make informed decisions about the everyday products they buy. She can be contacted on

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