The second in the ‘Everyday Compounds’ series looks at a chemical that the majority of us probably have sitting somewhere in our home. Aluminium chlorohydrate is the active ingredient in many antiperspirants, so how does it work – and why does a casual google search for it bring up a plethora of links with breast cancer?
Aluminium chlorohydrate (and other aluminium-based compounds that are sometimes employed instead) work as antiperspirants by temporarily ‘plugging’ sweat ducts, preventing the passage of sweat to the skin’s surface. The exact mechanism by which this occurs has been debated, but it’s generally agreed to be because the aluminium chlorohydrate can form a polymeric aluminium hydroxide-protein ‘plug’, which physically partially blocks perspiration from escaping the sweat glands. This plug slowly breaks down, which is why the effect of anti-perspirants isn’t permanent, and they have to be reapplied.
The concentration used in the majority of antiperspirants is in the range of 10-25% of whichever aluminium-based compound is being employed. If you’ve got a serious sweating problem, however, higher concentrations are available with a prescription.
Another use of aluminium chlorohydrate is as an anti-coagulant, or flocculating agent, in water and waste treatment. It acts to remove dissolved organic matter and small solid impurities, by causing them to aggregate together so they can be more easily removed.
Links with Cancer
Type aluminium chlorohydrate into a search engine, and amongst others, a number of results will appear seemingly linking aluminium chlorohydrate with breast cancer. Several loudly trumpet it as being a compound you should avoid in favour of ‘more natural’ alternatives – so, you’d presume they’ve got some pretty comprehensive research to hand as evidence for these strong-worded claims.
Of course not. To be fair, a number of them cite a study which does purport to show a link between aluminium-containing compounds and breast cancer; however, let’s look at this a little more closely. The study looks at aluminium levels in the breast of 17 breast cancer sufferers; they noted that aluminium levels were significantly raised in areas of the breast nearer the skin. So far, fair enough. However, they didn’t compare these levels to other areas in the body, nor to breast tissue in people not suffering from cancer. There was no comparison to what constitutes safe levels of aluminium within the body, and there’s some fantastic speculative language (lots of use of the word ‘potentially’) in their conclusion, where they link the aluminium levels to antiperspirants.
Additionally, another study examining the amount of aluminium absorbed from antiperspirants concluded that only 0.012% of the aluminium present is absorbed through the skin – that’s about 0.000004g per use. To put this in perspective, you’re absorbing more aluminium from your food in the same amount of time. As well as this, the limit for aluminium in bottled water is a lot higher, at 0.2mg per litre.
In conclusion – there is, currently, no scientific evidence definitively linking aluminium compounds in antiperspirants with cancer; more than that, there’s still no absolute evidence linking aluminium levels in tissue with cancer. There has been some research that shows the exposure of human breast cancer cells to 0.0001 mol/L solutions of aluminium compounds does result in increased migration and invasion of those cells; however, this was in a cell culture in a lab, and more research would be needed to confirm if the same is true within the human body. So, there’s no need to worry that you might be spraying cancer under your arms every morning.
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References & Further Reading
- Breast Cancer & Deodorants – The ‘No Links’ Effect – Cancer Research UK
- Dermal Absorption of Aluminium from Antiperspirants – R. Flarend et al
- Antiperspirants & Breast Cancer – National Cancer Institute
4 replies on “Everyday Compounds – Aluminium Chlorohydrate”
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Great post! If I had a dollar every time a customer ask me for a non-aluminium antiperspirant!
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This article misses several key scientific facts. The reality is that Al-containing cosmetics pose a significant risk, and an easily avoidable one.
The discussion about breast cancer risk here is a distraction; there is a stronger link with neurodegenerative diseases. Aluminium compounds (Al) have proven developmental and neurotoxicity, according to a 2014 study from the Bundesamt für Risikobewertung (BfR), a German governmental institution for risk assessment.
Al uptake through the skin is in fact very poorly studied. Flarend et al., 2001 is the only in vivo study so far, and has major limitations. We cannot rely on this data.
Any comparison of Al dermal absorption with food and water limits is utterly misleading without taking bioavailability into account. Oral bioavailability is only in the range of 0.1%.
The BfR (hardly a bunch of back-to-the-stoneage zealots) concluded that “…the tolerable weekly intake (TWI) of 1 milligramme of aluminium per kilogramme of bodyweight could be exhausted by single daily use of an aluminium-containing antiperspirant.” So just using an antiperspirant can deliver more Al into the body than is considered safe, and any Al from other cosmetics, food and water will come on top.