Effectiveness of antiperspirants is generally based on the concentration (commonly called strength) of the principal active agent aluminium chloride. Today, the antiperspirant market offers hundreds of different products, each with diverging concentrations. Beyond that, most industrial made products do not provide any information about their strength. In 2009, the collaborative project www.wiki-products.org started an official compendium,
(listing + chart) but most manufacturers of antiperspirants did not reply to the official request. As a consequence of this, customers still do not know how much aluminium chloride many well-known and prominently advertised products contain.
Three examples for recipes and ingredients:
- Deodorant (often marketed as antiperspirant)
- approx. 1 % – 5 % aluminium chloride (AlCl3)
- emulsifiers (e.g. PEGs)
- skin care additives (e.g. parabens)
- alcohol denat.
- butan (as propellent)
- Industrially made antiperspirant
- approx. 5 % – 15 % aluminum chloride (AlCl3)
- citric acid
- tartaric acid
- hydrochloric acid
- glycerin (adhesive agent)
- calcium chloride
- sodium chloride
- Prescription strength antiperspirant
- approx. 15 % – 30 % aluminium hexahydrate (AlnCl[3n-m][OH]m) *
- Usnea barbata plant extracts (Old Man’s Beard)
- Eugenia caryophyllus plant extracts (clove, blossom)
- Salvia officinalis plant extracts (sage)
- alcohol denat.
fig. above | Only antiperspirants of the newest generation contain natural plant extracts which can prevent skin irritations. Recommended plant extracts are: sage (left); Usnea barbata (Old Man’s Beard, middle) and clove (right).
Expert’s Tip: To battle excessive sweating or Hyperhidrosis, persons concerned should always prefer prescription strength antiperspirants with a percentage of 20 % or higher.
People with sensitive skin should avoid products with various unacquainted ingredients. Customers should become aware of the fact that many industrially made antiperspirants contain a lot of substances which are therapeutically obsolete:
- colourants are added for the visual impression only
- perfumes will only mask body odour, they cannot prevent its forming
- conservatives simply allow fabrication and storage in very large numbers
- acids of any kind will irritate the skin, allergic reactions can occur
- disinfectants or germicides (e.g. triclosan) are controversial additives in cosmetics as they can destroy the natural bacterial flora of the skin
fig. above | Chemical structure of triclosan (polychloro phenoxy phenol). Several studies indicated that triclosan could alter the hormone regulation. It also contributes to making bacteria resistant to antibiotics. Still, though, the cosmetic industry use triclosan as a disinfectant in many products, for example in antiperspirants.
Of course, some ingredients, such as emulsifiers, are not avoidable as they make safe and (bio)compatible liquids possible.
Denatured alcohol, as a further example, has a bad reputation, but in association with antiperspirants it is the preferred medium for aluminium chloride. The aluminium salt is known for its strong chemical reactions with water by which hydrochloric acid and gas are formed. In some aqueous products (with water instead of alcohol, see example above) this reaction is slowed down by adding glycerin and/or cellulose. Nevertheless, condensate or sweat (by using roll-ons) could get into the antiperspirant bottle continuously until the reversal point is eventually reached. By that, the forming of irritating acids is just a question of time.
In general, customers should turn more attention on natural ingredients. Plant extracts and organic oils are the best choice for people with sensitive skin (especially women and children).
Raised suspicion: unacquainted ingredients
Parabens are the most widely used preservatives in cosmetic products. The most common parabens used in cosmetic products are methylparaben, propylparaben, and butylparaben.
A famous study published in 2004 (Darbre et al., Journal of Applied Toxicology) detected parabens in breast tumors. However, the study left several questions unanswered. For example, the study did not show that parabens cause cancer, or that they are harmful in any way, and the study did not look at possible paraben levels in normal tissue. In spite of that, a bustling unobjective discussion arose on the internet. Apprehensive people, mostly female customers who regularly were using cosmetics (approx. 50 % of which contain parabens), addressed the FDA (for example) and asked for an scientific evaluation of the risks.
The FDA is aware that estrogenic activity in the body is associated with certain forms of breast cancer. Although parabens can act similarly to estrogen, they have been shown to have much less estrogenic activity than the body’s naturally occurring estrogen. For example, a 1998 study (Routledge et al., in Toxicology and Applied Pharmacology) found that the most potent paraben tested in the study, butylparaben, showed from 10,000- to 100,000-fold less activity than naturally occurring estradiol (a form of estrogen). Further, parabens are used at very low levels in cosmetics. In a review of the estrogenic activity of parabens, (Golden et al., in Critical Reviews in Toxicology, 2005) the author concluded that based on maximum daily exposure estimates, it was implausible that parabens could increase the risk associated with exposure to estrogenic chemicals.
The FDA believes that at the present time there is no reason for consumers to be concerned about the use of cosmetics containing parabens. However, the agency will continue to evaluate new data in this area. If FDA determines that a health hazard exists, the agency will advise the industry and the public.
Expert’s tip: However, people who aren’t sure about the whole buzz should take a closer look at the label of their antiperspirant. There are several antiperspirants without parabens. Some products do not contain preservatives at all.
Triclosan is an ingredient added to many consumer products to reduce or prevent bacterial contamination (= disinfectant or germicide). It may be found in products such as clothing, kitchenware, furniture, and cosmetics, for example in antiperspirants/deodorants.
Several studies indicated that triclosan could alter the hormone regulation. It also contributes to making bacteria resistant to antibiotics – a serious problem for hospitals and clinics. Concerning the usage as a remedy for body odour in antiperspirants, triclosan has been accused to eliminate the complete bacterial flora of the skin – no matter if these germs are ‚good‘ or ‚bad‘ ones. Some germs, of course, are needful and important for healthy skin conditions.
Expert’s tip: Since triclosan became part of many health discussions a lot of cosmetic manufacturers have updated the recipes of their products, thus there a serveral antiperspirants avaiable that do not contain triclosan or other disinfectants.
Some products are sold as ‚alternative antiperspirants‘ that do not contain any aluminium salts. As an equivalent for the renowned AlCl3, an unknown and quite ominous ingredient named pentapeptide shall do the work of sweat reduction.
Peptides are short polymers of amino acids (a pentapeptide has 5 amino acids) linked by peptide bonds, but this is roughly all that customers might be able to find out. Pentapeptides originally were tested for regeneration of wounded skin, later they found their way into anti-wrinkle creams and related products. Anyhow, it was never explained how these polymers could work as anti-perspirantion agents. The FDA is still collecting scientific data, so there is no final conclusion if pentapeptides are hazardous for humans or not.
Expert’s tip: As long as there is no final evaluation or statement by the FDA people should avoid ‚revolutionary technologies‘. Still, over 97 % of all antiperspirants trust in the classic effect of AlCl3.
Nanoscale silver (nanoparticles)
Nanotechnology (the common short form is nanotech) is now used in the development and production of foods, color additives, dietary supplements, cosmetics, drugs and clothing fabrics. A nanometer is one-billionth of a meter, or one 25-millionth of an inch. A nanoparticle is defined as any molecular particle that is less than 100 nanometers in size.
Nanoparticles play a role in dozens of everyday products. Scientists estimate between 350 and 700 products manufactured in at least 17 different countries on the market employ nanotech. In cosmetical antiperspirants, nanoscaled silver (silver nanoparticles) is used for several reasons:
- Disinfectant: Silver, as a natural metal, has germicidal effects and kills many lower organisms effectively without harm to higher animals. For example, silver is capable of rendering stored drinking water potable for a long period of time. Many metallic surfaces of medical devices, refridgerators and washing machines are nowadays covered with a thin layer of nanosilver in order to prevent growth of bacteria. Fabrics of sportive clothing are often impregnated with silver nanoparticles for similar reasons (prevention of body odour). In antiperspirants, the same silver compounds shall reduce the development of BO as well.
- Conveyor: the nanosilver enables transdermal transport and resorption. By ’slipping‘ through cell membranes which are made from wider scaled molecules it allows ingredients of all kinds to sink into the dermis (transcellular osmosis). This could be an issue, as AlCl3 is not meant to enter the deeper parts of the skin.
- Cleaning agent: nanoscaled silver particles allow to create ‚clean‘ conditions on the skin. The microscopical rough surface of the spreaded particles has similar effects as the outer face of a lotus leave which easily rejects dirt and dust. This effect is known as lotus effect.
Nanoscale silver was introduced to the public as an innovative and spectacular technology which offers millions of chances. In no time, industry has avariciously adopted this invention to create endless variations. Today there are reams of products that use nanotech. A billion dollar business.
Ever since, critical observers said that the rampant use of nanoparticles came much too fast, without any regulation and previous research. As a matter of fact, there were no long-time studies, or official informations if these particles could be dangerous in any way. Not until much later, when a comparable discussion about hazardous diesel fine particles led to strict laws (regulated exhaust emissions), critics reminded the responsible authorities to re-examine nanotech.
photo above | Electron microscope image of nanoscale silver. Scientist are still not sure if nano particles could be hazardous to health and environment. What could happen if nanosilver pollutes the hydrologic circle? Will animals, for example fishes, develop cellular deformations?
The nanotech article on wikipedia.org quotes several recent studies concerning nanotoxicology, it says: „nanoparticles present possible dangers, both medically and environmentally. Most of these are due to the high surface to volume ratio, which can make the particles very reactive or catalytic. They are also able to pass through cell membranes in organisms, and their interactions with biological systems are relatively unknown.“ (complete article)