What are antiperspirants and deodorants?
Antiperspirants and deodorants are personal hygiene products designed to control sweating and body odour. Antiperspirants and deodorants contain ingredients that control sweat and body odour safely and effectively. They are readily available on the market as sprays (aerosol), sticks, creams or roll-ons.
differenceIs there a difference between an antiperspirant and a deodorant?1
The terms ‘antiperspirant’ and ‘deodorant’ are often used interchangeably but they do in fact refer to different products. Antiperspirants control sweat and body odour (B.O.) in two ways: firstly by preventing sweat reaching the skin surface and secondly by eliminating the bacteria that causes body odour via antimicrobial ingredients. Deodorants differ from antiperspirants as they only contain antimicrobial agents to prevent body odour; they do not control the flow of sweat. Both antiperspirants and deodorants often contain fragrances to help mask the smell of B.O.
How does an antiperspirant work?1
When an antiperspirant is applied to the skin surface, its active ingredients – usually aluminium salts – dissolve in the sweat or moisture on the skin surface of the armpit. The dissolved substance forms a gel, which creates a small temporary ‘plug’ near the top of the sweat gland, significantly reducing the amount of sweat that is secreted to the skin surface. Bathing and washing will remove the antiperspirant gel. Re-application of antiperspirants can be beneficial to help reduce sweating and keep fresh throughout the day. Antiperspirants reduce underarm sweating but they do not impact on the natural ability of the body to control its temperature (thermoregulation).
What ingredients are in antiperspirants and deodorants?
Antiperspirants and deodorants contain a number of ingredients to minimise sweating and help people feel fresh, cool and smelling good.
Alcohol is an ingredient present in some roll-ons, aerosols and gels. The active ingredients of antiperspirants and deodorants are often dissolved in alcohol because it dries quickly once applied to the skin and gives an immediate sense of coolness.
Aluminium salts are the active ingredient in antiperspirants. They work to reduce the flow of sweat from the sweat gland to the skin surface. Aerosol and roll-on products are likely to contain aluminium chlorohydrate, whereas sticks, gels and other solid products are most likely to contain an aluminium salt called aluminium zirconium. These salts provide a safe and effective means of controlling sweat.
Aluminium chloride is a strong aluminium salt used to treat people with mild to moderate hyperhidrosis or excessive sweating. Skin inflammation may occur as a side effect but this can be managed by following the product instructions carefully and using an emollient to protect the skin surface.2
The skin is home to natural bacteria that like to feed on sweat but as a result, produce bad smells. In occluded areas, such as the underarm, there are about 1 million bacteria per square centimetre. By lowering the number of bacteria on the skin, body odour can also be reduced. Antimicrobials agents kill bacteria and also slow their growth so that you stay odour-free for longer.
Aluminium salts present in antiperspirants are natural antimicrobial agents so they also kill bacteria on your skin. High efficacy deodorants without aluminium salts are available and rely on the use of specifically developed antimicrobial agents, such as triclosan or polyhexamethylene biguanide.
Alcohol is also effective at killing bacteria so deodorant and antiperspirant products that contain alcohol (or ethanol) are able to reduce body odour by combating the odour-forming bacteria.
Soap and water is not completely effective at killing and removing bacteria from the underarm, which is why many people use an antiperspirant or deodorant as part of their daily routine to control body odour and sweating.
- Fragrance and skin conditioners2
Perfumes and fragrances are used in most deodorants and antiperspirants in order to mask body odour and provide a feeling of freshness to the user. Virtually all antiperspirant and deodorant products contain some emollient oils to soothe and soften the skin. In roll-ons and sticks, the oils also provide a 'gliding' feeling as the product is applied.
The moisturisers used in antiperspirants are usually glycerin or vegetable derived oils, such as sunflower oil (helianthus annus). Most antiperspirants will also contain an oil to stop the product drying out into deposits, thus minimising product residue on skin and clothes. Silica, a natural mineral, is also used in antiperspirants and deodorants to absorb this oiliness so that the skin does not feel too greasy after application.
In order for antiperspirants to be effectively applied to the skin, they need to be held in some kind of carrying structure - whether that be the liquids used in aerosols or the solids used in sticks. Water is used in a range of antiperspirants as a carrier for other ingredients as it adds fluidity to roll-ons and creams and helps the product spread onto the skin. In aerosol products the active ingredients are held in a neutral liquid which enables them to be easily sprayed onto the skin. This liquid (commonly cyclomethicone) is often combined with a slightly denser mineral clay-like substance (disteardimonium hectorite) which provides structure to the antiperspirant and stops heavier ingredients sinking to the bottom.
Likewise, solid antiperspirant and deodorant products contain an agent which provides structure and prevents the ingredients from separating out. This structure can be provided by a combination of ingredients including hydrogenated castor oil, glycerol fats (triglycerides) and stearyl alcohol.
Some antiperspirant products also include an ingredient called PEG-8 distearate, which makes it easier to wash the product off in the bath or shower at the end of the day.
Parabens are a type of preservative found in many personal care products. The vast majority of antiperspirants and deodorants do not contain parabens because antiperspirants and deodorants are generally self-preserving.
Aerosol antiperspirants and deodorants are designed to work via a thin film which is propelled onto the skin. To create this film, products contain low, medium and high pressure propellants which produce a strong, but comfortable, spray to reach the skin. These propellants are commonly butane, isobutane and propane.References
- Unilever. Facts about Sweating
- Patient.co.uk. Excessive sweating. http://www.patient.co.uk/health/Excessive-Sweating.htm (Last accessed 15.12.12)