BEAUTY: Chemical reactions; The cocktail of chemicals that make up many beauty products can be lethal to our looks. So what can you do if you're the sensitive type?

Byline: EMMA BANNISTER

It's a harsh world out there and one that can be especially unkind to our hair, skin and nails.

Every day our skin is exposed to about six million different chemicals in the atmosphere. On top of that, we slap on products that contain a cocktail of additives, including artificial colours, fragrances, and formaldehyde.

As a result, it is estimated that between 50 and 90 per cent of us now have sensitive skin. And according to the Dermal Institute the demand for suitable beauty products has never been higher.

While environmental pollution is partly to blame, we should all take a long, hard look at the cosmetics and products we use, and start thinking about what we are putting on our bodies, day after day.

Here are M's top tips on what can be done to calm sensitive skin, teeth, nails and scalps...

Second skin

If your skin is occasionally red and irritated, try the following...

Stop using products with chemically-based ingredients. After exposure to the sun and smoking, an overly astringent cleanser is one of the main causes of damage to the skin.

Avoid creams that are prescribed for short-term use in salons which are too harsh to be used daily.

Switch to hypoallergenic products or ones that have a neutral pH level. The pH (Potential of Hydrogen) of a substance refers to

its degree of acidity or alkalinity and is measured on a scale of 0-14. Anything below seven is acidic and anything above is alkaline, meaning it will not disturb the natural barrier of your skin.

Fragrances, lanolin and alcohol make a product acidic. They cause gaps in the skin's natural barrier and lead to increased sensitivity and dehydration. This, in turn, leaves skin prone to invasion from bacteria and environmental harm. But products with a neutral pH will help to strengthen this barrier.

Teething problems

Your skin is not the only thing that can be on the sensitive side. If you've ever felt a sharp pain when biting into something cold, then you could have sensitive teeth.

If you suffer from this, Dr Mervyn Druian of the London Centre Of Cosmetic Dentistry has these tips:

Avoid very hot or very cold food and drink.

Don't be over-zealous with brushing as this can exacerbate gum nerve sensitivity. You only

need to remove very soft material from your teeth, so be gentle. Some electric toothbrushes now have indicators to tell you when you are brushing too hard.

Avoid acidic foods such as citrus fruits, tea and soda drinks as these can make the problem worse.

Use a toothpaste that contains strontium chloride. This crystallises the minerals in saliva and forces them into the pores of the roots to prevent cold or hot triggers aggravating exposed nerve-endings.

Hard as nails

Sadly, most of our favourite nail lengthening products contain lye, formaldehyde, toluol or toluene ingredients. These are not only harsh but possibly carcinogenic.

Over-use of these chemicals can cause the nail bed to become depleted of vital nutrients, making nails brittle. So lay off the acrylics and polish from time to time to give your nails a rest. And make sure you regularly moisturise and nourish your hands and nails.

Sensitive scalps

With the huge range of hair-styling products and gadgets around, it's no surprise that sensitive scalps are also more common. Paul Edmonds, of the Paul Edmonds Salon, advises:

Avoid overdosing on mousse, gel, hairspray and other products which block air and harbour the bacteria that causes a flaky scalp.

Use hair products that are rich in plant extracts.