Cosmetics have been around for a long time. More than 4,000 years ago, ancient Egyptians had a variety of beauty aids, including body oils, face creams, perfumes, eye makeup, face paint, hair dyes, and lipstick. Women in ancient Greece applied a white powder to lighten their skin and used powdered charcoal as eye shadow.

These days cosmetics are big business, the worldwide annual expenditures for cosmetics is estimated at U.S. $18 billion. The cosmetic industry is also big science. Most cosmetics contain a combination of at least some of the following ingredients: water, emulsifier, preservative, thickener, colour, fragrance and pH stabilisers.

As an example of some of the science in cosmetics, emulsions are small droplets of oil dispersed in water or small droplets of water dispersed in oil. Since oil and water don’t mix, emulsifiers are added to produce the small droplets and to prevent the oil and water from separating. Emulsifiers work by changing the surface tension between the water and the oil, thus producing a product with an even texture.I’m not a huge fan of heaps of make-up, especially when people go overboard. Anyway, to learn more go here or here.