• Kayıt
Merhaba sayın ziyaretçimiz; sayfamıza hoşgeldiniz. Sayfamıza üyelik gerekmeksizin soruları görüntüleyebilirsiniz ve yine soru sormak, cevap yazmak, yorum yapmak ve oylamaya katılmak için ise hızlı ve çok kolay ve ücretsiz bir şekilde üyelik işlemlerinizi gerçekleştirebilirsiniz. Sizi de paylaşım kervanımızda aramızda görmek için sabırsızlanıyoruz.

İlgili sorular

0 oy
0 cevap 12 kez görüntülendi
12 kez görüntülendi 27, Temmuz, 2022 Bilgisayar Ağları kategorisinde xz4523we (120 puan) tarafından soruldu
0 oy
0 cevap 37 kez görüntülendi
37 kez görüntülendi 26, Nisan, 2022 Bilgisayar Ağları kategorisinde xe4523mk (120 puan) tarafından soruldu
0 oy
0 cevap 23 kez görüntülendi
23 kez görüntülendi 11, Mart, 2022 Bilgisayar Ağları kategorisinde nnm5633m (120 puan) tarafından soruldu
0 oy
0 cevap 40 kez görüntülendi
40 kez görüntülendi 24, Şubat, 2022 Bilgisayar Ağları kategorisinde ggh5633h (120 puan) tarafından soruldu
0 oy
0 cevap 16 kez görüntülendi
16 kez görüntülendi 26, Eylül, 2021 Bilgisayar Ağları kategorisinde yyjfi1566s (300 puan) tarafından soruldu

En popüler etiketler

8,391 soru

122 cevap

4 yorum

2,849,569 kullanıcı

Hoş geldiniz, Netyuvam S&C sizelere sorularınızın diğer kullanıcılarımız tarafından cevaplanması için bir ortam sağlar.

The chemistry of cosmetics

0 oy
16 kez görüntülendi

Cosmetics materials are not a modern invention. Humans have used various substances to alter their appearance or accentuate their features for at least 10,000 years, and possibly a lot longer.  

 

Women in Ancient Egypt used kohl, a substance containing powdered galena (lead sulphide—PbS) to darken their eyelids, and Cleopatra is said to have bathed in milk to whiten and soften her skin. By 3000 B.C men and women in China had begun to stain their fingernails with colours according to their social class, while Greek women used poisonous lead carbonate (PbCO3) to achieve a pale complexion. Clays were ground into pastes for cosmetic use in traditional African societies and indigenous Australians still use a wide range of crushed rocks and minerals to create body paint for ceremonies and initiations.

 

Today, cosmetics are big business. According to the 2011 Household Expenditure Survey, conducted every five years by the Australian Bureau of Statistics, Australians spend around $4.5 billion on toiletries and cosmetic products every year. Cosmetic advertising, previously directed mainly at women, is now targeting a wider audience than ever.

 

What is a cosmetic?

In Australia, a cosmetic is defined under the Industrial Chemical (Notification and Assessment) Act 1989 as ‘a substance or preparation intended for placement in contact with any external part of the human body' (this includes the mouth and teeth). We use cosmetics to cleanse, perfume, protect and change the appearance of our bodies or to alter its odours. In contrast, products that claim to ‘modify a bodily process or prevent, diagnose, cure or alleviate any disease, ailment or defect’ are called therapeutics. This distinction means that shampoos and deodorants are placed in the cosmetics category, whilst anti-dandruff shampoos and antiperspirants are considered to be therapeutics.

 

Regulation and safety

In Australia, the importation, manufacture and use of chemicals—including those used in cosmetics—are regulated by the Australian Government’s National Industrial Chemicals Notification and Assessment Scheme (NICNAS). NICNAS works to ensure that chemicals used in consumer products do not cause significant harm to users or to the environment.

 

In the case of cosmetics, every ingredient contained within the product must be scientifically assessed and approved by NICNAS before being manufactured or imported into Australia and before they can be used in consumer products. Where appropriate, NICNAS sets limits on the level at which a chemical can be used in a product and also conducts reviews on chemicals when new evidence arises.

 

Cosmetic products that make an additional therapeutic claim (such as moisturisers that also lighten the skin) are regulated by a different organisation—the Therapeutic Goods Administration (TGA).

 

Cosmetics and other personal care items must also be labelled in accordance with the Trade Practices (Consumer Product Information Standards, Cosmetics) Regulations 1991. This regulation requires that all intentionally added ingredients are listed on the product label, and is enforced by the Australian Competition and Consumer Commission (ACCC).

 

What do cosmetics contain?

There are thousands of different cosmetic products on the market, all with differing combinations of ingredients. In the United States alone there are approximately 12,500 unique chemical ingredients approved for use in the manufacture of personal care products.

 

A typical product will contain anything from 15–50 ingredients. Considering the average woman uses between 9 and 15 personal care products per day, researchers have estimated that, when combined with the addition of perfumes, women place around 515 individual chemicals on their skin each day through cosmetic use.

 

But what exactly are we putting on our skin? What do those long names on the ingredient list mean and what do they do? While the formula of each product differs slightly, most cosmetics contain a combination of at least some of the following core ingredients: water, emulsifier, preservative, thickener, emollient, colour, flavors and fragrances and pH stabilisers.

 

3, Eylül, 2021 Bilgisayar Ağları kategorisinde aafjij156s (300 puan) tarafından soruldu

Bu soruya cevap vermek için lütfen giriş yapınız veya kayıt olunuz.

...

A Question2Answer database query failed when generating this page.

A full description of the failure is available in the web server's error log file.