Why are some perfumes called 'toilet water' and some called cologne or perfume?
While it may sound obvious to say the answer lies in the solution this is in fact true. It is the concentration of chemicals that create the fragrance suspended in an alcohol or alcohol and water based solution that defines the type of scent.
Commonly After Shave has the lowest concentration of aromatic compounds with a range of 1 to 3% being acceptable.
Eau de Cologne is next with an average of 5% concentration of citrus essence.
Eau de Toilette falls within the 5-15% range of concentrated aromatics
Eau de Parfum carries 15 to 20% concentration of fragnants and finally Parfum extract which must have a concentration of at least 20% but can go as high as 40%.
Because it is the concentration of aromatic compounds that dictate the type and not the actual ingredients, Eau de Toilette can describe either a male or female fragrance. According to the website, Most Expensive, the world's most expensive aftershave is the rather floral Eau de Toilette Amouage Die Pour Homme. The $250 price tag for a 1.7 oz bottle may have more to do with the vintage pink gold pointed bottle it comes in rather than the rarity or quality of the fragrance it contains.
Similarly the concentration of aromatic compounds also dictates the price. For example you might expect to pay between $62 to $110 for a 1.7 oz bottle of Coco Mademoiselle Eau de Parfum by Chanel while the Eau de Toilette version may cost as little as $50.
Many of the compounds used in the perfume industry are known allergens and can cause allergic reactions in the skin - eczema or spark asthmatic attacks.
The use of perfume is often found to cause skin allergies and of the 2,500 compounds commonly used in the perfume industry, 100 of them are known allergens. Because both perfume extract and eau de perfume contain the highest concentrations of these chemicals those who are sensitive to them may be better to use those products with the lowest concentrations: eau de toilette and eau de cologne. Even these would be better sprayed lightly on clothing rather than directly on the skin.
Interestingly according to the National Allergy Research Centre five relatively new fragrances which they ran tests on showed a far lighter use of those chemicals commonly used in perfumes which are known to cause allergies. This may indicate that those sensitive to the compounds found in the older more established fragrances would be better to try the lighter eau de toilette versions of the latest, modern perfumes.