What's in fragrance?

A fragrance contains four basic ingredients:

• the “odorant” – the part that smells good (most fragrance is a mix of several odorants)
• the “fixative” – to make sure the smell doesn’t change over time
• a “solvent” – to dilute and blend the different odorants
• colouring and preservative - to prolong shelf life.

In modern perfumes virtually all these ingredients are made in the lab rather than derived from natural sources. Many of them mimic natural smells, but chemists have devised some good smells that have no natural counterpart.

Some of the ingredients are essential oils, derived from plants. Plants sometimes produce strong smells  to attract insects for pollination.  But some of those strong smells are insect-repellants or poisons, to discourage damage to the plant. So, although essential oils are "natural", they're not always harmless, even to humans.  

This section looks at ingredients in three ways:

• the full list of fragrance ingredients, from which a manufacturer chooses a particular combination
• a list of the most commonly used ingredients
• ingredients that are recognized by law as creating health problems in some people.