Naturally-occurring chemicals

Last update 17 August 2017

Many cosmetics contain chemicals derived from natural sources such as plants and minerals. These cosmetics are often marketed as 'natural', 'organic' or 'pure'.

Not all chemicals from natural sources meet the definition of a 'naturally-occurring chemical' in the Industrial Chemicals (Notification and Assessment) Act 1989 (ICNA Act).

Read the definition of a 'naturally-occurring chemical'

If a chemical in your cosmetic does not meet the definition, it is considered to be an industrial chemical.

If you want to manufacture and/or import an industrial chemical, or a product containing industrial chemicals, for commercial purposes you will need to register your business with NICNAS.

Has any processing occurred?

Some chemicals in cosmetics can be obtained from nature without any processing at all, such as minerals and animal milk. Such ingredients comply with the definition of a 'naturally-occurring chemical'.

However most chemicals derived from nature require some type of processing before they can be used in a cosmetic product. To determine whether the chemicals in your cosmetic still meet the definition of a 'naturally-occurring chemical', you need to consider:

  • the process involved in deriving or extracting it, and
  • whether there has been a change in the chemical composition during the extractive process.

Non-invasive processes carried out at room temperature, such as cold pressing and dissolution in water, may meet the definition of a 'naturally-occurring chemical'.

If a chemical process is used, such as fractional precipitation, then the substance derived would no longer qualify as naturally-occurring. All synthetic equivalents of naturally-occurring substances are, by definition, relevant industrial chemicals.

Processes requiring the application of heat during extraction, unless to remove water, are subject to uncertainty regarding chemical change during the extraction process.

You should do your own research about your particular chemical to understand whether your extraction process creates any changes to its chemical composition.

Example—extracting essential oils

An essential oil is the volatile oil derived from some part of a plant, for example the leaf, stem, flower or peel, and usually carries the odour or flavour of the plant.

Essential oils are usually lipophilic compounds and therefore usually not miscible with water. Some essential oils are nearly pure single compounds, for example oil of wintergreen, however, most are mixtures of many chemicals.

Essential oils are often extracted from plant material by steam distillation. The hot steam opens the pockets in which the oils are kept in the plant material to release the aromatic molecules. An essential oil extracted by steam distillation does not meet the definition of a 'naturally-occurring chemical', particularly the requirement about the use of heat in part b (iv) of the definition.

In addition, there is uncertainty regarding the potential for chemical change during steam distillation. There are numerous scientific studies citing chemical change during steam distillation, including the thermal degradation of heat-sensitive compounds and the hydrolysis of other compounds.

Other common processes for extracting essential oils that do not meet the definition of a 'naturally-occurring chemical' are solvent extraction, supercritical fluid extraction (with CO2) and hydro distillation.

However some methods of extracting essential oils may meet the definition, particularly manual and mechanical processes, as long as there has been no change in the chemical composition. For example cold pressing is often used to extract citrus peel oils.

It is up to you to know enough about the process you are using to determine whether there has been a chemical change.

What is steam distillation?

Distillation is a separation process based on the difference in composition between a liquid mixture and the vapour formed from it.

The difference in composition is due to the different effective vapour pressures of the components in the liquid mixture.

The vapour is then condensed to a liquid (the distillate).

In steam distillation, steam is used to lower the distillation temperatures of high boiling organic compounds that are immiscible with water.

During the process, steam is charged to the matrix to volatilise the hydrophobic liquid and carry it across to a chilled condenser for subsequent liquefaction and separation from water.

The temperature and pressure of the steam need to be carefully controlled to prevent burning of the plant material or the essential oil.

Also, the distillation must be allowed to continue for such time to sufficiently extract the oil's components from the plant as some components are released more quickly than others.