Natural selection Going green? Four things to know.

1 Few products are truly all-natural Even if every ingredient started as a plant, chemicals may be used to process the extracts or derivatives.

2 Natural potions may need special handling The purest formulas are those you could have made in your kitchen. There are natural preservatives (citric acid is one), but these might not keep ingredients fresh and safe to use for as long as the synthetic versions do, explains skincare specialist Catherine Wells. She tested 25 natural preservatives, exposing them to bacteria and heat, and settled on a synthetic for her otherwise-natural line.

If you do use products free of chemical preservatives such as parabens, choose opaque, airtight pump bottles and tubes, rather than jars, which involve your fingers – and germs.

3 Natural ingredients aren’t always gentler Poison ivy is natural, after all! If you’re allergic to something, such as nuts or certain flowers, applying a lotion that contains that component could also cause a reaction.

4 Natural and organic are not interchangeable Organic ingredients are grown without synthetic pesticides, but this isn’t true of all natural ingredients. And products labelled organic may contain organic ingredients, but not be limited to them.