What's in it? Dimethicone

Other names it goes by: Polydimethylsiloxane.

What's it used in? Over-the-counter drugs and food additive (E900) as an anti-foaming and anti-caking agent.

What does it do? It gives skin and hair products a soft, velvety feel or shine and acts as an emulsifier or emollient to coat the skin.

Any controversy? Some studies have found that prolonged exposure can cause skin irritation and clogged pores. Some synthetic emollients are tumour promoters, accumulating in the liver and lymph nodes, and are non-biodegradable.