What it is
Phenyl Trimethicone is a derivative of silica.
What it does
Phenyl Trimethicone is a silicone that has a drier finish than Dimethicone. It creates a protective barrier on the skin that slows down water loss.
In hair care products Phenyl Trimethicone is used to enhance the look and feel of hair by providing body and sheen and to improve the texture of damaged hair. It is also used to protect hair from the heat of a blow-dryer and other styling tools.
In addition it is an anti-foaming agent: it reduces the tendency of products to generate foam when shaken.
Phenyl Trimethicone is generally considered safe.