P4O use zinc oxide as their only active ingredient, and here is why:  + It is the only reef-safe UV filter available.  + Zinc oxide provides excellent sun protection and has several advantages over synthetic actives. Zinc particles sit on top of your skin and act as a reflective barrier (exactly like a mirror) to block both UVAs & UVBs from penetrating your skin and causing damage and ageing. + It is the only FDA* and TGA** approved broad spectrum sun protection ingredient, and unlike any other active ingredient, its concentration in a product has no limitation. It is also the EWG (Environmental Working Group) nº1 ingredient for skin protection. + Zinc oxide is also effective for healing the skin. It can be used to heal wounds, reduce the tenderness associated with sunburns and soften chapped skin. It is sometimes used as an acne treatment - it is believed to reduce the appearance of blemishes and reduce skin irritation and inflammation, reducing the number and severity of acne breakouts. * Food & Drug Administration (US).
** Therapeutic Goods Administration (AU).