Formula 4. Natural sunscreen SPF 20*

Mineral sunscreens were formulated using 30–40% w/w micron-sized ZnO dispersions (15–20% ZnO) to develop formulations with an SPF of 20–30+ (see Formulas 4, 5 and 6) and at this loading, the formulas were not found to cause skin whitening (data not shown).