Disclosed is a zinc oxide powder comprising zinc oxide aggregates which when used in a dispersion at a concentration of 10 wt% of zinc oxide, produces a transparent composition having a total visible transmittance through a path length of 20 microns at 550nm of at least one of at least 70%, at least 75%, at least 80%, at least 85% or at least 93%, the powder having a number average zinc oxide aggregate size of at least 0.8 microns or at least 1 micron, wherein the aggregates are mesoporous and have a total mesopore volume of at least 0.25 cm3/g or at least 0.35 cm3/g or at least 0.5 cm3/g.
