What it is
This ingredient is a soluble synthetic dye with a deep blue-violet hue. In tone-up and tinted sunscreens it is added at very low levels to neutralize yellow tones and lend skin a cooler, brighter optical finish. Because it is a dye rather than an opaque pigment, it tints the vehicle and blends with skin to adjust apparent color rather than providing coverage.
Safety & warnings
It is used at low concentrations as a colorant and is generally well tolerated. Because it imparts a strong blue-violet tint, formulators dose it carefully to avoid visible color transfer; it is not associated with the common fragrance-allergen list.
Origin & sourcing
Synthetic organic colorant.
Questions everyone asks
Why is a blue dye in a sunscreen?
The blue-violet tint counteracts yellow tones in the formula and on skin, producing the brightened, tone-up optical effect many products advertise.
Does it provide UV protection?
No. It is a colorant for cosmetic appearance and does not act as a UV filter.