Calcium Sodium Borosilicate

Synthetic bulking agent used in makeup, skin care, and other personal care products

May also provide some blue light protection and enhance SPF values of sunscreens

Supplied as smooth flakes, beads, or powder formed by the fusion of various compounds

Deemed safe by the Cosmetic Ingredient Review Expert Panel in up to 97% concentration

Calcium sodium borosilicate is a synthetic ingredient used as a bulking agent in makeup, skin care, and other personal care products. Bulking agents are solid ingredients that are used to dilute other solids or to increase the volume of a formulation.

In research literature, calcium sodium borosilicate is categorized as a borosilicate glass. Don’t let the word “glass” scare you—this isn’t glass that will cut you. Instead, it’s smooth flakes, beads, or powder formed by the fusion of various compounds. This ingredient has a long history of safe use in cosmetics.

Newer research has shown calcium sodium borosilicate may also be of interest for blue light/sun protection. One study showed a 5% concentration of calcium sodium borosilicate helped protect skin in the presence of blue light, while simultaneously enhancing the SPF value of the mineral sunscreen as used in the same formula.

In their 2013 report, the Cosmetic Ingredient Review Expert Panel surveyed 751 personal care products containing calcium sodium borosilicate ranging between 0.0001% to 97% concentration. Of these, 740 products were leave-on products (including 397 lipsticks with a max concentration up to 10%, body sprays at 0.5%-0.6%, and face powders at 4%-97%). Based on their analysis, calcium sodium borosilicate is safe in these concentrations and practices of use.