Sizes : 1kg or 5kg
Bulk size : 22.78 kg *overweight fee of $30 applies to delivery.

Baking soda is a natural product that comes from the bottom of lakes. White powder with characteristic odor and salty taste.

INCI : Sodium bicarbonate

Properties: Whitener, cleaner, stain remover, fabric softener (it breaks minerals), deodorizer, softener

Uses: Household products, deodorants, toothpaste, bath bombs 

Usage: Used as is

Consult the recipe for making your own soda crystals (sodium carbonate).

Namely...

This baking soda is not certified alum-free, however the certificate of analysis confirms that it is below 2 parts per million, which is equivalent to 0.0002%.
According to the manufacturer; sIf aluminum exists as an alum compound in the natural mineral we use to make baking soda, the traces would be insignificant.