[c1sc0]

Good question! Because we produce in the EU we need to list all ingredients. The sodium hydroxide is a Ph stabilizer commonly used in low doses in cosmetics. It was actually the FIRST thing I asked our lab when they gave me the final INCI.

[tape_measure]

Yes, I suppose having a concentration of hydroxide is good to keep the carbonate from reacting and bursting the packaging.

[c1sc0]

The way I understood it is that Ph needs to be within a certain band of values in cosmetics and the last ingredient in the INCI guarantees this.