I would like to know as well. I am working on a hair cream pH 5. I am using benzyl alcohol and dehydroacetic 1%. Is that enough for an effective preservative system? I have seen in the market other hair creams with only Cosgard as Preservative. Ingredients are aqua, mango butter, sweet almond oil, lactic acid, aloe vera and BTMS.
Shall I add a bit of phenoxyethanol and EDTA to boost the system or just leave it like that? What %?