Lactic acid solution at pH below 3. Safety and preservative need
I have made this product and 5 people including me have used it for a month daily or once each two days without any problem or side effect.
It is a 5% lactic acid solution at pH below 3. It is just 5% lactic acid in water with 0.1% tetrasodium EDTA.
My questions are
1. Is it safe to use 5-10% lactic acid at pH around 2.5?
2. Does it need preservative if i use only lactic acid and EDTA in water and pH below 3?
3. If it is not safe to use then, is it safe to use this product and then apply a 2% sodium salicylate solution on top of that to increase its pH when on skin or apply a moisturizer lotion on top of that to increase its pH when on skin?