Shelf Life of Preservative-Free Formulas and Preservative Over-Addition
Asked by: armzaa002
On: July 07, 2015
Product Type:
Cosmetics
Question
I have two questions regarding formulation:
- What is the shelf life of a preservative-free formulation stored at room temperature?
- If I accidentally add more preservative than specified in the formula, but the total amount does not exceed the manufacturer's recommended maximum usage rate (e.g., not exceeding 1% total), is it dangerous, and how can I correct it?
Answer
Based on the information from the forum post:
Regarding the shelf life of a formulation without preservatives stored at room temperature:
- It is impossible to determine an exact duration.
- The shelf life depends heavily on various factors, especially contamination during preparation (e.g., from hands, sneezing, utensils, water).
- Once ingredients are dissolved in water, microbial growth can occur, regardless of the shelf life of the dry ingredients before mixing.
Regarding accidentally adding more preservative than the formula specifies (but not exceeding 1% total):
- If the amount added does not exceed the maximum usage rate recommended by the preservative manufacturer, it is generally not considered dangerous.
- To correct this, you can dilute the mixture by adding more water. However, this will also reduce the concentration of all other ingredients in the formula.