The formula should still have สารกันเสีย by suggesting There are 2 types of recommendations. 1. In case you want to advertise as Preservative-Free (formula without สารกันเสีย ), use Mild Preserved Eco 1% due to its composition Mild Preserved Eco Not classified to be สารกันเสีย according to the FDA's requirements. Naturalness Recommended PaeoniaPreserve™ 1-2%Use Tea Tree Oil (Water Soluble) 5% in the formula, for disinfection must use สารกันเสีย you join me?