On each product, there is an open jar symbol with a number on it. That number indicates how long you can use the product once it is opened. Rather than using chemical preservatives, we use natural preservatives and anti-bacterial herbs. 100% PURE® has several other unique proprietary technologies that distinguish the company from competitors. We use unique technology to stabilize active ingredients from oxidizing and also have a proprietary 100% natural preservative system, using Japanese Honeysuckle, Thyme, Oregano, Goldenseal, Rosemary, Lavender and a high concentration of vitamins and antioxidants, to preserve all products.