Most of our products are stable at room temperature for a few weeks, but we recommend storage at 4°C or -20°C to extend their shelf life. Our solid powders are stable at room temperature for weeks. For some of our aqueous dye solutions, the compounds are also stable at room temperature, but we recommend cold storage to prevent mold growth over time. We have taken every effort to save shipping costs, thus less temperature-sensitive products with recommended storage at 4°C or -20°C may be shipped at ambient temperature without affecting product performance. When you receive the product, store them under the recommended storage conditions.