Mineral Makeup doesn't contain liquid, binders, or bio-ingredients that break down. Minerals are also naturally anti-bacterial, they create an inhospitable environment for bacteria to grow. The only thing in silk naturals that can break down is the silk protein and nothing really chemically wrong happens to it. That's one of the great bonus features of mineral powders- they don't have a shelf life. The lippies and cream concealers and skincare DO have a shelf life and so do liners and mascara. I toss them when the oils go off. With my lippies and concealers I do periodically cut an eighth of an inch off the top to prevent bacterial growth. Mascaras I toss about every 6 months.