Bioprocess technology combines living organisms with nutrients under optimal conditions to produce desired products. It allows small amounts of useful substances produced in labs to be scaled up economically through advances in fermentation, separation, and purification techniques. Primary metabolites are intermediate compounds produced during bacterial growth that are necessary for survival. Secondary metabolites are end products produced during stationary phase that are not essential for growth but can have defensive properties and be toxic. Bioprocess technology is attractive to industry because it can utilize waste as raw materials to create new cheaper products and has low energy requirements applicable to less developed countries, though it could also enable biological weapons programs.