Preservative compositions are provided with improved stability. The preservative compositions comprise a combination of an amphoteric compound and 3-iodo-2-propynyl butyl carbamate (IPBC). In a particular embodiment, the compositions comprise a combination of a betaine compound and 3-iodo-2-propynyl butyl carbamate. The compositions in some embodiments have surprising stability. The preservative composition can be used in personal care products, household products, industrial products and materials. The compositions can be used in a variety of methods for the treatment of surfaces such as cellulosic surfaces, such as wood surfaces. The compositions can be used in one embodiment to provide stain resistance to wood.