Over several decades phosphine fumigation has gradually become essential to protect stored grain from pest damage. However, in view of the widespread development of phosphine resistance and shortage of alternative fumigants, the use of grain protectants in pest control needs to be re-considered. Because pests have developed resistance to most commonly used protectants, it is impossible to control these effectively with a specific protectant independently of other control methods. Better knowledge of factors that affect the performance of grain protectants could allow the development of more effective application technologies and the design of new control strategies. Furthermore, more research on the application of grain protectants may improve their effectiveness, which will help to overcome problems associated with phosphine resistance.