A standard bulk bag is rated at a 5:1 Safety Factor Ratio as per ISO 21898 norms, which means that the bag is specified to hold 5 times the amount of the bag’s safe working load.  A 5:1 Safety Ratio is for single-use or single trip bags.  Bags that are designed for multi-use or multi-trip bags are made with an increased SF ratio.   The SF for a multi-trip bag is 6:1.