This International Standard specifies acceptance sampling plans and procedures for bulk materials, on condition that the bulk sampling system has been demonstrated to be representative and unbiased in accordance with this standard. It provides requirements for the statistical basis of acceptance decisions, including the treatment of sampling, sample preparation, and measurement accuracy. This International Standard is applicable across all areas in which bulk materials are sampled, such as food and feed, chemicals, pharmaceuticals, etc. Acceptance sampling in accordance with this International Standard shall only be applied where the bulk sampling system has been validated and shown to be fit for purpose. Validation shall include demonstration that systematic sampling bias is negligible or has been explicitly corrected using statistically defensible methods, and that the relevant variance components associated with sampling, sample preparation, and measurement are known or have been estimated with adequate precision for the intended use. This International Standard covers cases in which the values of standard deviations at individual stages of sampling are known, as well as cases in which they are imprecise and have to be estimated. Where estimation is required, appropriate statistical methods shall be applied to quantify uncertainty and manage inspection risks at reasonable cost. Where correlation, stratification, non‑stationarity, or significant grouping or segregation effects cannot be excluded, acceptance sampling plans specified in this International Standard shall not be applied unless specialist statistical methods have been used to validate the sampling system. In such cases, validation shall be performed prior to the application of acceptance sampling and shall demonstrate that the assumptions underlying acceptance sampling are satisfied.