Mr. John Wickham:

SI 12620 with respect to aggregates for concrete has particular threshold limits associated with the presence of deleterious materials and limitations on total sulphur. In 2016, the NSAI published SR 16, which makes provision for a full description of how manufacturers should demonstrate their knowledge of raw materials through petrographic assessment of the quarried material and a declaration of compliance for its intended use. This has been reinforced in parallel with a system of oversight by a notified body to ensure that factory production control is maintained at the quarry where that material is placed on the market and that there is appropriate competency of the professionals, equipment and process to deliver material that, ultimately, is fit for purpose.