An operative was injured when a 9-inch grinder he was using above his head kicked back and struck him in the face, requiring stitches. An investigation found that the safe system of work was vague, only describing the tool as a "small" grinder instead of specifying it was a 9-inch grinder. It also did not account for the dust generated by cutting concrete. The alert stresses the importance of ensuring safe systems of work are correct and adequate, and speaking up if they are not, in order to avoid injuries and keep all workers safe.