Abstract: A barrier, such as for example in relation to safeguarding of machinery and in particular to a barrier, a barrier panel for a barrier, and a mounting assembly for mounting a barrier panel in position to provide a barrier. The invention is particularly applicable as panel and barrier for use in relation to belt conveyor guarding. The barrier comprises at least one panel comprising a body having a marginal portion bounded by a peripheral edge and an inner portion, a plurality of openings extending through the inner portion, and a stiffening formation extending from the inner portion to the marginal portion, the stiffening formation being integrated with and being defined by a portion of the body.