A security module for use with a ventilation grating comprising a body, a base with a planar surface for attachment to the grating, and an outer wall extending from the base. The body has inner passageways extending from the base to the outer wall, the first portion of which extends from the base in a direction perpendicular to the base, and the second portion of which extends from the outer wall to intersect perpendicularly with the first portion within the body. The security module, when attached to a ventilation grating, prevents threading a rope-like material, through the grating, and using the make-shift rope to commit suicide by hanging, and is therefore particularly suitable for use in penal institutions, hospitals and mental health facilities.