Abstract: A safety cap includes a cowling containing an internally threaded closure member. The top of the closure member is provided with a central conical boss engaged by a cylindrical split ring on a top panel of the cowling to normally bias the two components into a first position. Downward pressure upon the cowling to a second position engages teeth on the two components to permit turning of the threaded closure member. The biasing action between the two components when moved between the first and second positions is enhanced by a tapering of the thickness of the cowling top panel to its minimum thickness juxtaposed the split ring. The lower portion of the closure member may include a series of saw tooth ridges to facilitate its retention during fabrication.