(1) Protective devices should, as far as possible, be integral parts of the machine;
(2) Fully enclosed guards should be used whenever possible, except where unavoidable (such as with bench grinders);
(3) Protective devices should be positioned as close as possible to the hazard zone to enclose it;
(4) Protective devices should not interfere with production operations;
(5) Protective devices should be designed to allow maintenance work to be performed with minimal risk;
(6) Materials used for protective devices should generally be metal, specialized plastic sheeting, or glass, unless wood is required due to special circumstances.
