The OSHA requirements related to machinery and machine guarding are provided in 1910 Subpart O, with the general requirements for all machines detailed in 1910.212. This standard covers types of guarding and how specific machines and work areas should be guarded.
The different machine guarding sign headers correspond to the hazard severity that the marked machines represent. While the “DANGER” header signifies a hazardous situation that, if not avoided, will result in death or severe injury; the “WARNING” header is for similar cases where death or severe injury is possible, though not certain.
When there is a possibility of minor or moderate injury if a hazard is not avoided, use safety signs with the “CAUTION” header. Signs with “NOTICE” headers communicate important information that is not particularly hazard-related, and those with “SAFETY FIRST” headers convey instructions or procedures related to safe work practices.