The OSHA Hazard Communication Standard (HCS) requires all chemicals in the workplace to be labeled in a manner that warns of any hazards the chemical may present. The actual format and method of labeling is not specified, so there are several different formats in use. The NFPA hazard diamond is one such method. Two other HCS compliance systems that are very similar to one another are described here.
The Hazardous Material Identification Guide (HMIG) is a labeling system developed and sold through Lab Safety Supply Inc. The Hazardous Material Information System (HMIS) is a labeling system developed by the National Paint and Coatings Association (NPCA) and sold through Labelmaster Inc. Both systems use a label with four color bars and a space at the top where the name of the chemical should be written (see figure this page). The blue, red, and yellow colored bars indicate, respectively, the health, flammability, and reactivity hazard associated with the material. These three bars use a numbering scale ranging from 0 to 4. A value of zero means that the material poses essentially no hazard; a rating of four indicates extreme danger. Although the details of how numbers are assigned may vary somewhat between systems, this is essentially the same overall scheme as is used in the NFPA system. (But see also the note on differences between NFPA and HMIG.) A discussion of health hazards and the terminology used to describe them is given in Appendix A of the OSHA Hazard Communication Standard (29 CFR 1910.1200 App A).
The fourth, white bar is marked "protective equipment" in the HMIG system, and "personal protection" in the HMIS system. Both systems (HMIG and HMIS) place a letter in this bar to indicate the kind(s) of personal protective equipment (PPE) that should be used in order to handle the material safely. The letters used are A - K and X. Meanings of the letters are the same in both systems, and both systems augment the letter code with icons or pictograms showing the kinds of PPE to be used.
A significant difference between the HMIG and HMIS systems is that the recently (1995) revised HMIS system now includes a second box on the blue (health hazard) bar. If this second box holds an asterisk (*), then the health hazard associated with the material is a chronic (long-term) effect. A Labelmaster press release summarizes other changes.
The University of Oregon introductory chemistry labs use a hybrid system to label materials. An NFPA diamond is used, but the white field is filled with a letter from the HMIG system. Posters placed at various points around the lab give a full description of the PPE symbols used.