The Hazardous Material Information System label, or HMIS label, shows workers the potential dangers of hazardous materials and the precautions they must take to handle them. The four-part label contains various colors, numbers, letters and symbols that workers learn to decode and use to determine the proper course of action for the handling, transportation and disposal of hazardous materials.
The blue section indicates the potential health hazards involved in handling the material. The label includes two white squares, one of which contains a number. The number indicates the level of the health hazard, ranging from 0 (no hazard) to 4 (fatal). If the other white square contains an asterisk, this denotes a special warning that the material poses a potentially chronic health hazard if workers are repeatedly exposed to it or if they fail to follow the proper handling procedures.
The red bar indicates the material's potential as a fire hazard. The white square shows the level of fire hazard the material poses. A "0" signifies that the material is non-flammable. A "1" indicates the material has a flash point above 200ºF, which means it must be exposed to a heat source to ignite. A "2" means the material has a flash point between 100ºF and 200ºF. A "3" indicates that the material can ignite at temperatures between 73ºF and 100ºF. A "4" signifies that the material has a flash point below 73ºF, so it can ignite at room temperature.
The yellow bar indicates the material's potential to detonate. The white square shows the level of explosive hazard the material poses. A "0" signifies that the material poses no detonation hazard. A "1" indicates that the material is stable under normal conditions, but may become unstable at higher temperatures or when mixed with water. A "2" shows that an explosion is possible under normal temperatures or pressures. A "3" indicates that the material could explode if exposed to heat, water or shock. A "4" signifies a highly unstable material that is capable of detonating under normal conditions.
The white bar includes the protective equipment the worker should wear when handling the material. The white square contains a letter that signifies the safety gear item(s) the worker should use. Each subsequent letter indicates a higher level of protective equipment. For instance, an "A" symbolizes safety glasses, a "B" represents safety glasses and gloves, and a "C" signifies safety glasses, gloves and an apron. An "X" means that the worker should consult with a supervisor on the proper safety precautions.