Which HMIS color indicates reactivity hazard?

The correct choice, which indicates reactivity hazard in the Hazardous Materials Identification System (HMIS), is yellow. In the HMIS color-coding system, yellow is used to represent the level of reactivity hazards associated with a material. This is crucial information for handling and responding to hazardous materials, as it helps individuals understand the potential for chemical reactions — such as explosions, the release of toxic gases, or other dangerous situations that can arise when incompatible substances are present.

Reactivity hazards are best visualized in terms of stability: a yellow designation warns that the substance can undergo rapid chemical reactions under certain conditions, such as heat, pressure, or contact with water or other chemicals. The number associated with the yellow color often quantifies the degree of reactivity, allowing individuals to assess and mitigate risks appropriately.

The other colors in the HMIS system have different meanings: blue indicates health hazards, red signifies flammability hazards, and white is reserved for specific information, such as personal protective equipment requirements. Understanding these distinctions is essential for proper safety protocols when working with hazardous materials.