Enclosures containing calcium hypochlorite must be labeled with HAZARDOUS MATERIAL: CALCIUM HYPOCHLORITE using what colors?

• A. Red on White
• B. White on Red
• C. Black on Yellow
• D. Blue on White

Answer: (A)

Color-coding on hazardous material labels is meant to communicate danger quickly and clearly. For the label that identifies calcium hypochlorite, red text on a white background is used because it provides high contrast and immediate visibility, signaling a hazardous material that requires careful handling. Calcium hypochlorite is a strong oxidizer, so the red-on-white label helps responders recognize the material’s hazard at a glance and take appropriate precautions, such as avoiding contact with organics or acids and using proper PPE. Other color combinations would either be less legible or indicate different hazard classifications in other labeling schemes, so red on white is the chosen format for this particular label.