What colors are used on a sign to indicate hazardous chemicals?

The colors yellow and red are used on signs to indicate hazardous chemicals due to their high visibility and alerting nature. Yellow typically signals caution and indicates potential hazards, prompting individuals to be aware of their surroundings. Red is often associated with danger, signaling immediate attention or action, which is crucial when dealing with hazardous materials. Together, these colors effectively communicate the urgency and seriousness of the warning, ensuring that individuals can quickly identify and respond to potential threats posed by hazardous chemicals.

In contrast, the other color combinations do not effectively convey the same level of urgency or hazard. For instance, white and black may be used for informational or instructional signs, while blue is generally used for mandatory or safety-related messages rather than hazards. Green usually indicates safety or go-ahead signals, which would not apply in the context of hazardous materials. Thus, the pairing of yellow and red is specifically designed to provide a clear warning about the presence of dangerous substances.