What label color is used to indicate flammable materials?

The color red is used to indicate flammable materials because it is universally recognized as a warning signal for fire hazards. This color choice is intentional, as red has strong associations with danger and caution, making it an effective way to alert individuals about the potential risks of flammable substances. In various labeling systems, including the NFPA (National Fire Protection Association) and OSHA (Occupational Safety and Health Administration), red signifies fire and flammability, helping to ensure safety in workplaces and transportation scenarios involving hazardous materials.