A blue NFiPA label indicates

A blue NFiPA (National Fire Protection Association) label indicates specific health hazards associated with a material, particularly the potential for causing acute health effects. The label uses a numerical scale from 0 to 4, where 0 represents no hazard and 4 indicates a severe hazard. The blue section of the label is specifically focused on how toxic or harmful a substance can be to human health, guiding users in handling and emergency response situations.