Final answer:
The blue quadrant on the NFPA diamond-shaped symbol represents health hazards.
Step-by-step explanation:
The blue quadrant on the NFPA diamond-shaped symbol for hazardous material indication represents health hazards. The NFPA 704 Hazard Identification System uses different colored diamonds to indicate various hazards associated with a substance. The blue diamond specifically indicates the level of health hazard that a substance poses. It is rated on a scale from 0 to 4, with 0 being no hazard and 4 being extremely hazardous.