remy is smoking too closely to a building that manufactures fertilizer. when he puts out his cigarette near the hazardous waste, it sparks a fire because the fertilizer is flammable. what kind of hazard did the hazardous waste cause?

The hazardous waste caused a physical hazard, specifically a fire hazard.

In this scenario, the fertilizer is described as flammable, and the spark from Remy’s cigarette ignites it, starting a fire. That means the danger comes from the physical property of the material (its flammability), not from it being poisonous or causing a chemical burn, which would be chemical or toxic hazards instead.