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 chemical waste cause?

Fire hazard

When Remy smoked the cigarette and threw is in the hazardous waste, the fertilizer aught fire. The reason was that the waste was inflammable which means that it can catch fire easily.

It was a fire hazard and immediate measures must be taken to tone down the fire.  If the fire is not controlled, it can spread and other chemicals can also catch fire causing the factory to burn down to ashes.