Alternative form of nonhazardous.

plural of potentially hazardous object

(astronomy) A near-Earth asteroid or comet with an orbit such that it has the potential to make close approaches to the Earth and is of a size large enough to cause significant regional damage in the event of impact.

(Australia) A deliberately lit fire in bush or grassland, under favourable conditions, used to reduce the fuel available for a wildfire.

plural of hazard reduction burn