Hazard reductions burns are being hampered by longer fire seasons and extreme weather, Rural Fire Service Commissioner Shane Fitzsimmons says, warning the controversial technique is "not the panacea" some may be looking for to temper bushfires.

The Commissioner on Wednesday defended the RFS' record on hazard reduction burning, saying the agency was not comprised of "environmental bastards", indicating prescribed burns were done with the priorities of people, property and the environment in mind.

Commissioner Fitzsimmons said the agency had met its targets for hazard reduction in the lead-up to this bushfire season, but the "really awful" conditions across the drought-stricken state meant that fires had spread wildly regardless.

"Hazard reduction burning is really challenging and the single biggest impediment to completing hazard reduction burning is the weather," Commissioner Fitzsimmons told ABC Breakfast.