A "toxic" explosive industrial fire is under control in Bundaberg after firefighters worked until 2:00am to manage the blaze.

Lindsay Transport chief executive Kim Lindsay confirmed the fire started at the transport company's Bundaberg depot on Zielke Avenue yesterday afternoon.

He said all workers made it out safely but expected several trailers would have been destroyed.

"It's hard to get in at the moment because it's under investigation, but one of the main sheds and cold rooms are definitely gone," Mr Lindsay said.

"We got all the workers out first and most of the trucks but we lost one B-double, six lead trailers and some refrigerated lead trailers.

Queensland Police initially declared an emergency zone when the fire broke out and that was fully revoked this morning.

Queensland Fire and Emergency Services area commander Trevor Duncan said the fire involved a variety of items including semi-trailers, plastic crates, gas bottles and pallets.

"We had something like eight trailers on fire, so you've got the contents of those, plastics and tires and all that sort of thing," he said. 

"That would have produced all that black smoke and it was quite a lot, you know, very toxic."

Mr Duncan said the operation was "all hands on deck". 

"We had something like eight fire and rescue appliances and we also had four rural fire appliances attend," he said. 

"We also got aid from some city council tanker to supply us with this additional water for around the back of the premises. 

"At one time, we had 44 firefighters on the ground."

While the cause of the fire is under investigation, Mr Duncan says it may be related to the transfer of gas behind the depot.

"There was some decanting of gas happening at the rear of the premises at the time," he said.

"They were more than likely filling a gas cylinder from one gas on to another and it might have been on the forklift or something like that.

"I'm just going to get that confirmed, whether something went wrong in that process."

Business as usual

Mr Lindsay said apart from the inconvenience of having to relocate operations, it was "business as usual" for the transport company. 

"We're working direct off our farms and we're still doing 300-odd pallets of produce out of the day," he said.

"We're very resilient, we've had floods, we've had fires, so we're very used to these things and we have great people that can recover very well from them."

Mr Lindsay also thanked the community for their concern and assistance.

"We've always had a great relationships with our farmers and they're supporting us very much, so look it's just a thankyou to the community," he said.

"People have been ringing often to help us out with anything we need — sheds, depots and things like that.

"So the support has been very overwhelming to be truthful."