The Australian Workers’ Union (AWU) wants tighter regulation following a giant factory fire in Melbourne.

A worker seriously was burnt at the Bradbury Industrial Services Campbellfield factory late last week, after a stockpile of highly hazardous materials caught fire.

The blaze required over 175 firefighters to control it, spewing thick black smoke over Melbourne and taking several days to be extinguished.

Victorian coroner Darren Bracken has launched an investigation into the incident following a request from the fire brigade.

Victoria's Environment Protection Authority (EPA) had suspended Bradbury Industrial Services’ licence to accept waste in mid-March.

The licence was revoked after an inspection found the company had 400,000 litres of hazardous materials on site, despite only being permitted to store 150,000 litres.

Australian Workers' Union (AWU) secretary Ben Davis said a worker suffered an eye injury in the blaze, and another was taken to hospital with serious burns.

“He's not well, he will survive, but he's not well, he's in the burns unit at the Alfred Hospital,” Mr Davis told the ABC

“He was working out there at the company … when the fire started, he was immediately transported to the Northern Hospital and then from there to the Alfred hospital, and as we all know you don't get to the Alfred unless you're quite unwell. He is quite badly burnt.”

A fundraising page has been set up to support the worker, Vigneshwaran Varatharajan.

Mr Davis said that before the blaze, staff believed hazardous waste had not been removed properly and that conditions were unsafe.

“There's got to be a better system of laws and regulation around the industry,” he said.

“I'm not saying the EPA are the bad guys in this, because I don't think they are.

“I think they are underfunded and under-resourced, that's the real issue, but we do need to get to the bottom of it all.

“They [Bradbury Industrial Services] were told not to accept any more material, but they weren't actually being told to remove that which was there and that's the problem.”

EPA executive director Damian Wells says the watchdog had visited the site numerous times over the last few months, and withdrew the company’s licence just one day after it was discovered that far too much material was being stored.

He also foreshadowed potential action.

“This operator has shown no regard for the community in which they operate so we will be looking to investigate this matter absolutely to fully drag them through the courts to hold them to account,” he said.