Seconds later, he was hit by a massive fireball that would melt his skin and leave him with scars he still bears almost five years on.

Cosmetic giant Revlon and the ACT government this week agreed to pay Mr Sumners and two other injured men compensation worth a cumulative $6.7 million over the blast at a medical waste disposal facility in 2009.

The mothers of two of the men also received six-figure payouts each as carers.

The defendants will also pay costs, taking the total payout to about $8 million.

The matter officially settled by consent in the ACT Supreme Court on Thursday.

The trio received burns to their faces, hands and bodies when aerosol cans exploded in a machine at the SteriHealth facility on December 15, 2009.

It was the first day on a project at the facility for Mr Sumners, then 24, of Cronulla, and the other men – all electrical contractors.

They had spent the morning moving materials, such as electrical cable, through a tunnel connecting the SteriHealth building to the neighbouring Capital Linen Services premises.

Mr Sumners said they were leaving for lunch when he noticed a strong smell of perfume.

He commented to a colleague, who had just replied, when they were hit by a giant fireball.

Blinded and enveloped in intense heat, they ran from the building to a maintenance shed, where they crowded under showers until paramedics arrived.

Mr Sumners said he remembered asking if he would survive, before being bundled into an ambulance and taken to hospital, where he was sedated and flown to Royal North Shore Hospital.

He woke up weeks later.

The court on Tuesday heard the blast had been caused when pressurised aerosol cans – cosmetic waste from Revlon's Hume premises – were shredded by an industrial machine, releasing a highly flammable vapour.

The chemicals exploded, injured the three men.

The intensity of the blast and fire also damaged a window, melted a tarpaulin and burnt nearby bales of hessian.

Mr Sumners, now 28, received the worst injuries.

His head, legs, arms, and lungs were all damaged and he still bears angry scars.

The damage also means he can longer regulate his own body temperature properly, cannot stand in the sun, and has to take pain killers each day to combat nerve pain.

He is self-conscious of his appearance, has suffered depression, and has been forced to give up the electrical trade he loved.

"The emotional impact has been one of the hardest barriers to overcome," Mr Sumners said.

"[I've gone from being a fit and active 24-year-old] to having this astronomical accident, then going through recovery, and now reaching a point where I've started to realise these are the injuries I have to put up with for the rest of my life; it's not going to get any better.

"It's been a big strain on my family [so the case ending] is a massive relief, I'm just so glad I can now put this whole situation behind us."

Mr Sumners said he now hoped to retrain in the building industry and to marry his long-term girlfriend, who had been a rock of support throughout his ordeal.

"Life is scary now, but I want to be productive. I'm a worker and have always been on the move," he said.

"I just want to move on and do the best I can do with the ability I have."

The other injured men declined to be interviewed, but both said they were "very happy" with the result of the case.

Lawyers for Revlon complained in court on Thursday of the adverse publicity the cosmetic giant had received as a result of the case.

But Mr Sumners said the negative exposure had been minor compared with the hardship he and the other two victims had suffered in fighting a legal battle against a billion-dollar corporation.

He revealed his disgust at the company meant he would never again buy Revlon products.

Mr Sumners' solicitor, Irena Pechanats, of Shine Lawyers, said the size of the payout had been due to the fact the trio were contractors.

That meant the case fell under the Civil Wrongs Act, rather than Workers Compensation legislation, which limited damages.

Ms Pechanats said the case highlighted the inconsistency of legislation governing workplace accidents.