A father-of-two died after being dragged into an industrial machine in Radlett, which caused "massive and catastrophic injuries" to his legs and lower body.
Jason Griffin, from Hatfield, died in the Harper Lodge Farm Industrial Estate, while he was attempting to clean the inside of a polystyrene compactor.
An inquest into his death, held in Hatfield today, revealed how Mr Griffin did not follow safety procedures before entering the machine.
The 31-year-old was working at a waste processing plant, which was being used by a company called Expert Logistics to dispose of furniture packaging, including polystyrene blocks, polythene bags and banding material.
Mr Griffin was employed by James Environmental Management and worked at the site as the depot supervisor.
He was trained how to use the SC-3000 screw compactor machine, and had a copy of its standard operating procedures.
This document listed a number of "danger zones" on the machine, including the hopper, where waste polystyrene would be placed before being compacted.
It described how four steps had to be followed before anyone could access this part of the machine, included disconnecting the power, padlocking the isolator switch, and placing a sign on the machine stating it was not to be use.
A colleague of Mr Griffin however claimed it was common practice for Jason to enter the machine via the hopper to clear blockages, caused by materials such like banding and polythene.
One colleague said he had told his boss, Phillip Robinson, about this in the weeks before Mr Griffin’s death, a claim he strongly denied.
Mr Robinson, director of James Environmental Management, said: "After Jason’s death I arranged to meet the other workers to reassure them that although the site was closed, they would be still be paid.
"That’s when Seb [another employee] said about Jason climbing in and out of the machine to clear blockages.
"I asked them why they didn’t tell me about it before and they just sat in silence. If I had known I would have dismissed them, putting your life in danger is gross misconduct."
On the morning of the day he died, Mr Griffin was described by colleagues as his normal self, but said he seemed a little tired.
His partner Cheryl spoke to him on the telephone at 4.25pm, but the conversation ended abruptly. The ambulance service was called ten minutes later.
Mr Griffin was found in the compactor hopper with "massive, catastrophic injuries" to his lower body, but no injuries to his upper body.
At 5pm paramedics announced Mr Griffin was dead at the scene. A pathologist later said he died from multiple traumatic injuries.
When the machine was investigated, a large quantity of entangled packaging and waste was found to be inside.
Coroner Edward Thomas said: "The machine clearly had bits in it that shouldn’t have gone in, taping, polythene and wood, which should have been separated.
"If the machine is still switched on, it will automatically operate after something touches the rollers, and they are very sensitive."
A jury recorded Mr Griffin’s death was accidental.
Mr Robinson added: "Jason’s references were excellent and in the interview he came across very enthusiastic and was far and away the best candidate.
"I got to like Jason an awful lot, he was a great guy and I had big plans for him in the company.
"He could have done a great job for us as a salesman outside the facility. His personality was better than what he was doing there."