The waste management company director has been jailed for eight months over the death of a worker who was crushed while clearing a machine blockage.
Polish national Zbigniew Galka, 39, died after suffering haemorrhaging, shock and severe traumatic injury while working at Gaskells Waste Services in Bootle, Liverpool, in 2010.
Jonathan Gaskell, 47, of Tarporley, Cheshire, admitted breaching health and safety laws at Liverpool Crown Court.
His company was also fined £700,000.
A joint investigation by the Health and Safety Executive (HSE) and Merseyside Police found Mr Galka died on 23 December 2010 while trying to fix a machine which compresses waste material into small bales.
A HSE spokesman said the machine had a system which allowed a worker to enter it while it was still in operation ,but its safety system had been disabled two months earlier.
He said Mr Galka had crawled into the baling chamber of the machine to clear a blockage, but the machine had automatically restarted.
The 39-year-old suffered haemorrhaging, shock and severe traumatic injury to both legs and died on his way to hospital.
The joint investigation found Gaskell's (North West) Ltd - which was also ordered to pay about £100,000 in costs - had continued to operate the machine in a dangerous manner for up to five years after Mr Galka's death.
Speaking after the hearing, HSE inspector Phil Redman thanked Mr Galka's family for their "patience throughout this complex investigation" and said his death had been "completely avoidable".
"It is inconceivable that Gaskells continued to operate the same dangerous machine in the way it did for as long as five years," he added.
A Gaskells spokeswoman said Mr Galka was "an absolute tragedy", which continued to have a "lasting effect" on the company.
She said employee safety was "absolutely paramount" and the company had "learned lessons" taken steps to "safeguard our staff".
She added that the company "hold a small memorial service at the plant" on the anniversary of the 39-year-old's death.