Waste Management has been ordered to pay $810,000 after a worker was killed from exposure to chemical poisons.
Jim Gideon died in August 2017 after being overcome by hydrogen sulphide gas from a treatment pit at Waste Management's facility in Seaview, Lower Hutt.
He had been directed to carry out a dangerous mixing of reactive chemicals to treat hazardous waste.
The waste was sitting unmarked at the site for six months before being dealt with.
During this time, the waste was never officially recorded, nor tested or labelled by the site chemist.
A destruction certificate was issued despite the waste having not actually been destroyed.
On the day of the fatal poisoning, the hydrogen sulphide alarm repeatedly rang at the site, but work continued regardless.
Gideon collapsed mid-afternoon, after exposure to at least 500 parts per million of hydrogen sulphide.
The maximum workplace exposure allowed is 10ppm over an eight hour period.
WorkSafe said there were a litany of failures by the waste company that led to Gideon's death.
Its investigation uncovered a breakdown of systems at the site, with health and safety failures at every level, including improper storage and hazard identification and a lack of personal protective equipment for workers.
In sentencing at Wellington District Court, Judge Davidson said a "wholesale systemic failure" had led to the creation of a "fatal gas chamber" at the facility.
He imposed a fine of $450,000 and ordered reparations of $360,000.