Jacek Adamowicz, 29, worked at Hitchen Foods, which is owned by Bakkavor Group. On 4 February 2015 he was sweeping the storage yard when a stack of plastic bales collapsed on top of him.
The Health and Safety Executive (HSE) found that Bakkavor Foods had failed to plan how the bales should be safely stacked and stored, and had not provided formal training for employees who were responsible for carrying out the task.
It also said there was no safe system of work for staff exposed while the bales were being moved, and that monitoring in the area was lacking.
Bakkavor Foods, whose customers include Tesco, Sainsbury's, Waitrose and M&S, pleaded guilty to breaching s 2(1) of the Health and Safety at Work Act. It was fined at Manchester Crown Court and ordered to pay costs of £32,595.
After the hearing HSE inspector Ian Betley said: "Bakkavor Foods fell far short of the required standard expected. Not only should proper planning have been carried out in relation to the storage and stacking of waste bales, but also a system of work subsequently put in place to mitigate both risks. The company failed on both of these counts with devastating consequences."