LOS ANGELES (AP) — Southern California's huge Farmer John meatpacking plant on the edge of Los Angeles has been assessed more than $58,000 for safety violations state officials say exposed more than 300 workers to COVID-19 infections, including three who were hospitalized.

The state Department of Industrial Relations, known as Cal/Osha, says the violations were uncovered during an investigation that took place at the Vernon, California, plant between May and November, adding that some serious COVID-19 infections were traced as early as February.

The plant's corporate owner, Smithfield Foods of Virginia, said Monday it has worked hard to ensure employees at all its plants remain safe from COVID-19 and will aggressively contest the $58,100 in proposed penalties.

Meatpacking and poultry processing plants across the country, where employees work in close proximity slaughtering animals for food, have been a hotbed for infections since the coronavirus struck early this year.

In July, the Centers For Disease Control and Prevention reported more than 16,000 cases in 23 states.

Cal/Osha reported in September that it issued more than $200,000 in proposed penalties against frozen food manufacturer Overhill Farms Inc. and the agency it contracts with for failing to protect hundreds of employees at two plants in Vernon.

Local 770 of the United Food and Commercial Workers union said its complaints prompted the recent investigation of Farmer John, where thousands of pigs are slaughtered to make hot dogs, sausages, bacon and other products.

“In the absence of leadership from Smithfield, we have taken it on ourselves to call for safer working conditions and an investigation from Cal/OSHA,” said Farmer John employee Jose Guzman.

The union said Farmer John employment contractor CitySolutions Inc. was also issued $47,000 in separate penalties. CitiSolutions, whose contract workers are mentioned in the Farmer John citations, declined to comment and Cal/Osha didn't immediately elaborate.

One of several citations Cal/Osha issued against Farmer John said the company failed to report three employees who were hospitalized with the coronavirus between Feb. 14 and April 28. The agency also said its inspection revealed the company “failed to consider at least 303 COVID-19 illnesses of its own employees and contract employees of CitiStaff Solutions.”

Smithfield Foods Chief Administrative Officer Keira Lombardo said the company fully complied with Cal/Osha's investigation, providing more than 4,000 documents. She added that many infections could have been brought in from outside the plant, noting that in the early stages of the pandemic there was no clear guidance on contact tracing or how to protect people.

“To date, we have invested more than $650 million in extensive workplace protective measures, including masks, face shields, reconfigured workstations, plexiglass barriers and robust social distancing mandates,” she said.