Labor rights groups have claimed that the owners of a factory in China that supplies parts for Apple products are mistreating its workers. China Labor Watch and Green America said Thursday that a factory owned by Catcher Technology Co. in Suqian, China, was found to have what it termed "serious health and safety, environmental, and human rights violations."

The facility makes metal covers for iPads along with various other parts for the fifth-generation iPhones. China Labor Watch said that during its investigation in August, between 500 and 600 workers from Catcher Suqian were moved to another one of the factory's locations, in the city of Taizhou, to work on the soon-to-be-released iPhone 6.

The problems found in Suqian last month were discovered by an undercover activist who got a job at the factory. The issues included locked safety exits, a lack of safety training, hiring discrimination, excessive hours for workers, and forced overtime. China Labor Watch estimated that each employee of the factory works six hours of unpaid overtime per month, meaning workers are owed wages of approximately $290,000.

Toxic Conditions

China Labor Watch also said it found shavings of aluminum-magnesium alloy on the floor and dust particles in the air, the presence of which poses health and fire risks. It also claimed that the factory dumps industrial fluids and waste into groundwater and nearby rivers, and added that workers in Suqian don’t have the necessary equipment to handle toxic materials.

In a statement, Green America said the investigation raises concerns about the working conditions in Apple's supplier factories. The organization said that it made the information public to "encourage Apple to take immediate next steps in addressing toxins and unsafe working conditions in their factories as Apple continues to ramp up production of the iPhone 6."

Worker conditions in factories that serve the electronics industry has come under increased fire recently. Samsung is among the other companies that has faced criticism. China Labor Watch has discovered supplier issues in the past when it has investigated Apple.

Apple Defends Itself

For its part, Apple has said it will hold its partners to higher standards. It has done investigations of its own, published supplier reports, and instituted stricter work policies on its suppliers.

In response to the most recent scrutiny, Apple stated that it is committed "to ensuring safe and fair working conditions for everyone in our supply chain" and that it makes it a priority to investigate every specific concern brought to its attention.

"We audit the facility's aluminum wet-polishing systems every month and consistently find that they exceed international safety standards," Apple stated. "As a result of our quarterly fire-safety inspections, the most recent of which happened last week, Catcher has made same-day repairs of broken and expired fire extinguishers, unblocked corridors and fire exits, and added missing emergency exit signs."