Apple has said an independent group, the Fair Labour Association, has started inspecting working conditions in the Chinese factories where its iPads and iPhones are assembled.
Amid growing criticism over labour and environmental practices - especially in China - Apple last month disclosed a list of suppliers for its popular gadgets for the first time.
The FLA team began the inspections at Foxconn City in Shenzhen, China, Apple said. The complex employs and houses hundreds of thousands of workers.
Foxconn, a unit of Taiwan's Hon Hai Precision Industry, employs an about a million people in China at a series of huge factory campuses. Foxconn assembles iPads and iPhones for Apple, Xbox 360 gaming consoles for Microsoft and other gadgets for companies including Hewlett-Packard and Dell.
In 2010, there was a rash of suicides at Foxconn's Shenzhen plant. Plant managers installed nets to prevent more people from committing suicide by jumping from the roof. A May explosion at the company's Chengdu, China, plant killed three people and injured 15.
A New York Times story published January 26 reported on accidents and long hours in Foxconn factories, based on workers' accounts. Foxconn disputed allegations of back-to-back shifts and crowded living conditions.
California-based Apple has been conducting its own audits of working conditions at factories where its gadgets are assembled since 2006. A month ago, it took the additional step of joining Washington-based FLA, a group of companies and universities focused on improving labour practices.
Apple, the most valuable company in the world, is the first technology company to become a member. It committed, at the time, to have the FLA inspect its suppliers, who have pledged full cooperation.
The FLA plans to interview thousands of employees at several Apple suppliers about working and living conditions and the audits will cover facilities where more than 90% of Apple products are assembled. The FLA's findings and recommendations will begin to be posted on www.fairlabor.org in early March.
Consumer activism site Change.org gathered 200,000 signatures for a petition to ask Apple to protect workers around the time of new product releases, when the workload spikes. Activists hand-delivered printouts of the signatures to Apple stores last week, but the group has stopped short of arranging protest gatherings or calling for a boycott.