Apple has requested the Fair Labor Association (FLA) conduct special voluntary audits of its final assembly suppliers, including Foxconn’s Chinese factories in Shenzen and Chengdu.

The team of labour rights experts being led by FLA president Auret van Heerden started its inspection at the Foxconn City factory in Shenzen on Monday. Other suppliers, including Quanta and Pegatron, will be subject to similar inspections in the spring, with more than 90 percent of Apple’s product assembly covered by the end of the process.

Foxconn builds Apple’s iPhone and iPad devices but has been criticised by global media recently for its working conditions, with workers complaining of punishing shifts (leading some to reportedly threaten suicide). There were also two fatal explosions at plants manufacturing Apple devices in 2011.

Apple’s suppliers have agreed to cooperate fully with the FLA, allowing full access to their operations. The FLA’s first set of findings will be posted on the organisation’s website in early March.

The FLA will interview thousands of workers about living and working conditions with health and safety, compensation, working hours and communication with management all being covered. Manufacturing areas, dormitories and other facilities will all be inspected along with employment procedure documents.

Apple CEO Tim Cook said in a statement that the inspections are unprecedented in the electronics industry in scale and scope. “We believe that workers everywhere have the right to a safe and fair work environment, which is why we’ve asked the FLA to independently assess the performance of our largest suppliers,” he said.

In January Apple became the first technology company admitted to the FLA, which conducts independent monitoring to uphold its workplace standards in facilities used by its members. Apple has audited every final assembly factory in its supply chain since 2006, including more than 40 for Foxconn facilities alone.