Foxconn has also "committed to be more inclusive" of workers in health and safety monitoring and decisions. The survey said "a majority of workers were generally not involved in the safety and health committees and had relatively low levels of confidence in the management of those issues."

Part of the low confidence in management came from a lack of worker integration into the company's activities, FLA said. The committees lacked worker representation, and as a result failed to monitor working conditions effectively. Foxconn has agreed to "ensure elections of worker representatives without management interference," according to the study.

The key question following FLA's report is whether Apple and Foxconn will keep any of the promises they made, said Scott Nova, executive president of Worker Rights Consortium.

"They have been promising to end forced overtime since 2006, for example, and have not done it. I hope this will be different, but skepticism is in order until we see proof of real progress," Nova wrote in an email message.

Apple became an FLA affiliate in January 2012 and was not up to speed on the organization's code of conduct at the time of the investigation, FLA said. FLA provides a set of rules for internationally recognized labor standards that member companies can voluntarily implement, and the onus is now on Apple to enforce the rules.