From the Supplier Responsibility report:

At Apple, we believe in making complex things simple. We strive to design products that are intuitive and enrich people’s lives. Behind that simplicity lies one of the biggest supply chains on the planet. Products like iPhone, iPad, and Mac all depend on the contributions of more than a million people across the globe, employed by both Apple and our hundreds of manufacturing partners.

Each of those workers has the right to safe and ethical working conditions. So we audit deep into our supply chain and hold our suppliers accountable to some of the industry’s strictest standards. In fact, we care as much about how our products are made as we do about how they’re designed.

On limiting the length of the work-week:

We’ve strengthened our programs to help suppliers protect student interns and other at-risk workers. We’re continuing our efforts to end excessive work hours. In 2013, our suppliers achieved an average of 95 percent compliance with our maximum 60-hour workweek.

On adding oversight training to the supply chain:

To address the shortage of qualified environment, health, and safety (EHS) personnel in China, we launched the Apple Supplier EHS Academy — a formal, 18-month program we believe to be one of the most comprehensive EHS training and education programs in any supply chain. In 2013, over 240 personnel representing factories with over 270,000 workers enrolled in this program. The EHS Academy will improve worker health and safety throughout the industry.

On ethical sourcing of materials:

The ethical sourcing of minerals is an important part of our mission to ensure safe and fair working conditions. In January 2014 we confirmed that all active, identified tantalum smelters in our supply chain were verified as conflict-free by third party auditors, and we’re pushing our suppliers of tin, tungsten, and gold just as hard to use verified sources. To heighten smelter accountability and help stakeholders follow our progress, we are releasing, for the first time, a list of the smelters and refiners in our supply chain along with their verification status.

There’s a lot more here, but this is excellent work. Apple should be proud of their efforts to fix a problem that is pervasive in the electronics industry. This is making a difference in ways that will not be obvious, but are incredibly important.