Apple in conflict mineral 'name and shame' crackdown
Apple has begun publicising which of its suppliers may be sourcing minerals from conflict zones.
Conflict minerals, as they are known, are mined in areas of fighting or human rights abuses, such as the Democratic Republic of Congo.
The first published list detailed 104 suppliers that were unverified for compliance with ethical guidelines.
Electronics firms are being pressured by human rights groups to use their influence to force suppliers to change.
Most electronic devices contain either gold, tantalum, tin or tungsten. The gathering of these raw materials is often controlled by violent militias who may profit greatly from the activity.
"The ethical sourcing of minerals is an important part of our mission to ensure safe and fair working conditions," Apple said in its latest Supplier Responsibility Report, published annually.
"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."
The first published list showed that 59 smelters were compliant with its guidelines.
A further 23 have agreed to be audited by the Conflict-Free Smelter Program (CFSP), meaning their status should soon be known.
But the document stated that the status of 104 smelters was unknown, highlighting the scale of the challenge.
Bandi Mbubi is a director of Congo Calling, a UK-based campaign group calling for greater transparency in the sourcing of minerals, particularly for electronics.
He told the BBC that Apple's announcement was to be applauded.
"What we want is the whole industry to start transforming the way they do their business," he said.
"The way Apple has gone, even though it is not 100%, is something that is quite encouraging."
In an interview with the Financial Times, Apple's senior vice president of operations Jeff Williams explained why the company would not just use smelters it had identified as conflict-free.
"Quite honestly, if we did that, we could wave our conflict-free flag but it would do nothing to affect the workers on the ground," he told the newspaper.
"And so what we are focused on is getting a critical mass of suppliers verified such that we can truly influence the demand situation and change things."
Last month, Intel announced that it would no longer use conflict minerals in its microprocessors.
The declaration came as a response to a law passed in 2010 that gave companies a May 2014 deadline for reporting the source of its raw materials.
Mr Mbubi said he hoped the moves from Apple and Intel would spark a race for other technology companies to show they too were taking action.
"I think the competition has now started. I think very soon Microsoft will have to say something, or Nokia, or Samsung.
"The competition is good for places like the Congo."
Follow Dave Lee on Twitter @DaveLeeBBC