In a document filed with the U.S. Securities and Exchange Commission on Thursday, Apple details its conflict free minerals program that looks to push human rights on smelters and refiners by removing unaudited firms from its massive supply chain.

According to the specialized disclosure, ethical mineral sourcing is part of Apple's human rights initiative and, as such, the company is determined to use only "conflict free" minerals in its products. The report covers results of Apple's initiative for the 2013 calendar year.

Apple has been investigating the use and sources of tantalum, tin, tungsten and gold used in various iOS and Mac products since 2009. Unlike other companies that simply sourcing materials from verified smelters, Apple has taken a more proactive route and is currently pushing smelters and refiners to comply with the Conflict-Free Smelter Program.

As described by Apple, "conflict minerals" are materials sourced from the Democratic Republic of the Congo and neighboring regions, then sold to fund fighting and what amounts to human rights abuses.

With its huge market reach, Apple is in a prime position to make a change when it comes to ethical mineral sourcing and the company knows it. In February, Apple focused on conflict minerals in its annual Supplier Responsibility report, noting that substantial progress has been made in certain areas like tantalum production. Greenpeace, known to be critical of Apple's worldwide operations, lauded the company for its efforts a day later.

More work needs to be done, Apple says, but a plan is already in place to ween its supply chain off conflict minerals.

The three-pronged initiative includes:

Continuing to drive suppliers to ensure that their smelters and refiners obtain a "conflict free" designation from an independent third-party auditor of Subject Minerals

Continuing to pressure smelters and refiners directly to become verified as having "conflict free" sources of Subject Minerals, or have them removed from Apple's supply chain

Continuing to drive its suppliers to obtain current, accurate, and complete information about their smelters and refiners of Subject Minerals

To hold smelters accountable, Apple publishes their names, countries and CFSP status in a publicly-accessible list. Apple notes in the SEC report that over 400 suppliers were surveyed between 2010 and 2013. To date, Apple has identified 205 smelters and refiners that produce material used in its products and will continue to conduct in-person visits, third-party reviews and collaborative efforts with industry partners to ensure that the number of unaudited producers decreases to zero.