Nearly 80 percent of American companies surveyed by two human rights groups failed to meet a U.S. rule requiring they monitor whether their products contain minerals from war-torn Africa.

The joint report by Amnesty International and Global Witness is the first by outside groups to analyze so-called “conflict mineral” disclosures by U.S. public companies complying with the Securities and Exchange Commission rule.

“The conflict minerals law is an opportunity to clean up global mineral supply chains. But our analysis shows that most companies seem to prefer business-as-usual,” Carly Oboth of Global Witness said in a statement.

The survey of 100 companies found that 79 percent of them failed to meet all the minimum requirements, and 41 percent to show they had policies to identify risks in their supply chain.

The report did not cite which companies fell short of all the requirements, but it gave credit to those that met the standards such as 3M Co, Tiffany & Co, General Electric Co, Tesla Motors Inc and Hewlett Packard Co, among others.

The 2010 Dodd-Frank Wall Street reform required manufacturers to determine whether any tin, tungsten, tantalum or gold in their products came from the Democratic Republic of the Congo. The region is known for using the proceeds from mining to fund rebel groups who kill and rape civilians.

The SEC rule took effect in 2014 after a U.S. appeals court upheld most of its provisions following a legal challenge by the U.S. Chamber of Commerce and other trade groups.

To comply, companies must conduct a country of origin inquiry, file a public report for investors and carry out due diligence on their supply chains.

The human rights groups looked at how well the companies complied with 12 core requirements.

None of the companies disclosed any examples of supply chain risks, although some of them reported possibly having some gold from North Korea.