Toomey said the new rule would greatly burden Pennsylvania manufacturers, such as Global Tungsten & Powers Corp. (GTP). 

"Today's decision will place onerous burdens and costs on our state's vital manufacturing industry at a time when we can least afford them,” Toomey said after the agency's commissioners agreed to adopt the rules Wednesday. "While I appreciate the humanitarian intent of the regulation, including recycled materials actually conflicts with the regulation's objective and will force Pennsylvania companies like GTP to use more expensive and less environmentally friendly materials.”

Under the rules, manufacturers that use tantalum, tin, gold and tungsten in their products would have to determine if their minerals came from the DRC. If so, the company would have to tell the SEC and publicly disclose it on its website. Similarly, if it knows the minerals it used came from scrap or recycled sources, it would also have to disclose that finding.

Toomey said many of Pennsylvania's manufacturers rely on recycled minerals and that it’s very difficult to source their provenance, burdening companies with new regulations.

“In this tough economy, we need to give our manufacturers the flexibility to grow their businesses and create jobs, not impose new burdens and costs on them," Toomey said.

Republicans have generally been critical of Dodd-Frank, saying businesses and banks don’t need more regulations because regulations harm the economy.