Financial regulators in the US are cracking down on investment funds that are marketed as climate-friendly but frequently hold shares in high-carbon fossil fuel companies, and have only marginally lower emissions per dollar of revenue than the economy average.

The proposed rules by the Securities and Exchange Commission will require purveyors of exchange-traded funds and other retail investment products labeled as “ESG” to disclose more information about what kinds of companies are included in those funds and the rationale for their inclusion. Today that information is frequently withheld or buried in technical documents that leave average retail investors susceptible to greenwashing. And ESG funds are allowed to hold up to 20% of their shares in non-ESG stocks, so that even funds labeled “fossil fuel-free” can, and do, hold fossil fuel companies. The new rules won’t necessarily close that loophole, but will at least make it easier to spot.

“Right now anyone can call a fund ‘green,’ and ‘green’ doesn’t need to reflect anything real about the fund,” said Greg Hershman, head of US policy for Principles for Responsible Investment, a United Nations-backed research and advocacy group. “This is about setting some rules of the road where today there are none.”

Read the rest of this story on qz.com. Become a member to get unlimited access to Quartz’s journalism.