The Environmental Protection Administration (EPA) Thursday said it plans to develop a proposed rule requiring companies who make chemical substances and mixtures used in hydraulic fracturing (fracking) to report data on the chemicals.

The agency’s action, which was published in the Federal Register (FR) Thursday, comes nearly two years after Earthjustice and 114 other organizations petitioned the EPA (in August 2011) to require manufacturers and processors of oil and gas exploration and production chemical substances and mixtures to maintain certain records and submit reports on those records; submit to EPA existing health and safety studies related to E&P chemical substances and mixtures; and report information on significant adverse reactions to human health or the environment alleged to have been caused by E&P chemical substances and mixtures.

EPA denied the groups’ petition for an extended review of all chemicals used in the E&P process under the Toxic Substance Control Act (TSCA) because it was too broad. “The petitioners’ request is overly broad, and they have not demonstrated that the broad rule they requested is necessary,” the agency said. However, by virtue of partially granting the TSCA request, the EPA said it plans to initiate an advanced notice of proposed rulemaking (ANOPR) under TSCA to obtain data on chemical substances and mixtures used in fracking.

The proposal would bypass oil and gas producers and go directly to the chemical manufacturers. Questions to producers about the chemicals they are using are often met with the response that the producers don’t know the exact chemical mix they are using because it was a private formula provided by the manufacturers.

Although the EPA has partially granted the TSCA petition, it said it “is not committing to a specific rulemaking outcome…Our expectation is that the TSCA proposal would focus on providing aggregate pictures of the chemical substances and mixtures used in hydraulic fracturing. This would not duplicate, but instead [would] complement, the well-by-well disclosure programs of the states.”

The EPA informed the petitioners of its decision in November 2011, but it did not spell out the reason for the split decision until Thursday.

“EPA, other federal agencies and states have focused attention on hydraulic fracturing due to specific concerns raised about this practice, and most of the incidents and information sources referenced in the petition pertain to hydraulic fracturing. EPA believes information-collection under TSCA could significantly advance the federal government’s understanding of potential risks associated with this practice.”

The EPA said it already has broad regulations in place under TSCA requiring periodic reporting of extensive information with respect to chemical substances, including chemicals substances used in the E&P industry.

The petitioners requested that the agency develop a rule under TSCA requiring manufacturers and processors of E&P chemical substances and mixtures to develop test data to evaluate the toxicity and potential for health and environmental impacts. “EPA is denying this request as the petitioners have not set forth sufficient facts to support their assertions,” it said.

The EPA further shot down the petitioners’ claim that the industry data available to the EPA administrator “is insufficient to permit a reasoned evaluation of the health and environmental effects of all E&P chemical substances and mixtures, or that testing is necessary to develop such information.”

Moreover, the petitioners “have not shown that all E&P chemical substances and mixtures may present an unreasonable risk…Although petitioners provided examples of spills and releases and cited existing databases collecting health effects data, they did not show that any individual chemical substances or mixture, or the entire class of chemical substances and mixtures used in all phases of the E&P industry, may present an unreasonable risk.”

Meanwhile, the EPA continues to carry out its multi-year assessment of the potential impacts of fracking on drinking water resources. A report on the findings is expected to be finalized in 2016. The draft report is scheduled to be released for comment and peer review in late 2014. An interim update, the “Study of the Potential Impact of Hydraulic Fracturing on Drinking Water Resources,” was published in 2012, but it was found to be heavily flawed in an independent study by the Battelle Memorial Institute.