By Valerie Volcovici

WASHINGTON (Reuters) - The Obama administration announced its first steps on Friday toward what could be tighter regulation of hydraulic fracturing, or fracking, that has revived U.S. oil and gas production, seeking public input on whether companies should be forced to disclose the contents of so-called fracking fluids.

The U.S. Environmental Protection Agency said it would gather public comment for 90 days on whether it should require chemical manufacturers to disclose what is in the fluids that are injected into shale seams to release trapped oil or gas, a technology that has transformed the oil and gas industry.

The so-called "advanced notice of proposed rulemaking" came as a response to a petition by the environmental group Earthjustice under a section of the Toxic Substances Control Act (TSCA). The act enables anyone to petition the EPA to initiate an amendment or repeal of rules requiring chemical testing, imposing regulatory controls and requiring information.

The EPA said its notice may not result in any formal measures at all, and it would consider non-regulatory approaches.

“Today’s announcement represents an important step in increasing the public’s access to information on chemicals used in hydraulic fracturing activities,” said James Jones, EPA’s assistant administrator for the Office of Chemical Safety and Pollution Prevention.

He told reporters Friday that the agency wants to use the process to learn what is happening at the state level and what voluntary mechanisms are available for reporting.

Although drillers fear greater disclosure may jeopardize commercially secret formula for the fluids they use to coax the maximum oil or gas out of a given well, the industry has become more transparent in recent years, responding to concerns about potential public health implications of fracking.

Hydraulic fracturing is regulated on a state-by-state basis and currently does not face significant federal oversight. Some of the biggest oil and gas producing states already require some level of disclosure about the mix of chemicals and fluids they use to frack thousands of wells across the country.

Earthjustice had asked the EPA to require chemical manufacturers and processors to publish detailed information about the content of fluids used in fracking. It also requested that those companies submit all health and safety studies available on those fluid mixtures.

The EPA had denied other parts of Earthjustice's 2011 petition, including a request for companies to conduct toxicity tests on fracking liquids. The agency said in its initial response to the 2011 petition that it would take an approach that would "minimize reporting burdens and costs" and try to avoid duplication.

Deborah Goldberg, an attorney with Earthjustice, said Friday that stringent federal rules are needed because not all states are equipped to regulate.

"Some of the states do something. Some don't. A lot of the disclosure they require is enforced rarely and poorly," she said.


(Reporting by Valerie Volcovici; Editing by Jonathan Leff, Ros Krasny, Susan Heavey and Nick Zieminski)