California regulators released draft rules Tuesday that would govern hydraulic fracturing, or "fracking," involved in oil recovery.

The proposed rules were posted online by state oil regulators. California currently oversees oil well construction, but it had not previously required disclosure of fracking practices.

Under the draft regulations, operators would have to name the chemicals used in fracking and test wells to ensure the drilling process could be withstood.

Fracking is a method of extracting hard-to-reach gas and oil by pummeling rocks deep underground with high-pressure water, sand and chemicals.

It has been quietly going on in several counties including Los Angeles, Kern, Monterey and Sacramento to extract hard-to-reach oil. Other states use the technique to recover natural gas.

Environmentalists worry that fracking can contaminate groundwater and pollute the air. However, the industry has said the practice has been safely used for decades.

The release of the draft was just the first step in creating the regulations, which will undergo public comment starting in February.

"These regulations ... go well beyond disclosure requirements to require rigorous testing and evaluation before, during and after hydraulic fracturing operations to ensure that wells and geologic formations remain competent and that drinking water is not contaminated," California's Department of Conservation said in comments posted on its website.

"Some of the testing and evaluation requirements of the proposed regulations have not yet been implemented by any other state," it said.

While the chemical disclosure requirement was hailed by some fracking critics as an important step forward, California's draft rules also include a "trade secrets" exemption.

The exemption would allow a company to bypass public reporting of the specific chemicals in "fracking fluid" if that information would reveal information that competitors could use to gain an advantage.

In lieu of specifics, companies would be required instead to post the "chemical family or similar descriptor" for the agents it is using.

Also, doctors and nurses treating anyone harmed by a chemical spill or groundwater contamination would also be required to sign non-disclosure agreements before a trade-secret protected company would identify the chemicals it uses.

"These draft regulations would keep California's fracking shrouded in secrecy and do little to contain the many threats posed by fracking," Kassie Siegel of the Center for Biological Diversity said in a statement.

An oil industry spokesman did not immediately return a call seeking comment on the new regulations.