All the tests on Cathy Behr were negative. As the medical mystery deepened, her body began failing.

Finally, doctors at Mercy Regional Medical Center diagnosed a chemical exposure that happened in their own emergency room, where Behr works 12-hour shifts as a nurse. She had treated a sick gas-field worker and breathed the fumes on his clothes from a chemical called ZetaFlow for five or 10 minutes.

Behr has largely recovered, but her ordeal has the community asking fresh questions about the chemicals used to extract the area's natural gas - the gas that heats millions of American homes and serves as an economic engine for the Four Corners.

ZetaFlow and similar chemicals are exempt from many federal and state environmental laws.

Few people know exactly what companies are pumping into the ground. It's a trade secret, and the companies like Weatherford, which supplies ZetaFlow, do not share their recipes with government regulators.

A state agency wants that to change. The Colorado Oil and Gas Conservation Commission's staff has proposed forcing companies to entrust the state with a list of all the chemicals they use to drill and operate a well. Energy companies oppose the plan, and the commission is scheduled to vote on the idea next month.

La Plata County commissioners support the proposed rule, but they want to strengthen it with greater protections for emergency workers.

"This is a public health issue that must be addressed," the commissioners said in a written statement.

EPA says not to worry

It's difficult or nearly impossible to get information about what companies pump into the ground. The federal government, however, says the risk chemicals like ZetaFlow pose to water wells is minimal.

ZetaFlow is used for hydraulic fracturing, or fracing, which entails pumping large amounts of liquid and sand into a well to break the rocks and let the gas flow out.

The Environmental Protection Agency abandoned a study in 2004 on frac-fluid use in coal-bed methane wells, saying its investigation showed no risk.

"EPA has concluded that the injection of hydraulic fracturing fluids into CBM wells poses little or no threat to (underground sources of drinking water) and does not justify additional study at this time," the agency wrote in June 2004.

The next year, Congress exempted frac fluids from the Safe Drinking Water Act as part of the 2005 energy bill.

The EPA did sign an agreement in 2003 with the three major fracing companies - Halliburton, Schlumberger and BJ Services - in which the companies volunteered to stop using diesel fuel to frac coal-bed methane wells. The four-page document is silent about other fracing chemicals.

An EPA spokeswoman in Denver did not return a call Friday.

U.S. Rep. Henry Waxman, chairman of the House Oversight and Government Reform Committee, conducted a hearing last October about the lack of regulations over gas and oil chemicals. Waxman's committee still has an ongoing investigation into the issue, said spokeswoman Karen Lightfoot.

"We've not got to the point where we have anything to release," she said.

OSHA, state also have a say

In addition to the EPA, the Occupational Safety and Health Administration also regulates gas-well sites. OSHA did 114 gas and oil inspections in Colorado in 2007, said John Healy with the agency's Englewood office.

OSHA's rules require employees to be trained and chemicals to be labeled, but the agency doesn't have to approve which chemicals are used. Companies have to report accidents to OSHA only if someone dies or at least three people go to the hospital.

The state of Colorado does not regulate the content of frac fluids, although next month it could adopt rules to require chemical disclosure.

U.S. Rep. John Salazar, D-Manassa, thinks people should know what chemicals are being used around their land and water, said his spokesman, Eric Wortman. Salazar supports repealing the Safe Drinking Water Act exemption, Wortman said, although there's no realistic chance of that happening this year.

"This year is going to be tough," Wortman said. "Hopefully with the next Congress, there will be more of a chance to work on some of these issues."

U.S. Sen. Ken Salazar, D-Colo., believes the state should handle the topic, said his spokesman, Michael Amodeo, although Salazar continues to monitor the issue.

"In the end, it's a state issue, especially with those rules being considered," Amodeo said.

Data sheets 'laughable'

Those rules will be up for a vote next month. The Colorado Oil and Gas Conservation Commission's proposed changes would require companies to keep a list of all the chemicals they use in the field.

Industry witnesses who testified last week said the COGCC staff's idea creates heavy burdens for recordkeeping. And, Halliburton managers said they would pull their secret formula out of Colorado if forced to disclose it.

Wells would lose as much as 30 percent of their production without Halliburton's secret formula, said Dale Davis, a company executive, at a COGCC hearing.

Hydrofracing happens in rock formations far below the aquifers tapped for drinking water, so there's little risk of water pollution, said Ron Hyden, another Halliburton manager.

The Colorado Petroleum Association, an industry group, made a counterproposal: The companies will keep Materials Safety Data Sheets for all the chemicals they use on well sites, unless the chemical is a trade secret. In that case, they would just list the chemical's name and manufacturer.

The ill worker at Mercy arrived at the hospital with a data sheet, but the sheets often aren't useful, said Theo Colborn with The Endocrine Disruption Exchange, based in Paonia.

Her group put together a list of the chemicals used in Colorado's gas and oil industry and found that 93 percent of them have adverse health effects. She based most of her information on data sheets, which are often incomplete, she said.

"In essence, it's up to the companies to decide what to put on the label," Colborn said. "That's all we have. That's what we have been basing our information on."

Mercy doctors found the same thing when treating Behr. The sheet listed the chemical as a "proprietary phosphate ester."

In another example, Halliburton's data sheet for CBM Frac Fluid says it "contains no hazardous substances," and under the Notes to Physician, it says, "Not applicable."

"It's laughable," Colborn said. "It's so right in your face - so bad. It just shows what little control the government has over this."

Risk not as high, study says

However, a public-health consultant from Denver said Colborn is overstating the dangers.

Dollis Wright with Quality Environmental Professional Associates criticized the TEDX study because it listed the chemicals that could be used by the industry, but it didn't have enough information to say how - or if - they could actually poison people.

"It needs to be very clear that just because a chemical is in your environment doesn't mean it's going to make you sick. It's got to get into your body," Wright said.

People can be poisoned by ingesting, injecting, breathing or absorbing chemicals, she said.

Wright did a health study of four Colorado gas basins for the Colorado Oil and Gas Association, which represents many energy companies. She ruled out the possibility that residents who live near wells would inject gas and oil chemicals or absorb them through their skin, leaving water and air as possible routes of poisoning.

The study included groundwater samples within half a mile of several well sites.

"The data that I looked at, there was no groundwater data that showed there could be a problem," Wright said.

And the air samples she studied showed no contamination traveling downwind in harmful amounts.

Wright stressed that her study for COGA was based only on the information available, even though she thinks that information is reliable.

If there's one thing the two sides can agree about, it's the need for information.

"I truly believe there needs to be more research done," Wright said.

County Commissioner Wally White, a frequent critic of the gas industry, also wants to know more.

"In 10, 15, 20 years, will we have a Love Canal here?" said White, referring to the New York community where toxic waste sickened residents in the 1970s. "Twenty, 25 years down the road, will these environmental things come back to bite us? Nobody knows."

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