DENVER -- When a Colorado emergency room nurse fell gravely ill after treating a gas-field worker, doctors struggled to figure out what was wrong with her.

Her liver, heart and lungs were failing, likely a result of inhaling ZetaFlow -- a substance used in natural gas drilling -- from the patient's boots. But doctors could find little treatment information in the medical texts or on the Internet because the fluid's formulation is a closely guarded trade secret.

"Nobody knew exactly where to go," said nurse Cathy Behr, 56, who since has recovered.

New regulations adopted in December to govern Colorado's booming oil and gas industry aim to make future incidents easier to handle by, among other things, requiring companies to disclose to doctors and emergency workers the ingredients they use.

Regarded as the most comprehensive in the country, the rules have been hailed by some as providing much-needed protections for the wildlife and environment, but assailed by others as punitive -- and potentially crippling -- for an industry critical to Colorado's economy.

"We think these are the right regulations for Colorado," said Dave Neslin, acting director of the state's Oil and Gas Conservation Commission. "The oil and gas industry ... has a large footprint within the state. We think these rules strike an appropriate and sustainable balance."The requirements come as Colorado is struggling to keep pace with a significant energy boom. A decade ago, state officials issued 1,000 drilling permits per year; in 2008, they are on pace to issue more than 7,600, Neslin said.

The regulations:

-- Create a 300-foot-wide protection zone around streams that provide drinking water.

-- Require operators to disclose information about their chemicals to emergency responders and physicians, although the information may not be released publicly.

-- Require emission controls on operations within a quarter-mile of schools and homes in northwestern Colorado.

-- Allow state health and wildlife officials to review applications for operations that could affect public health or wildlife habitat.

The Colorado Oil and Gas Association, an industry trade group, regards that last rule as particularly onerous.

"As a result ... this process becomes the most burdensome in the nation," said John Swartout, vice president of government and legislative affairs for the association.

Swartout said it already takes longer to apply for a permit in Colorado than in other gas- and oil-producing states -- an average of 65 days, compared with two to seven days in other states.

Neslin acknowledged the process takes too long because commission staffing levels haven't kept pace with the growing number of permits.

"We face particular challenges here in Colorado," including drilling in areas of important wildlife habitat, he said. "In Colorado, it would be difficult to do a thorough review in two or three days."

The new regulatory climate could dissuade companies from operating in Colorado, Swartout warned.

"You're going to see a significant drop in investment in the Rocky Mountains. That equates to a loss of jobs in our state -- good-paying jobs with health care and benefits," he said.

Several Republican state lawmakers have echoed that concern, saying they intend to push for modifications to the rules.

"We cannot afford to push the energy industry out of Colorado, given the current state of the economy," said Colorado House Minority Leader Mike May to The Denver Post. "And many fear that the proposed rules will do just that."

Environmentalists counter that tourism is a far more important industry in Colorado and that it makes sense to protect the natural assets that draw visitors to the state.

Hunting, fishing and outdoor recreation "are contingent on an environment that's thriving," said Pam Kiely, legislative director for Environment Colorado.

The argument that the rules will contribute to a worsening economy is flawed, said Elise Jones, executive director of the Colorado Environmental Coalition.

"What affects the oil and gas industry is really the price of natural gas, which is set on the national market," Jones said. "It's influenced by things that have nothing to do with whether they have to line waste pits."