PHOENIX - Arizona firms are on the verge of getting new secrecy protections for the internal reviews they do of their health and safety practices.

On a 40-19 vote, the House gave final approval Wednesday to legislation creating a special "privilege" for such reports. In essence, that means they would be off limits to anyone suing the companies for damages caused by their practices or products. And that, in turn, could make it difficult if not impossible for challengers to win in court.

That privilege would not be absolute. Companies would have to actually fix the problem in a reasonable time to gain the protection.

With the Senate already having passed the measure, it now goes to Gov. Jan Brewer.

Brewer does not generally comment on pending legislation. But she signed a nearly identical proposal into law last year dealing with internal audits of environmental practices.

This new measure was described by Rep. Heather Carter, R-Cave Creek, as "cutting edge." She said its approval by the governor would make Arizona only the second state in the nation to have such a law, behind Texas.

Proponents contend the measure is good for business and ultimately will result in safer practices and products.

Carter said nothing in the legislation exempts companies from monitoring what they already are required to do under state and federal law. What it does, she said, is encourage them to take an extra step and actively search out problems, ranging from safe practices for their employees to safer products for their customers.

"It's a tremendous incentive to go beyond what is already required," she said. And if they fix those problems - a precursor to getting to shield the report - then everyone is better off, she said.

But Rep. Bruce Wheeler, D-Tucson, said he doubts the latter premise is true.

He cited the groundwater pollution problems around Tucson International Airport in the 1980s that left city wells polluted with trichloroethylene and area residents suffering from lupus and cancer.

Lawsuits eventually were filed against the companies involved in dumping the toxic industrial solvent. They resulted in cleanup efforts as well as funding of medical monitoring programs for those living there.

He said there were multiple parties involved in the use and disposal of TCE on the site since World War II, including the Air Force, the Tucson Airport Authority and Hughes Aircraft, now known as Raytheon Missile Systems.

Wheeler said if only one of those entities had chosen to do an audit of their practices and the others did not, "the contamination would have continued."

That, he said, undermines the contention of supporters that having a law like this in place will encourage firms to pay closer attention to their practices and clean up their own messes long before they become public health problems.

Wheeler said that without some positive reason for shielding these audits from view, there's no reason to approve the legislation.

"I don't believe in self policing," he said, saying he doubts the law will make anyone safer.

Rep. Catherine Miranda, D-Phoenix, said opponents are worrying too much. "This is not an immunity bill," she said.

"It makes Arizona's regulatory framework more competitive," Miranda said, to "help attract businesses to Arizona from other regulatory-burdensome states."