Federal regulators are now taking a hard look at imposing stricter controls on a pesticide believed to have caused two Layton girls to die -- revisiting safety restrictions they drafted and then abandoned nearly a decade ago.

In 1998, a coalition led by the tobacco industry beat back the U.S. Environmental Protection Agency's proposed regulations that, in effect, would have banned the residential use of aluminum phosphide.

The pesticide creates phosphine gas, used as a chemical weapon in World War I, and is now suspected in the poisoning deaths of 4-year-old Rebecca Toone and her 15-month-old sister, Rachel, earlier this month.

On Thursday, EPA's Marty Monell said her agency is reconsidering the use of metal phosphides around homes in light of what happened to the Toone sisters. The deaths of two other girls -- a 5-year-old in South Dakota and a 4-year-old in Texas -- have previously been blamed on the use of aluminum phosphide for residential pests.

"We've kicked into high gear," Monell said, "because this is a tragedy that, to our understanding, could and should have been avoided."

Investigators believe the pesticide was misused in its application near the Layton home and in the other suspect deaths.

The EPA's scrutiny is supported by Clark Burgess, director of Utah's pesticide office. His team continues to probe whether Bugman Lawn and Pest Inc. followed the law when it used Fumitoxin at the Toone home on Feb. 5.

"I obviously think this [pesticide] needs to be reevaluated to make sure this doesn't happen again," said Burgess, "I'm sure we all agree."

One who disagrees is Joel Seckar, a toxicologist who helped lead an agriculture industry coalition campaign that ended in 2001 with EPA giving up proposed tougher standards for phosphine pesticides.

"If people do follow the label," he said in a telephone interview Thursday, "I don't think there's going to be any problem with phosphine."

Now a consultant in North Carolina, Seckar was chief toxicologist for the R.J. Reynolds tobacco company during its successful effort to derail curbs that would, in his industry's words, "make it virtually impossible for our industry to continue to fumigate stored tobacco." Plugging the leaks in tobacco warehouses would cost the industry $50 million," tobacco companies said.

What were the coalition's main concerns?

EPA said in its December 1998 proposal that it had "identified risks that must be reduced" before the pesticides could be re-approved. They included:

» a 100-foot no-phosphine zone around homes and 500-foot no-phosphine zone around occupied structures;

» a 750-foot warning area in neighborhoods where phosphine was to be used; and

» reducing maximum allowable exposures to one-tenth of previous limits.

Said an agency fact sheet from 1999: "EPA believes that protective measures in addition to current use restrictions are needed to protect bystanders in residential and occupational settings, as well as pesticide applicators, from exposure to the highly toxic phosphine gas that is created when these pesticides are used."

The EPA was reassessing all pesticides at the time. Metal phosphides had been in use already for more than a decade and had become a powerful and effective tool that not only eliminated pests from commodities, like grain, beans, animal feed and tobacco but also left no harmful residue.

Though tobacco companies like R.J Reynolds wanted to be able to use phophine to control cigarette beetles, these other agricultural uses helped the coalition grow to around 150 members, including the American Farm Bureau Federation and even the U.S. Agriculture Department.

In the end, the EPA's proposed buffer zones were scrapped completely, and the pesticide was cleared for use outside 15 feet of homes, as it previously had been and remains now. And the EPA's plan to require warnings for neighbors up to 750 feet away were abandoned, too.

The agency also dropped the tougher exposure limits, agreeing with coalition-sponsored scientists that humans were no more vulnerable to phosphine than the rats and other rodents the chemical was tested on.

Though he called the Toone girls' deaths "obviously very terrible," he said current regulations are appropriate for phosphine-based pesticides. "I think we did everything right," he said.

Gina Solomon, a medical doctor who works for the environmental group, the Natural Resources Defense Council, has pored over thousands of pages of internal documents that have been released since the tobacco-industry settlements that began around the time of EPA's phosphine review.

"EPA started out with a really good risk evaluation," she said. But then the coalition mobilized, using former-EPA scientists and a "science-for-hire firm" to build a body of evidence that would tip the risk-benefit analysis in industry's favor.

Solomon said the coalition's tactics succeeded in large part because of the tobacco industry's experience in influencing the regulatory process.

"The story [of the Toone sisters] is horribly sad, but really it's not that surprising."

Not only are pesticides toxic chemicals but "it's predictable that accidents will happen" when they become widely available.

"Appropriate, scientifically based regulations would have prevented this," Solomon said. "EPA regulations did not force the level of precaution that there should have been."

The EPA's Monell defended her agency's actions by noting the federal law requires the agency to work with stakeholders and balance the risks of a pesticide's use against its benefits.

"At a certain point in time," she said, it was clear that the benefit of it outweighed the risk, and the risk was mitigated to at least be equated with the benefit. Obviously, that dynamic has changed."

EPA has a range of options it could take, if deemed necessary, from clarifying label instructions for aluminum phosphide to banning its use near homes.

Solomon, meanwhile, felt a familiar sense of helplessness when she heard about the Toone girls. Then felt a twinge of hope.

"You want to learn the lessons you can from the tragedies that occur," she said, "because otherwise its a useless tragedy. Whereas, when you can learn a lesson from it, then it actually becomes useful and can save lives."