(AP) -- Federal officials have moved quickly to clamp down on the use of potent rodent-killing pesticides after one was linked to the deaths of two Utah girls earlier this year.
The U.S. Environmental Protection Agency said aluminum and magnesium fumigants can no longer be used near homes. The agency added other regulations about where they can be used outside and what kinds of warnings must be posted when the fumigants are applied.
EPA officials said Thursday they had planned to review the pesticides in the coming years as part of normal procedures.
"Obviously this tragedy in Utah kicked us into high gear," said Marty Monell, EPA's deputy director in the office of pesticide programs.
Four-year-old Rebecca Toone and her 15-month-old sister, Rachel, died in February after an exterminator treated their yard in Layton with poison-laced pellets used to kill rodents. Investigators said they believe toxic phosphine gas from the pellets seeped into the home and sickened the girls.
The Utah Medical Examiner's Office said both girls had elevated levels of phosphorous and lung damage "consistent with inhaling a harmful substance," according to a statement issued this week by the Layton Police Department.
Aluminum and magnesium phosphide fumigants are primarily used to battle bugs in grain silos and other agricultural operations. Less frequently, they're used to kill underground rodents.
"The problem has come with use in what we call the residential setting, around homes," Monell said, adding that a South Dakota girl also died several years ago after one of the fumigants was applied near her home.
The EPA is required to review those kinds of chemicals every 15 years. The phosphine fumigants were scheduled for review in 2012 or 2013 but that was moved up quickly after the Utah deaths.
The new rules, which went into effect Wednesday, ban the use of phosphine fumigants near residences, nursing homes, school buildings, hospitals or day care centers. They can only be used to kill rodents in agricultural areas, orchards, golf courses, cemeteries and other outdoor areas where people don't live. Those treatments now must have signs indicating that a dangerous chemical is being used.
Previously, EPA rules said the fumigants couldn't be used with 15 feet of a building that might be occupied by people. That buffer zone is now 100 feet under the new rules.
New labels will be sent out to registered users detailing how the fumigants can be applied.
The changes should significantly reduce the misuse of a highly toxic pesticide, Monell said.
Meanwhile in Utah, prosecutors plan to decide in the next week or so whether charges will be filed in the Toone case, said Troy Rawlings, Davis County attorney. The possibilities range from no charges to a misdemeanor to second-degree felony for reckless homicide, he said.
In a statement, the Toone family declined to discuss specifics of the latest developments but said they "applaud any efforts by government officials to continually seek to improve the safety of our community."
Explore further: Katrina residue dangers questioned