DES MOINES - State environmental regulators have given preliminary approval to new health rules for livestock operations.
However, the Iowa Environmental Protection Commission said the guidelines for hydrogen sulfide gas from large-scale factory farms may be changed later.
The Department of Natural Resources is proposing the standard for hydrogen sulfide in the air near area rural homes, churches, schools and other public buildings. It would be used to determine if the levels pose health risks to people.
During the EPC's meeting on Monday in Urbandale, representatives of Iowa State University told the commission that the original limit they approved with colleagues at the University of Iowa - 15 parts per billion - may be too strict.
No one from the University of Iowa, which employs the human-health researchers who studied the issued, addressed the commission during Monday's meeting.
Final approval will come after a series of public hearings. The guideline would need to be approved by a committee of lawmakers, too.
Commissioners Kathryn Murphy of Le Mars and Heidi Vittetoe of Washington voted against the preliminary approval.
Last year, the EPC passed rules to set standards for ammonia and hydrogen sulfide. The Legislature said those limits were too strict and were set up to apply to businesses not covered by the original legislation.