Though the U.S. Environmental Protection Agency’s newly released data reviews showed mixed results for Tier 1 screening of the first 52 pesticide chemicals in its Endocrine Disruptor Screening Program, the crop protection and chemical industries generally are pleased with the process thus far.
CropLife America, whose member companies produce, sell and distribute virtually all the crop protection and biotechnology products used by American farmers, specifically support the EPA’s “two-tiered approach to protect public health from chemicals with unintended, harmful effects,” said Jay Vroom, president and chief executive.
The program’s “thoroughly developed approach,” Vroom said, allows the EPA to separate “effective chemicals that benefit society from ones that should not be near people.” He added that CropLife America members have committed “significant resources” to help develop the federal program and will “continue to work with EPA to help get effective products to growers so that everyone has access to safe, nutritious and affordable food.”
The EPA’s Tier 1 screening data will help the agency determine whether endocrine-disrupting chemicals, or EDCs, have the potential to interact with a person’s estrogen, androgen or thyroid hormonal systems. The chemicals identified from Tier 1 to have potential interaction with the endocrine system subsequently will move on to Tier 2 of the screening process. The results of the Tier 2 tests then will act as a guide for the EPA’s final determination of whether a substance may have an adverse impact on the endocrine system under normal conditions of use, and any subsequent product regulation change.
Specifically, the EPA’s screening program uses a weight-of-evidence approach as the process for characterizing the extent to which the available data support a hypothesis that an agent causes a particular effect, according to the Endocrine Policy Forum.
This approach allows the EPA “to confidently determine whether a substance needs further testing to find out if it affects public health negatively,” said Janet E. Collins, CropLife America’s senior vice president of science and regulatory affairs.
Collins said the organization will be reviewing the Tier 1 results more closely.
Likewise, David Fischer, senior director of the American Chemistry Council’s Chemical Products and Technology Division, called the EPA’s data review a “significant milestone” because the agency’s approach also acknowledges that current exposure levels and exposure frequencies are essential elements of risk assessment.
“This methodology provides welcome clarity to the process and will provide EPA with the information needed to make decisions on whether further testing may be needed for the List 1 substances,” Fischer said.
The Endocrine Policy Forum also points out that inclusion on List 1 doesn’t mean the chemical is automatically an endocrine disruptor. A chemical on this list was chosen “based on the presence of the chemical in at least three of the four designated exposure pathways” -- food, water, residential and occupational -- not because of the chemical’s potential to cause endocrine effects.
“From the start,” said Ellen Mihaich, the forum’s scientific coordinator, “EPA has made it clear that the selection of the chemicals for Tier 1 screening was by no means a determination that the substances were harmful.”