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Newly Available Data to be
      Incorporated into Pyrethroid Proposed Interim Decisions 
      
 
Based on a thorough review of recent
      data, EPA concluded that there are reliable data to support reducing the
      current threefold (3X) Food Quality Protection Act (FQPA) safety factor for pyrethroids to 1X, and
      that margin will be safe for infants and children. This reduced safety
      factor will be incorporated into the upcoming pyrethroid proposed interim
      decisions for registration review. 
EPA is required to apply a 10X margin
      of safety, or safety factor, to human health risk assessments to account
      for potential prenatal and postnatal toxicity of infants, children and
      pregnant women when exposed to pesticides. The law allows a different
      margin of safety only if the Agency has reliable data supporting a
      conclusion that the revised safety factor would protect infants and
      children.  
The Agency considers the FQPA safety
      factor to have two components: one assigned to pharmacokinetic (PK)
      differences and another for pharmacodynamic (PD) differences. The PK
      component refers to the process of chemicals being absorbed, distributed,
      metabolized and excreted from and in the body. The PD component refers to
      how a chemical affects the body’s tissue. 
In 2010, EPA reviewed the data relevant
      to assessing the health risks of pyrethroid exposure to infants and
      children and found that they supported the removal of the safety factor
      for PD. However, the data were insufficient to change the PK portion of
      the uncertainty factor, thus leaving a 3X safety factor 
More recently, EPA has performed a new
      evaluation of available guideline and literature studies, as well as data
      generated by the Council for the Advancement of Pyrethroid Human Risk
      Assessment. The Agency concluded that the FQPA safety factor for
      pyrethroids should be reduced to 1X for all populations (1X for PD and 1X
      for PK) because the data indicate that there is no increased sensitivity,
      or in other words, there are no PK differences between adults and
      children. 
Pyrethrins and pyrethroids are
      insecticides widely used in and around households, including on pets.
      They are also used in treated clothing, mosquito control, and
      agriculture. 
We invite stakeholders to review the
      methodology and EPA’s conclusion to lower the FQPA Safety factor. EPA
      will be accepting comments on the white paper once the Federal Register
      notice announcing availability of the pyrethroid Proposed Interim
      Registration Review Decisions is published later this year. Once the
      Proposed Interim Decisions are published, comments should be submitted to
      www.regulations.gov under docket # EPA-HQ-OPP-2008-0331. 
      
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