Final Draft: Child-Specific Reference Dose (chRD) for School Site Risk Assessment: Paraquat

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The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency is making available for review and comment the Final Draft Report, “Development of Health Criteria for School Site Risk Assessment Pursuant to Health and Safety Code (HSC) Section 901(g): Proposed Child-Specific Reference Dose (chRD) for School Site Risk Assessment: Paraquat.”

HSC 901(g) requires the Office of Environmental Health Hazard Assessment (OEHHA), in consultation with the appropriate entities within the California Environmental Protection Agency, to identify those chemical contaminants commonly found at school sites and determined by OEHHA to be of greatest concern based on child-specific physiological sensitivities.  HSC 901(g) also requires OEHHA to annually evaluate and publish, as appropriate, numerical health guidance values (HGVs) or chRDs for those chemical contaminants.

The draft chRD for paraquat being considered at this time is 7 x 10-5mg/kg-day.  In developing the chRD, OEHHA selected two young‑animal studies and two adult‑animal studies.  Collectively these studies paint a cohesive picture that paraquat is a neurotoxicant and impacts brain functions.  The chRD is based on the lowest observed adverse effect level (LOAEL) of 0.07 mg/kg-day from one of the studies.

This public comment period follows the requirements set forth in Health and Safety Code Section 57003 for receiving public input. 

  • The initial draft was released on December 4, 2009, with a review and comment period ending on January 22, 2010.  This period was extended to February 22, 2010. 
  • A public workshop was held on January 13, 2010, in Sacramento.  Comments received at the workshop and during the comment period were considered during the revision of the draft document. 
  • The comments received and the response to those comments are included in the final draft report, which was made available to the public on the OEHHA website on August 12, 2010.
  • The Office of Environmental Health Hazard Assessment (OEHHA) received a request to extend the comment period on the final draft report.  In response to the request, on September 24, 2010, OEHHA decided to extend the end of the comment period from September 17, 2010 to November 16, 2010. 
  • The Office of Environmental Health Hazard Assessment (OEHHA) received a request to further extend the comment period on the final draft report. In response to the request, on November 4, 2010, OEHHA decided to extend the end of the comment period from November 16, 2010 to December 3, 2010. OEHHA requests that written comments on this draft report be submitted by 5:00 PM, December 3, 2010. Comments can be submitted using the address, fax number, or email address below.

If you would like to receive further information on this announcement or have questions, please contact Carmen Milanes by email at carmen.milanes@oehha.ca.gov, by phone at (916) 323-4153, or at the address below.

Carmen Milanes
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-12B
1001 I Street
Sacramento, California 95812-4010
FAX: (916) 322-9705