1. Future Science Issues of BFRs Linda S. Birnbaum Director, Experimental Toxicology Division NHEERL Research Triangle Park, NC Region 2 Science Day/Non-Regulated Pollutants Workshop NYC – October 25, 2005 Linda S. Birnbaum Director, Experimental Toxicology Division NHEERL Research Triangle Park, NC Region 2 Science Day/Non-Regulated Pollutants Workshop NYC – October 25, 2005

2. Why BFRs? Flame retardants save lives Many classes of FRs  BFRs most cost effective >75 different BFRs  Br-BPs, BDEs, CDs, phenols, phthalates,++ Global, transboundary problem Persistence Potential for bioaccumulation Limited data base

3. TBBPA Extensive Ongoing Studies under “FIRE”

4. HBCD Persistent; Bioaccumulative; Potentially Toxic Science Needs  Exposure Information  Toxicity Studies

5. HBCD in 30 Canadian Human Milks (ppb lipid) (Ryan and Patry, 2002) MeanMedianMinMax 6.61.30126

6. PBDEs Penta and Octa No longer produced in US, but continued use allowed Persistence and bioaccumulation --  continuing concern

7. Penta and Octa Science Questions How are the congeners getting into the environment? Environmental fate and transport? Pathways of human exposure  Dust>Diet??? Modes of action for toxic effects

8. BDE Structures BDE 100 BDE 47 BDE 99 BDE 153

9. Commercial Mixture vs. Humans Media BDE Congeners (%) 4799100153154 Commercial PentaBDE 3748843 Human Tissue54148204 Hites 2004 WHY THE DIFFERENCE? Environmental degradation/debromination? Altered toxicokinetics?  Are most people like mice or rats?

10. Deca High volume product Worldwide presence PPM concentrations in sediment PPB concentrations in biota

11. Deca Science Questions Deca Breakdown  Photolytically  Microbially  Metabolically Is Deca (BDE209) itself toxic? What about Deca Metabolites/ Breakdown Products?

12. Potential Health Risk of PBDEs Margin of exposure for PBDEs appears low Additional concerns:  Are PBDEs interacting with other PBTs?  Contamination with Brominated Dioxins/Furans