HBM4EU ICI EQUAS report BFR in serum round 1

Within the frame of the HBM4EU project, an ICI was organised on the determination of 10 BFR biomarkers in serum. In total 12 laboratories from 9 EU countries registered and 11 laboratories submitted results. In June 2018, each participant received three tubes of control materials of human serum at 3 different levels. The biomarker concentrations were mostly in the range 0.05-0.5 μg/L and 0.25-11 μg/L for level 1 and level 2, respectively. Homogeneity and stability of the control material were tested. In total six consensus value and Z-scores could be determined for BDE 47 (level 1 and level 2), for BDE 153 (level 1 and level 2) and for BDE 209 (level 1 and level 2). The ICI-RSDR varied from 27% to 159%, exceeding the FFP-RSDR in all cases. For α-HBCD, γ-HBCD, DP-syn, DP-anti, 2,4,6-TBP and TBBPA no assigned values and Z-scores could be determined due to a limited number of obtained results. The number of BFRs covered by the different laboratories varied widely from 3 to all 10 target biomarkers. Two biomarkers (BDE 47 and BDE 153) were measured by 10 laboratories, BDE 209 was measured by 9 laboratories, others were analysed by 2 to 6 labs. Out of 10 laboratories, 90% reach an acceptable score for BDE 47 at both levels and 80% for BDE 153 at both level. For BDE 153, 80% laboratories provide the acceptable score. For BDE 209 more than 75% of the acceptable z-score was achieved.