Interlaboratory comparison investigations (ICIs) and external quality assurance schemes (EQUASs) for flame retardant analysis in biological matrices: Results from the HBM4EU project

The European Human Biomonitoring Initiative (HBM4EU) is coordinating and advancing human biomonitoring (HBM). For this purpose, a network of laboratories delivering reliable analytical data on exposure fundamental. comparability accuracy analysing flame retardants (FRs) in serum urine were investigated by quality assurance/quality control (QA/QC) scheme comprising interlaboratory comparison investigations (ICIs) external assurance schemes (EQUASs). This paper presents the evaluation process discusses results four ICI/EQUAS rounds performed from 2018 to 2020 for determination ten halogenated (HFRs) represented three congeners polybrominated diphenyl ethers (BDE-47, BDE-153 BDE-209), two isomers hexabromocyclododecane (?-HBCD ?-HBCD), dechloranes (anti-DP syn-DP), tetrabromobisphenol A (TBBPA), decabromodiphenylethane (DBDPE), 2,4,6-tribromophenol (2,4,6-TBP) serum, metabolites organophosphorus (OPFRs) urine, at concentration levels. number satisfactory reported increased during rounds. In case HFRs, scope participating varied substantially (from ten) most cases did not cover entire target spectrum chemicals. highest participation rate was reached BDE-47 BDE-153. majority participants achieved more than 70% these compounds over all other percentage successful 44 100%. TBBPA, DBDPE, 2,4,6-TBP possible because too small. Only seven participated OPFR five them least biomarkers. Nevertheless, laboratory performance using Z-scores first required an alternative approach compared HFRs small high variability experts' results. obtained within programme showed significant core comparable HBM BDE-47, BDE-153, BDE-209, ?-HBCD, ?-HBCD, anti-DP, syn-DP. On hand, revealed critically low capacity Europe as well