Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame retardant mixture Firemaster® 550.
BACKGROUND
Firemaster® 550 (FM550) is commonly added to residential furniture to reduce its flammability. Recent toxicological evidence suggests that FM550 may be endocrine disrupting and obesogenic.


OBJECTIVE
Our objectives were to develop methods to assess exposure to FM550 in human populations and to identify potential routes of exposure.


METHODS
Using mass spectrometry methods, we developed a method to measure 2,3,4,5-tetrabromobenzoic acid (TBBA), a urinary metabolite of the major brominated FM550 component 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB). The method was applied to a cohort of adult volunteers (n = 64). Participants completed questionnaires, provided urine and handwipe samples, and collected dust samples from their homes. We measured TBB and the other major brominated FM550 component, bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), in paired dust and handwipe samples.


RESULTS
TBBA was detected in 72.4% of urine samples. Although TBBA is a rapidly formed metabolite, analyses indicated moderate temporal reliability (interclass correlation coefficient = 0.56; 95% confidence interval: 0.46, 0.66). TBB and TBPH were detected frequently in dust samples [geometric mean (GM) = 315.1 and 364.7 ng/g, respectively] and in handwipes (GM = 31.4 and 23.4 ng, respectively). Levels of TBB and TBPH in dust were positively correlated with levels in handwipes. In addition, levels of TBB in handwipes were positively correlated with urinary TBBA. Results suggest frequent hand washing may reduce the mass of TBB on participants' hands and reduce urinary TBBA levels.


CONCLUSIONS
Cumulatively, our data indicate that exposures to FM550 are widespread and that the home environment may be an important source of exposure. Urinary TBBA provides a potentially useful biomarker of FM550 exposure for epidemiologic studies.
Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
Kate
K
Hoffman
Mingliang
M
Fang
Brian
B
Horman
Heather B
HB
Patisaul
Stavros
S
Garantziotis
Linda S
LS
Birnbaum
Heather M
HM
Stapleton
D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001970:Bromobenzoates / Q000652:urine; D004391:Dust / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D004785:Environmental Pollutants / Q000652:urine*; D005260:Female; D005411:Flame Retardants / Q000378:metabolism*; D006225:Hand; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D010755:Organophosphates / Q000652:urine*; D010795:Phthalic Acids / Q000652:urine; D011075:Polybrominated Biphenyls / Q000652:urine*; D051381:Rats
D015415:Biomarkers; D001970:Bromobenzoates; D004391:Dust; D004785:Environmental Pollutants; C000591741:Firemaster 550; D005411:Flame Retardants; D010755:Organophosphates; D010795:Phthalic Acids; D011075:Polybrominated Biphenyls; C576262:bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate