Due to the voluntary withdrawals and/or bans on the use of two polybrominated diphenyl
ether (PBDE) commercial mixtures, an increasing number of alternate flame retardant
chemicals are being introduced in commercial applications. To determine if these alternate
BFRs are present in indoor environments, we analyzed dust samples collected from 19
homes in the greater Boston, MA area during 2006. Using pure and commercial standards
we quantified the following brominated flame retardant chemicals using GC/ECNI-MS
methods: hexabromocyclododecane (sigma HBCD), bis(2,4,6,-tribromphenoxy)ethane (BTBPE),
decabromodiphenyl ethane (DBDPE), and the brominated components found in Firemaster
550 (FM 550): 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) and (2-ethylhexyl)tetrabromophthalate
(TBPH), the latter compound being a brominated analogue of di(2-ethylhexyl)phthalate
(DEHP). The concentrations of all compounds were log-normally distributed and the
largest range in concentrations was observed for HBCD (sum of all isomers), with concentrations
ranging from <4.5 ng/g to a maximum of 130,200 ng/g with a median value of 230 ng/g.
BTBPE ranged from 1.6 to 789 ng/g with a median value of 30 ng/g and DBDPE ranged
from <10.0 to 11,070 ng/g with a median value of 201 ng/g. Of the FM 550 components,
TBB ranged from <6.6 to 15,030 ng/g with a median value of 133 ng/g; whereas TBPH
ranged from 1.5 to 10,630 ng/g with a median value of 142 ng/g. Furthermore, the ratio
of TBB/TBPH present in the dust samples ranged from 0.05 to 50 (average 4.4), varying
considerably from the ratio observed in the FM 550 commercial mixture (4:1 by mass),
suggesting different sources with different chemical compositions, and/or differential
fate and transport within the home. Analysis of paired dust samples collected from
different rooms in the same home suggests HBCD, TBB, and TBPH are higher in dust from
the main living area compared to dust collected in bedrooms; however, BTBPE and DBDPE
levels were comparable between rooms. This study highlights the fact that numerous
types of brominated flame retardants are present in indoor environments, raising questions
about exposure to mixtures of these contaminants.