Table of Contents

Component Description

Flame retardants (FRs) are either additive or reactive ingredients applied to household and consumer products to reduce the products flammability, and to meet state and federal fire safety standards and regulations. Until recently, a dominant class of FR additives used for household products was polybrominated diphenyl ethers (PBDEs), which are persistent and can accumulate in the environment (de Wit 2002; Law et al.2006, Stapleton et al. 2012). Flame retardant formulations containing chlorinated and non-chlorinated organophosphates and non-PBDE brominated chemicals have entered consumers’ markets as PBDEs have been phased-out in many countries (van der Veen and de Boer 2012).  Some of these non-PBDE compounds used in flame retardant formulations are: triphenyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(1-chloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tri-cresyl phosphates, tributyl phosphate, tribenzyl phosphate, and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate. We recently developed a method to measure metabolites of these compounds that can be used as exposure biomarkers: diphenyl phosphate, bis(1,3-dichloro-2-propyl) phosphate), bis(1-chloro-2-propyl) phosphate, bis(2-chloroethyl) phosphate, di-cresyl phosphates, dibutyl phosphate, dibenzyl phosphate, and 2,3,4,5-tetrabromobenzoic acid. 

Eligible Sample

One-third subsample of participants aged 6+ years from NHANES 2011-2012 with stored urine.

Description of Laboratory Methodology

The method uses 0.2 mL urine and is based on enzymatic hydrolysis of urinary conjugates of the target analytes, automated off-line solid phase extraction, reversed phase high-performance liquid chromatography separation, and isotope dilution-electrospray ionization tandem mass spectrometry detection (Jayatilaka et al. 2019.

Laboratory Quality Assurance and Monitoring

The analytical measurements were conducted following strict quality control/quality assurance CLIA guidelines. Along with the study samples, each analytical run included high- and low-concentration quality control materials (QCs) and reagent blanks to assure the accuracy and reliability of the data. The concentrations of the high-concentration QCs and the low-concentration QCs, averaged to obtain one measurement of high-concentration QC and low-concentration QC for each run, were evaluated using standard statistical probability rules (Caudill et al. 2008).

Data Processing and Editing

Data were received after all analyses were complete. The data were not edited. 

Data Access: All data are publicly available.

Analytic Notes

Detection Limits

The detection limits were constant for all of the analytes in the data set. Two variables are provided for each analyte. The variable name ending in “L” (ex., SSDPHPL) indicates whether the result was below the limit of detection: the value “0” means that the result was at or above the limit of detection, “1” indicates that the result was below the limit of detection. For analytes with analytic results below the limit of detection (ex., SSDPHPL=1), an imputed fill value was placed in the analyte results field. This value is the limit of detection divided by square root of 2 (LOD/√2). The other variable prefixed SS (ex., SSDPHP) provides the analytic result for that analyte.

The limits of detection (LOD, in µg/L) for DPhP, BDCPP, BCPP, BCEtP, DCP, DBuP, DBzP and TBBA are:

Variable Name

SAS Label

LOD

SSDPHP

Diphenyl phosphate (µg/L)

0.10

SSBDCPP

Bis(1,3-dichloro-2-propyl) phosphate (µg/L)

0.10

SSBCPP

Bis(1-chloro-2-propyl) phosphate (µg/L)

0.10

SSBCEP

Bis(2-chloroethyl) phosphate (µg/L)

0.10

SSDCP

Di-cresyl phosphates (µg/L)

0.50

SSDBUP

Dibutyl phosphate (µg/L)

0.10

SSDBZP

Dibenzyl phosphate (µg/L)

0.05

SSTBBA

2,3,4,5-tetrabromobenzoic acid (µg/L)

0.05

 

Interferences:

Blanks in an analyte results field represent missing values in cases when the presence of interferences precluded obtaining a valid numeric result.


References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 6 YEARS - 150 YEARS

SSDPHP - Diphenyl phosphate (ug/L)

Variable Name:
SSDPHP
SAS Label:
Diphenyl phosphate (ug/L)
English Text:
Diphenyl phosphate (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 179 Range of Values 2425 2425
. Missing 3 2428

SSDPHPL - Diphenyl phosphate cmt code

Variable Name:
SSDPHPL
SAS Label:
Diphenyl phosphate cmt code
English Text:
Diphenyl phosphate cmt code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2265 2265
1 Below lower detection limit 163 2428
. Missing 0 2428

SSBDCPP - Bis(1,3-dichloro-2-propyl) phos (ug/L)

Variable Name:
SSBDCPP
SAS Label:
Bis(1,3-dichloro-2-propyl) phos (ug/L)
English Text:
Bis(1,3-dichloro-2-propyl) phos (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 70.1 Range of Values 2416 2416
. Missing 12 2428

SSBDCPPL - Bis(1,3-dichloro-2-propyl) phos cmt cd

Variable Name:
SSBDCPPL
SAS Label:
Bis(1,3-dichloro-2-propyl) phos cmt cd
English Text:
Bis(1,3-dichloro-2-propyl) phos cmt cd
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2285 2285
1 Below lower detection limit 143 2428
. Missing 0 2428

SSBCPP - Bis(1-chloro-2-propyl) phosphate (ug/L)

Variable Name:
SSBCPP
SAS Label:
Bis(1-chloro-2-propyl) phosphate (ug/L)
English Text:
Bis(1-chloro-2-propyl) phosphate (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 17.9 Range of Values 2410 2410
. Missing 18 2428

SSBCPPL - Bis(1-chloro-2-propyl) phosphate cmt cd

Variable Name:
SSBCPPL
SAS Label:
Bis(1-chloro-2-propyl) phosphate cmt cd
English Text:
Bis(1-chloro-2-propyl) phosphate cmt cd
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1373 1373
1 Below lower detection limit 1055 2428
. Missing 0 2428

SSBCEP - Bis(2-chloroethyl) phosphate (ug/L)

Variable Name:
SSBCEP
SAS Label:
Bis(2-chloroethyl) phosphate (ug/L)
English Text:
Bis(2-chloroethyl) phosphate (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 72.4 Range of Values 2409 2409
. Missing 19 2428

SSBCEPL - Bis(2-chloroethyl) phosphate cmt cd

Variable Name:
SSBCEPL
SAS Label:
Bis(2-chloroethyl) phosphate cmt cd
English Text:
Bis(2-chloroethyl) phosphate(µg/L)cmt cd
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2078 2078
1 Below lower detection limit 350 2428
. Missing 0 2428

SSDCP - Di-cresyl phosphates (ug/L)

Variable Name:
SSDCP
SAS Label:
Di-cresyl phosphates (ug/L)
English Text:
Di-cresyl phosphates (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.354 to 1.63 Range of Values 2422 2422
. Missing 6 2428

SSDCPL - Di-cresyl phosphates cmt code

Variable Name:
SSDCPL
SAS Label:
Di-cresyl phosphates cmt code
English Text:
Di-cresyl phosphates (µg/L) cmt code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 11 11
1 Below lower detection limit 2417 2428
. Missing 0 2428

SSDBUP - Dibutyl phosphate (ug/L)

Variable Name:
SSDBUP
SAS Label:
Dibutyl phosphate (ug/L)
English Text:
Dibutyl phosphate (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 12.5 Range of Values 2403 2403
. Missing 25 2428

SSDBUPL - Dibutyl phosphate cmt code

Variable Name:
SSDBUPL
SAS Label:
Dibutyl phosphate cmt code
English Text:
Dibutyl phosphate cmt code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 933 933
1 Below lower detection limit 1495 2428
. Missing 0 2428

SSDBZP - Dibenzyl phosphate (ug/L)

Variable Name:
SSDBZP
SAS Label:
Dibenzyl phosphate (ug/L)
English Text:
Dibenzyl phosphate (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.035 to 0.103 Range of Values 2425 2425
. Missing 3 2428

SSDBZPL - Dibenzyl phosphate cmt code

Variable Name:
SSDBZPL
SAS Label:
Dibenzyl phosphate cmt code
English Text:
Dibenzyl phosphate cmt code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 6 6
1 Below lower detection limit 2422 2428
. Missing 0 2428

SSTBBA - 2,3,4,5-tetrabromobenzoic acid (ug/L)

Variable Name:
SSTBBA
SAS Label:
2,3,4,5-tetrabromobenzoic acid (ug/L)
English Text:
2,3,4,5-tetrabromobenzoic acid (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.035 to 2.79 Range of Values 2427 2427
. Missing 1 2428

SSTBBAL - 2,3,4,5-tetrabromobenzoic acid cmt cd

Variable Name:
SSTBBAL
SAS Label:
2,3,4,5-tetrabromobenzoic acid cmt cd
English Text:
2,3,4,5-tetrabromobenzoic acid cmt cd
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 134 134
1 Below lower detection limit 2294 2428
. Missing 0 2428

WTSB2YR - 1/3 subsample weights

Variable Name:
WTSB2YR
SAS Label:
1/3 subsample weights
English Text:
1/3 subsample weights
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
14032.338381 to 649694.78163 Range of Values 2428 2428
. Missing 0 2428