• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Laboratory Quality Assurance and Monitoring
• Data Processing and Editing
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • WTSSBI2Y - Surplus specimen B 15-16 2 year weights
  • SSDPHP - Diphenyl phosphate (ug/L)
  • SSDPHPL - Diphenyl phosphate (ug/L) cmt code
  • SSBDCPP - Bis(1,3-dichloro-2-propyl) phos(ug/L)
  • SSBDCPPL - Bis(1,3dichloro-2propyl)phos(ug/L)cmt cd
  • SSBCPP - Bis(1-chloro-2-propyl) phosphate (ug/L)
  • SSBCPPL - Bis(1chloro-2propyl) phosp(ug/L) cmt cd
  • SSBCEP - Bis(2-chloroethyl) phosphate (ug/L)
  • SSBCEPL - Bis(2-chloroethyl) phosphate(ug/L)cmt cd
  • SSDCP - Di-cresyl phosphates (ug/L)
  • SSDCPL - Di-cresyl phosphates (ug/L) cmt code
  • SSDBUP - Dibutyl phosphate (ug/L)
  • SSDBUPL - Dibutyl phosphate (ug/L) cmt code
  • SSDBZP - Dibenzyl phosphate (ug/L)
  • SSDBZPL - Dibenzyl phosphate (ug/L) cmt code
  • SSTBBA - 2,3,4,5-tetrabromobenzoic acid (ug/L)
  • SSTBBAL - 2,3,4,5tetrabromobenzoicacid(ug/L)cmt cd
  • SSIPPP - 2(isopropyl)phenyl)phenyl phosphateug/L
  • SSIPPPL - 2(isopropyl)phenyl)phenyl phosphate cd
  • SSBPPP - 4(tert-butyl)phenyl)phenyl phosphateug/L
  • SSBPPPL - 4(tert-butyl)phenyl)phenyl phosphate cd

National Health and Nutrition Examination Survey

2015-2016 Data Documentation, Codebook, and Frequencies

Flame Retardants - Urine (Surplus) (SSFR_I)

Data File: SSFR_I.xpt

First Published: July 2022

Last Revised: NA

Component Description

Flame retardants (FRs) are either additive or reactive ingredients applied to household and consumer products to reduce the product’s 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 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, isopropyl triphenyl phosphates, tertbutyltriphenyl phosphates, 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, 2-((isopropyl)phenyl)phenyl phosphate (¡PPPP), 4-((tert-butyl)phenyl)phenyl phosphate (tBPPP), and 2,3,4,5-tetrabromobenzoic acid.

Eligible Sample

A full sample of participants aged 3 to 5 years and a one-third subsample of participants aged 6 years and older, who gave consent for their samples to be used in future research and had stored urine samples from 2015-2016, were eligible.

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 (QCMs) and reagent blanks to assure the accuracy and reliability of the data. The concentrations of the high-concentration QCMs and the low-concentration QCMs, averaged to obtain one measurement of high-concentration QCM and low-concentration QCM 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.

Analytic Notes

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

Special Subsample Weights

Special subsample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data (WTSSBI2Y).

Demographic and Other Related Variables

The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2015-2016 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic data file.

This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).

The variable URXUCR (urine creatinine) will not be reported in this file. URXUCR can be found in the data file titled “Albumin & Creatinine – Urine”.

Detection Limits

The detection limits varied for the analytes in the data set. Two variables are provided for each of these analytes. 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. The other variable (ex., SSDPHP) provides the analytic result for that analyte. 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 lower limit of detection divided by square root of 2 (LLOD/sqrt[2]).

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

 

Interferences:

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

References

• Caudill SP, Schleicher RL, Pirkle JL. (2008). Multi-rule quality control for the age-related eye disease study. Statist Med 27: 4094-4106.
  
• de Wit CA (2002). An overview of brominated flame retardants in the environment. Chemosphere 46 (5):583-624.
  
• Jayatilaka NK, Restrepo P, Davis, Z, Vidal M, Calafat AM. Ospina M. (2019). Quantification of 16 urinary biomarkers of exposure to flame retardants, plasticizers, and organophosphate insecticides for biomonitoring studies. Chemosphere 235:481-491.
  
• Law RJ, Allchin CR, de Boer J, Covaci A, Herzke D, Lepom P, et al. (2006). Levels and trends of brominated flame retardants in the European environment. Chemosphere 64:187–208.
  
• Stapleton HM, Sharma S, Getzinger G, Ferguson PL, Gabriel M, Webster TF, Blum A (2012). Novel and High Volume Use Flame Retardants in US Couches Reflective of the 2005 PentaBDE Phase Out. Environmental Science & Technology 46 (24):13432-13439.
  
• van der Veen I, de Boer J (2012). Phosphorus flame retardants: Properties, production, environmental occurrence, toxicity and analysis. Chemosphere 88 (10):1119-1153.
  

Codebook and Frequencies