Table of Contents

Locator Record

Title: Urinary Phthalates (PHTHTE_E )
Contact Number: 1-866-441-NCHS
Years of Content: 2007 - 2008
First Published: October, 2010
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Urinary Phthalates
Record Source: NHANES 2007 - 2008
Survey Methodology: NHANES 2007 - 2008 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

Phthalate acid esters (phthalates) have been used extensively as plasticizers in a wide range of applications such as children’s toys, food packaging, personal care products, and medical supplies. Because some of these compounds have been shown to bind to estrogen receptors and have been associated with estrogenic effects in laboratory animals, increasing concerns have been expressed about phthalate usage in food packaging materials, personal care products, and children’s toys. Measurement of urinary phthalate metabolites in humans is useful to evaluate recent exposure and potential human health effects from these chemicals.

Eligible Sample

Participants aged 6 years and older who met the subsample requirements

Description of Laboratory Methodology

The test principle utilizes high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) for the quantitative detection in urine of the following phthalate metabolites: monomethyl phthalate (mMP), monoethyl phthalate (mEP), monobutyl phthalate (mBP), mono-isobutyl phthalate (miBP), mono (3-carboxypropyl) phthalate (mCPP), monocyclohexyl phthalate (mCHP), mono(2-ethylhexyl) phthalate (mEHP), monooctyl phthalate (mOP), monobenzyl phthalate (mBzP), monoisononyl phthalate (mNP), mono(2-ethyl-5-oxohexyl) phthalate (mEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), mono(2-ethyl-5-carboxypentyl) phthalate (mECPP), monocarboxyoctyl phthalate (MCOP), and monocarboxynonyl phthalate (MCNP) (Kato, K., et al., 2005). Urine samples are processed using enzymatic deconjugation of the glucuronidated phthalate monoesters followed by on-line solid phase extraction (SPE) coupled with reversed phase HPLC-ESI-MS/MS. Assay precision is improved by incorporating isotopically-labeled internal standards of the phthalate metabolites. In addition, 4-methyl umbelliferone glucuronide is used to monitor deconjugation efficiency. This selective method allows for rapid detection of monoester metabolites of commonly used phthalate diesters in human urine with limits of detection in the low ng/mL range.

Laboratory Quality Assurance and Monitoring

Urine specimens are processed, stored, and shipped to the Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention for analysis.

Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Vials are stored under appropriate frozen (–20°C) conditions until they are shipped to National Center for Environmental Health for testing.

Mobile Examination Centers (MECs)

Laboratory team performance is monitored using several techniques. NCHS and contract consultants use a structured quality assurance evaluation during unscheduled visits to evaluate both the quality of the laboratory work and the quality-control procedures. Each laboratory staff person is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.

The NHANES QA/QC protocols meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the laboratories. In the MEC, these methods include performing blind split samples collected on “dry run” sessions. In addition, contract laboratories randomly perform repeat testing on 2.0% of all specimens.

NCEH developed and distributed a quality control protocol for all the laboratories which outlined the Westgard rules used when running NHANES specimens. Any problems encountered during shipping or receipt of specimens, instrument calibration, reagents, and any special considerations are submitted to NCHS and Westat. Summary statistics for each control pool, QC graphs, are reviewed by NCHS for trends or shifts in the data. The laboratories are required to explain any identified areas of concern.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet the Division of Laboratory Sciences’ quality control and quality assurance performance criteria for accuracy and precision (similar to specifications outlined by Westgard (Westgard J., et al., 1981).

Analytic Notes

Mono-ethyl phthalate (URXMEP), Mono-benzyl phthalate (URXMZP), Mono-n-octyl phthalate (URXMOP), Mono-isononyl phthalate (URXMNP), and Mono-cyclohexyl phthalate (URXMCP):
NHANES recently learned that analytical standards used since 1999 and used for several metabolites were of insufficient purity. As a result of further investigation, a correction factor was applied to each value for the 5 metabolites.

Subsample weights

Measures of urinary environmentals were measured in a one third subsample of persons 6 years and over. Special sample 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.

Variance estimation

The analysis of NHANES laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES Demographic Data File contains demographic and 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.

Links to NHANES Data Files

This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier SEQN.

Detection Limits

The detection limits were constant for all of the analytes in the data set.  Two variables are provided for each of these analytes.  The variable named URD___LC indicates whether the result was below the limit of detection.  There are two values: “0” and “1””.  “0” means that the result was at or above the limit of detection.   “1” indicates that the result was below the limit of detection.  In cases, where the result was below the limit of detection, the value for that variable is the detection limit divided by the square root of two.

The other variable named URX___ provides the analytic result for that analyte.

The lower limit of detections for the environmental phthalates are:

Analyte Item Id Limit of Detection(LLOD)
Mono(carboxyoctyl) phthalate URXCOP 0.7
Mono(carboxynonyl) phthalate URXCNP 0.5
Mono-2-ethyl-5-carboxypentyl phthalate URXECP 0.5
Mono-n-butyl phthalate (ng/mL) URXMBP 0.6
Mono-(3-carboxypropyl) phthalate (ng/mL) URXMC1 0.2
Mono-cyclohexyl Phthalate (ng/mL) URXMCP 0.603
Mono-ethyl phthalate (ng/mL) URXMEP 0.462
Mono-(2-ethyl-5-hydroxyhexyl) (ng/mL) URXMHH 0.7
Mono-(2-ethyl)-hexyl phthalate (ng/mL) URXMHP 1.1
Mono-isobutyl pthalate (ng/mL) URXMIB 0.3
Mono-n-methyl phthalate (ng/mL) URXMNM 1.1
Mono-isononyl phthalate (ng/mL) URXMNP 1.232
Mono-(2-ethyl-5-oxohexyl) (ng/mL) URXMOH 0.6
Mono-n-octyl phthalate (ng/mL) URXMOP 1.848
Mono-benzyl phthalate (ng/mL) URXMZP 0.216

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

WTSB2YR - Environmental B Two-year weights

Variable Name:
WTSB2YR
SAS Label:
Environmental B Two-year weights
English Text:
Environmental B Two-year weights
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 533131.16757 Range of Values 2718 2718
. Missing 0 2718

URXCNP - Mono(carboxynonyl) Phthalate (ng/mL)

Variable Name:
URXCNP
SAS Label:
Mono(carboxynonyl) Phthalate (ng/mL)
English Text:
Mono(carboxynonyl) Phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.35 to 651.4 Range of Values 2604 2604
. Missing 114 2718

URDCNPLC - Mono(carboxynonyl) Phthalate comment

Variable Name:
URDCNPLC
SAS Label:
Mono(carboxynonyl) Phthalate comment
English Text:
Mono(carboxynonyl) Phthalate comment 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 2355 2355
1 Below lower detection limit 249 2604
. Missing 114 2718

URXCOP - Mono(carboxyoctyl) Phthalate (ng/mL)

Variable Name:
URXCOP
SAS Label:
Mono(carboxyoctyl) Phthalate (ng/mL)
English Text:
Mono(carboxyoctyl) Phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.49 to 776.9 Range of Values 2604 2604
. Missing 114 2718

URDCOPLC - Mono(carboxyoctyl) Phthalate comment

Variable Name:
URDCOPLC
SAS Label:
Mono(carboxyoctyl) Phthalate comment
English Text:
Mono(carboxyoctyl) Phthalate comment 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 2510 2510
1 Below lower detection limit 94 2604
. Missing 114 2718

URXECP - Mono-2-ethyl-5-carboxypentyl phthalate

Variable Name:
URXECP
SAS Label:
Mono-2-ethyl-5-carboxypentyl phthalate
English Text:
Mono-2-ethyl-5-carboxypentyl phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.35 to 3412.5 Range of Values 2604 2604
. Missing 114 2718

URDECPLC - Mono-2ethyl5carboxypentyl phthalate cmt

Variable Name:
URDECPLC
SAS Label:
Mono-2ethyl5carboxypentyl phthalate cmt
English Text:
Mono-2-ethyl-5-carboxypentyl phthalate comment 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 2602 2602
1 Below lower detection limit 2 2604
. Missing 114 2718

URXMBP - Mono-n-butyl phthalate (ng/mL)

Variable Name:
URXMBP
SAS Label:
Mono-n-butyl phthalate (ng/mL)
English Text:
Mono-n-butyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.42 to 101013 Range of Values 2604 2604
. Missing 114 2718

URDMBPLC - Mono-n-butyl phthalate comment code

Variable Name:
URDMBPLC
SAS Label:
Mono-n-butyl phthalate comment code
English Text:
Mono-n-butyl phthalate comment 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 2585 2585
1 Below lower detection limit 19 2604
. Missing 114 2718

URXMC1 - Mono-(3-carboxypropyl) phthalate

Variable Name:
URXMC1
SAS Label:
Mono-(3-carboxypropyl) phthalate
English Text:
Mono-(3-carboxypropyl) phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.14 to 1425.8 Range of Values 2604 2604
. Missing 114 2718

URDMC1LC - Mono-(3-carboxypropyl) phthalate cmt

Variable Name:
URDMC1LC
SAS Label:
Mono-(3-carboxypropyl) phthalate cmt
English Text:
Mono-(3-carboxypropyl) phthalate comment 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 2542 2542
1 Below lower detection limit 62 2604
. Missing 114 2718

URXMCP - Mono-cyclohexyl phthalate (ng/mL)

Variable Name:
URXMCP
SAS Label:
Mono-cyclohexyl phthalate (ng/mL)
English Text:
Mono-cyclohexyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.4264 to 17.085 Range of Values 2604 2604
. Missing 114 2718

URDMCPLC - Mono-cyclohexyl phthalate comment code

Variable Name:
URDMCPLC
SAS Label:
Mono-cyclohexyl phthalate comment code
English Text:
Mono-cyclohexyl phthalate comment 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 112 112
1 Below lower detection limit 2492 2604
. Missing 114 2718

URXMEP - Mono-ethyl phthalate (ng/mL)

Variable Name:
URXMEP
SAS Label:
Mono-ethyl phthalate (ng/mL)
English Text:
Mono-ethyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.254 to 27970.14 Range of Values 2604 2604
. Missing 114 2718

URDMEPLC - Mono-ethyl phthalate comment code

Variable Name:
URDMEPLC
SAS Label:
Mono-ethyl phthalate comment code
English Text:
Mono-ethyl phthalate comment 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 2604 2604
1 Below lower detection limit 0 2604
. Missing 114 2718

URXMHH - Mono-(2-ethyl-5-hydroxyhexyl) phthalate

Variable Name:
URXMHH
SAS Label:
Mono-(2-ethyl-5-hydroxyhexyl) phthalate
English Text:
Mono-(2-ethyl-5-hydroxyhexyl) phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.49 to 3619 Range of Values 2604 2604
. Missing 114 2718

URDMHHLC - Mono(2ethyl5hydroxyhexyl) phthalate cmt

Variable Name:
URDMHHLC
SAS Label:
Mono(2ethyl5hydroxyhexyl) phthalate cmt
English Text:
Mono(2ethyl5hydroxyhexyl) phthalate cmt
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 2584 2584
1 Below lower detection limit 20 2604
. Missing 114 2718

URXMHP - Mono-(2-ethyl)-hexyl phthalate (ng/mL)

Variable Name:
URXMHP
SAS Label:
Mono-(2-ethyl)-hexyl phthalate (ng/mL)
English Text:
Mono-(2-ethyl)-hexyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.78 to 1252.7 Range of Values 2604 2604
. Missing 114 2718

URDMHPLC - Mono-(2-ethyl)-hexyl phthalate comment

Variable Name:
URDMHPLC
SAS Label:
Mono-(2-ethyl)-hexyl phthalate comment
English Text:
Mono-(2-ethyl)-hexyl phthalate comment 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 1746 1746
1 Below lower detection limit 858 2604
. Missing 114 2718

URXMNM - Mono-n-methyl phthalate

Variable Name:
URXMNM
SAS Label:
Mono-n-methyl phthalate
English Text:
Mono-n-methyl phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.78 to 10530 Range of Values 2604 2604
. Missing 114 2718

URDMNMLC - Mono-n-methyl phthalate comment code

Variable Name:
URDMNMLC
SAS Label:
Mono-n-methyl phthalate comment code
English Text:
Mono-n-methyl phthalate comment 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 1009 1009
1 Below lower detection limit 1595 2604
. Missing 114 2718

URXMNP - Mono-isononyl phthalate (ng/mL)

Variable Name:
URXMNP
SAS Label:
Mono-isononyl phthalate (ng/mL)
English Text:
Mono-isononyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.8712 to 214.83 Range of Values 2604 2604
. Missing 114 2718

URDMNPLC - Mono-isononyl phthalate comment code

Variable Name:
URDMNPLC
SAS Label:
Mono-isononyl phthalate comment code
English Text:
Mono-isononyl phthalate comment 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 284 284
1 Below lower detection limit 2320 2604
. Missing 114 2718

URXMOH - Mono-(2-ethyl-5-oxohexyl) phthalate

Variable Name:
URXMOH
SAS Label:
Mono-(2-ethyl-5-oxohexyl) phthalate
English Text:
Mono-(2-ethyl-5-oxohexyl) phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.42 to 1959.3 Range of Values 2604 2604
. Missing 114 2718

URDMOHLC - Mono-(2-ethyl-5-oxohexyl) phthalate cmt

Variable Name:
URDMOHLC
SAS Label:
Mono-(2-ethyl-5-oxohexyl) phthalate cmt
English Text:
Mono-(2-ethyl-5-oxohexyl) phthalate cmt
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 2560 2560
1 Below lower detection limit 44 2604
. Missing 114 2718

URXMOP - Mono-n-octyl phthalate (ng/mL)

Variable Name:
URXMOP
SAS Label:
Mono-n-octyl phthalate (ng/mL)
English Text:
Mono-n-octyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.3067 to 44.184 Range of Values 2604 2604
. Missing 114 2718

URDMOPLC - Mono-n-octyl phthalate comment code

Variable Name:
URDMOPLC
SAS Label:
Mono-n-octyl phthalate comment code
English Text:
Mono-n-octyl phthalate comment 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 23 23
1 Below lower detection limit 2581 2604
. Missing 114 2718

URXMZP - Mono-benzyl phthalate (ng/mL)

Variable Name:
URXMZP
SAS Label:
Mono-benzyl phthalate (ng/mL)
English Text:
Mono-benzyl phthalate (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1527 to 616.608 Range of Values 2604 2604
. Missing 114 2718

URDMZPLC - Mono-benzyl phthalate comment code

Variable Name:
URDMZPLC
SAS Label:
Mono-benzyl phthalate comment code
English Text:
Mono-benzyl phthalate comment 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 2558 2558
1 Below lower detection limit 46 2604
. Missing 114 2718

URXMIB - Mono-isobutyl phthalate

Variable Name:
URXMIB
SAS Label:
Mono-isobutyl phthalate
English Text:
Mono-isobutyl phthalate
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.21 to 724.4 Range of Values 2604 2604
. Missing 114 2718

URDMIBLC - Mono-isobutyl phthalate comment code

Variable Name:
URDMIBLC
SAS Label:
Mono-isobutyl phthalate comment code
English Text:
Mono-isobutyl phthalate comment 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 2557 2557
1 Below lower detection limit 47 2604
. Missing 114 2718

URXUCR - Creatinine, urine (mg/dL)

Variable Name:
URXUCR
SAS Label:
Creatinine, urine (mg/dL)
English Text:
Creatinine, urine (mg/dL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5 to 490 Range of Values 2623 2623
. Missing 95 2718