Tris(2-ethylhexyl) phosphate

Health surveillance data

Administrative data

Endpoint:

health surveillance data

Type of information:

experimental study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

publication

Title:

Spatial occurrence and composition profile of organophosphate esters (OPEs) in farmland soils from different regions of China: Implications for human exposure

Author:

Qin Zhang et al.,

Year:

2011

Bibliographic source:

Environmental Pollution 276 (2021) 116729

Materials and methods

Study type:

biological exposure monitoring

Endpoint addressed:

other: Health risk exposure to OPEs in farmland soils was examined for non-carcinogenic risk to children and for carcinogenic risk to adults at the present detected concentrations.

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In this study, the spatial occurrence, composition profile and health risk of 13 OPE species in farmland soils from four provinces of China were characterized.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tris(2-ethylhexyl)phosphate

IUPAC Name:

Tris(2-ethylhexyl)phosphate

Method

Type of population:

general

Ethical approval:

no

Details on study design:

In this study, the spatial occurrence, composition profile, potential source and human health risk of OPEs in farmland soils were investigated in four provincial regions of China. Alkyl-, Cl- and aryl-OPEs were ubiquitously detected in farmland soils.
Human health risks from exposure to OPEs in soil mainly occur by three exposure routes, namely ingestion, inhalation and dermal contact. Chronic daily intake (CDI) values of OPEs in soil for three age groups (children, teens and adults) were calculated. Non-carcinogenic and carcinogenic risks were further assessed based on the calculated hazard index (HI) and carcinogenic risk (CR) values. An HI value of <1.0 is regarded as an acceptable risk for non-carcinogenicity, while a CR
value < 1.0 E-6 is regarded as insignificant carcinogenicity.

Results and discussion

Results:

The concentrations (Summe of OPEs ranged from 62.3 to 394 ng/g dw), with a median of 229 ng/g dw (mean: 230 ng/g dw). Among the OPEs, alkyl-OPEs showed the highest median concentrations (152, 16 - 210 ng/g dw), followed by Cl-OPEs (29.3, 4.32 - 158 ng/g dw) and aryl-OPEs (22.8, 2.99 135 ng/g dw). For individual OPEs, TEHP was found as the predominant species in soils with a median value of 143 ng/g dw, followed by TCP (20.8 ng/g dw) and TCEP (17.9 ng/g dw).

Based on the available reference doses (RfDs) for ten OPEs, the average non-carcinogenic risk (50th percentile) of the OPEs (Summe HI) was 4.87 x 10E-6, 3.35 x 10E-6 and 1.60 x 10E-6 for children, teens and adults, respectively; while high risk (95th percentile) was 1.20 x 10 E-5, 8.05 x 10E-6 and 4.27 x 10 E-6 for children, teens and adults, respectively. These values are about five to six orders of magnitude lower than the acceptable limit value.

The average carcinogenic risk (50th percentile) of the OPEs (Summe CR) was 1.34 x 10E-10, 5.00 x 10E-11 and 2.13 x 10E-10 for children, teens and adults, respectively; while high risk (95th percentile) was 3.81 x 10 E-10, 1.39 x 10 E-10 and 6.47 x 10 E-10 for children, teens and adults based on the available carcinogenic slope factors (SFOs) for five OPEs. These were consistently four to five orders of magnitude under the threshold limit.

Any other information on results incl. tables

Health risk exposure to OPEs was at an acceptable level at the current concentrations. However, TCEP accounted for more than 40% of the non-carcinogenic risk, and more than 50% of the carcinogenic risk of the total risk of OPEs, which should be paid more attention, along with TEHP.

Applicant's summary and conclusion

Conclusions:

Overall, OPEs in farmland soils do not seem to pose a serious threat to human health at the current level.

Executive summary:

The environmental load of organophosphate ester (OPE) flame retardants has caused a series of problems due to their extensive use. The soil matrix, as an ultimate sink for organic pollution, plays a vital part in the fate of OPEs in the environment. In this study, the spatial occurrence, composition profile and health risk of 13 OPE species in farmland soils from four provinces of China were characterized. Excluding tris(2,3-dibromopropyl) phosphate (TDBPP) and ethylhexyl diphenyl phosphate (EHDPP), the remaining eleven OPEs had a high detection frequency (DF) ranging from 60% to 100%. The range of total OPE (Summe OPE) concentrations were 62.3 - 394 ng/g dry weight (dw), with a median of 228 ng/g dw.

 

Among these OPEs, tris(2-ethylhexyl) phosphate (TEHP) with a median of 143 ng/g dw) was the predominant species, followed by tricresyl phosphate (TCP; median of 20.1 ng/g dw) and tris(2-chloroethyl) phosphate (TCEP; median of 17.9 ng/g dw). In terms of geographical distribution, significantly lower OPEs levels were found in samples from Heilongjiang (159 ± 47.0 ng/g dw) than in those of Guangxi (264 ± 66.0 ng/g dw), Henan (252 ± 74.5 ng/g dw) and Hubei (242 ± 52.8 ng/g dw) provinces. Principal component analysis and Spearman’s correlations were used to reveal potential sources of OPEs in the different provincial regions.

 

Health risk exposure to OPEs in farmland soils was at an acceptable level (<1.20 x 10 E-5 for non-carcinogenic risk to children as the most sensitive age group; and <6.47 x 10 E-10 for carcinogenic risk to adults as the most sensitive age group) at the present detected concentrations.