1,4-naphthoquinone

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017

Reliability:

2 (reliable with restrictions)

Justification for type of information:

Acceptable calculation method. Meets generally accepted scientific standards, well documented and acceptable for assessment.

Qualifier:

according to guideline

Guideline:

other: Guidance on information requirements and chemical safety assessment, Chapter R.6: QSARs and grouping of chemicals, ECHA, 2008

Deviations:

not applicable

Principles of method if other than guideline:

The bioconcentration factor (BCF) of 1,4-Naphthoquinone was calculated by the EPI (Estimation Programs Interface) Suite™, a Windows®-based suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC).

The included program BCFBAF estimates the BCF of an organic compound using the compound's log Kow. Substances are classified either as ionic or non-ionic and are divided into 3 classes of log Kow ranges:
log Kow <1
log Kow 1 - 7
log Kow > 7

For each range a best-fit refgression was performed using a training dataset. The BCF of substances with log Kow can be described as:

log BCF = 0.6598 log Kow + Σ correction factors

The correction factors are based on specific structural features.

In addition the bioconcentration factor BCF and the bioaccumulation factor BAF are estimated using the Arnot-Gobas estimation methology. The model consists of the development of a bioaccumulation model, the parameterisation of the model to reflect Canadian conditions and the calibration of the model to a large BCF and BAF database.
The model gives a prediction for non-ionic organic chemicals in three general trophic fish levels (lower, middle, upper) in temperate environments and includes mechanistic processes for bioconcentration and bioaccumulation (e.g uptake/elimination at the gill surface, fecal egestion). The model requires the log Kow and the biotransformation rate constant (k,mn/day) as input parameters.
The BAF calculations are derived from large datasets of measured BCF's (Great Lakes).
The model is calibrated to each trophic level of measured BAF values thus providing estimates that are in general agreement with measured BAFs, thus capturing the overall food web biomagnification potential of chemicals in aquatic food webs for screening assessments.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Details on sampling:

not applicable

Details on preparation of test solutions, spiked fish food or sediment:

not applicable

Test organisms (species):

other: not applicable

Details on test organisms:

not applicable

Route of exposure:

other: not applicable

Test type:

other: BCF modelling

Hardness:

not applicable

Test temperature:

not applicable

pH:

not applicable

Dissolved oxygen:

not applicable

TOC:

not applicable

Salinity:

not applicable

Details on test conditions:

not applicable

Nominal and measured concentrations:

not applicable

Type:

BCF

Value:

1.622 L/kg

Basis:

whole body w.w.

Remarks on result:

other: regression-based estimate

Type:

BCF

Value:

5.856 L/kg

Basis:

whole body w.w.

Calculation basis:

other: not applicable

Remarks on result:

other: Arnot-Gobas model (upper trophic)

Type:

BAF

Value:

5.856 L/kg

Basis:

whole body w.w.

Calculation basis:

other: not applicable

Remarks on result:

other: Arnot-Gobas model (upper trophic)

Details on kinetic parameters:

not applicable

Metabolites:

not applicable

Results with reference substance (positive control):

not applicable

Reported statistics:

not applicable

Bioaccumulation Estimates (BCFBAF v3.01):

Log BCF from regression-based method = 0.210 (BCF = 1.622 L/kg wet-wt)

Log Biotransformation Half-life (HL) = -0.4442 days (HL = 0.3596 days)

Log BCF Arnot-Gobas method (upper trophic) = 0.768 (BCF = 5.856)

Log BAF Arnot-Gobas method (upper trophic) = 0.768 (BAF = 5.856)

log Kow used: 1.71 (expkow database)

 

Conclusions:

The BCF of 1,4-Naphthoquinone was predicted by BCFBAF v3.01 to be 1.622 L/kg.

Executive summary:

Data is available from a reliable QSAR model.

Bioaccumulation of 1,4-Naphthoquinone not expected since the criterion for considering substances as being not bioaccumulative (i.e. unlikely to have a BCF > 2,000) are met as can be derived from BCF calculation.No further testing is required.

Description of key information

The bioconcentration factor (BCF) of 1,4-Naphthoquinone was calculated by  the EPI (Estimation Programs Interface) Suite™, a Windows®-based suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC).

Following results for the bioconcentration factor BCF (L/kg wet weight; upper, mid and lower trophic level) were obtained:

Bioaccumulation Estimates (BCFBAF v3.01):

Log BCF from regression-based method = 0.210 (BCF = 1.622 L/kg wet-wt)

Log Biotransformation Half-life (HL) = -0.4442 days (HL = 0.3596 days)

Log BCF Arnot-Gobas method (upper trophic) = 0.768 (BCF = 5.856)

Log BAF Arnot-Gobas method (upper trophic) = 0.768 (BAF = 5.856)

log Kow used: 1.71 (expkow database)

Key value for chemical safety assessment

BCF (aquatic species):

1.622 L/kg ww

Additional information

Data is available from a reliable QSAR model.

Bioaccumulation of 1,4 -Naphthoquinone is not expected since the criterion for considering substances as being not bioaccumulative (i.e. unlikely to have a BCF > 2,000) are met as can be derived from BCF calculation. No further testing is required.