SUMILIZER GP

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

21 Sep - 09 Dec 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -I: Aqueous Exposure Bioconcentration Fish Test

Version / remarks:

02 Oct 2012

Deviations:

yes

Remarks:

See "Principles of methods if other than guideline"

Principles of method if other than guideline:

A dispersant was used for addition of the test substance into the test medium. As no water solubility was determined, it may be, that the concentration of test substance in test medium is higher than the maximum water solubility.
Only two fishes instead of four were sampled each sampling point.

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: The concentrations in fish for both levels were analyzed 4 times ; in weeks 2, 4, 6 and 8 (n=2). The control fish were analyzed at the initiation and the termination of exposure (n=2).
- Sampling intervals/frequency for test medium samples: The concentrations of the test substance in water for both level 1 and 2 were analyzed 16 times ; twice a week intervals (n=1).
- Sample storage conditions before analysis: Not specified
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):
Test water: For level 1 20 mL and for level 2 200 mL aliquot of was taken from each test tank and pretreated for high performance liquid chromatography (HPLC) analysis. The sampled water was filled up to 200 mL with recovery water (only level 1), 60 g sodium chloride and 50 mL hexane was added. After shaking for 5 min, the upper layer was filtrated and dehydrated using an IPS filter paper. Then it was concentrated to about 5 mL using a rotary evaporator about 40 °C and filled up to 10 mL with hexane.
Test organisms: Test fish were taken from each test tank and pretreated for HPLC analysis. Each fish was weighted and its body length was determined. Afterwards it was chopped into pieces, 80 mL Tetrahydrofuran was added. A homogenisation for 1 min using a polytron, was followed by a washing using 20 mL Tetrahydrofuran and a centrifugation at 7000 G for 5 min. The supernatant was filtrated using absorbent cotton. Then it was filled up to 150 mL using Tetrahydrofuran. 2 mL of this liquid was filled up with 90 mL of purified water, followed by an addition of 30 g sodium chloride. An addition of 30 mL hexane was followed by a shaking for 5 min. Afterwards, the upper layer was filtrated and dehydrated using about 20 g sodium sulfate, anhydrite. Then a concentration to about 5 mL using a rotary evaporator about 40 °C was performed. The resulting liquid was filled up to 10 mL hexane.

Vehicle:

yes

Remarks:

HCO-40

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

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The substance and HCO-40 (10 times amount of the substance) were dissolved in acetone. After acetone was evaporated from it, ionexchanged water was added to prepare 2000 mg/L stock solution
- Controls: Solvent control (HCO-40 was dissolved in ion-exchanged water to prepare 4000 mg/L stock solution)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): NIKKOL HCO-40 (PEG-40 Hydrogenated Castor Oil)
- Concentration of vehicle in test medium (stock solution and final test solution(s) at different concentrations and in control(s)):
Test concentrations: Level 1: 4000 mg vehicle/L
Level 2: 400 mg vehicle/L
Solvent control: 4000 mg vehivle/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Not specified

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp
- Strain: Not specified
- Source: Fukuoka Yabegawa fishery cooperation (Address : 193-1 Ooaza Yamauchi, Yame-shi, Fukuoka 834-0012, Japan)
- Age at study initiation (mean and range, SD): not specified
- Length at study initiation (mean): 9.8 cm
- Weight at study initiation (mean): 22.9 g
- Method of breeding: not specified
- Lipid content at test initiation (mean): 4.2%
- Health status: No visual abnormalities. The fish were checked visually at the delivery and removed those demonstrating any abnormalities. The fish were reared for 6 days in a flow through system following an external disinfection.
- Description of housing/holding area: not specified
- Feeding during test
- Food type: pelleted feed for carp (Nippon Formula Feed Mfg. Co., Ltd.)
- Amount: 2% of total body weight
- Frequency: Twice a day in halves. One the day before fish sampling no food was provided.

ACCLIMATION
- Acclimation period: 28 d
- Acclimation conditions (same as test or not): After rearing, the fish were medicated to eliminate parasites and transferred to an acclimatizing aquarium. After the second external disinfection, they were acclimatized. The fish those demonstrating any abnormalities during this period were removed and reared for 40 days in a flow through system at the temperature of 25 ± 2 °C. The fish were then transferred to test tanks and reared at the same temperature in the flow through system for another 28 days.
- Type and amount of food: not specified
- Feeding frequency: not specified
- Health during acclimation (any mortality observed): not specified

Route of exposure:

aqueous

Justification for method:

aqueous exposure method used for following reason:

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Remarks:

underground water from the premises of Kurume Research Laboratories

Total exposure / uptake duration:

8 wk

Hardness:

117 mg/L

Test temperature:

25 ± 2 °C

pH:

7.0

Dissolved oxygen:

6.8 - 8.1 mg/L

TOC:

0.1 mg/L

Conductivity:

391 µs/cm

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass tank of 70 L
- Type: not specified
- Material, size, headspace, fill volume: glass, 70 L
- Aeration: not specified
- Type of flow-through: not specified
- Renewal rate of test solution: Flow rate: 2 mL/min for stock solution + 800 mL/min dilution water
- No. of organisms per vessel: Level 1 and Level 2: 11 fishes
Solvent control 5 fishes
- No. of vessels per concentration (replicates): 1
- No. of vessels per control / vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Underground water from the premises of Kurume Research Laboratories
- Particulate matter: < 1.0 mg/L suspended solids
- Metals: Alkylmercury: < 0.0005 mg/L
Mercury: < 0.0005 mg/L
Cadmium: < 0.005 mg/L
Cr6+: < 0.02 mg/L
Lead: < 0.005 mg/L
Arsenic: < 0.002 mg/L
Iron: < 0.01 mg/L
Copper: < 0.005 mg/L
- Pesticides: not specified
- Chlorine: < 0.01 mg/L
- Alkalinity: 105 mg/L
- Ca/mg ratio: not specified
- Conductance: 391 µS/cm
- Holding medium different from test medium: not specified
- Intervals of water quality measurement: Once every six month
- Intervals of test medium replacement: 1155 L/day corresponding to 16.5 renewals per 70 L tank per day

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: not specified
- Light intensity: not specified

RANGE-FINDING / PRELIMINARY STUDY
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: 0% mortality at 1000 mg/L
- Other justification for choice of test concentrations: Results of the preliminary study and the analytical detection limits.

Nominal and measured concentrations:

Level 1:
Nominal concentration: 1.0 mg/L
Measured concentration:0.968 - 1.01 mg/L

Level 2:
Nominal concentration: 0.1 mg/L
Measured concentration: 0.0863 - 0.0928 mg/L

Reference substance (positive control):

no

Details on estimation of bioconcentration:

No estimation of bioconcentration performed.

Conc. / dose:

1 mg/L

Temp.:

>= 23 - <= 27 °C

pH:

7

Type:

BCF

Value:

<= 31 dimensionless

Basis:

whole body w.w.

Calculation basis:

other: No test substance determinable in fish.

Remarks:

Duration 8 weeks.

Remarks on result:

other: High concentration - Level 1, 1.0 mg/L (nominal concentration)

Conc. / dose:

0.1 mg/L

Temp.:

>= 23 - <= 27 °C

pH:

7

Type:

BCF

Value:

<= 2.9 dimensionless

Basis:

whole body w.w.

Calculation basis:

other: No test substance determinable in fish.

Remarks:

Duration 8 weeks.

Remarks on result:

other: Low concentration - Level 2, 0.1 mg/L (nominal concentration)

Details on results:

No test substance was determinable in fishes at both levels throughout the test period. Therefore no determination of a discrete BCF value was possible. Nevertheless, an approach assuming the LOD in fish calculates BCF values being equal or lower than 2.9 resp. 31.
- Mortality of test organisms: none observed.
- Behavioural abnormalities: none observed.
- Observations on feeding behavior: not specified
- Observations on body length and weight: not specified
- Reproduction during test period: not specified
- Organ specific bioaccumulation: not specified
- Bound residues forming a plateau: not specified
- Mortality and/or behavioural abnormalities of control: not specified
- Loss of test substance during test period: not specified
- Non-eliminated residues (NER) at the end of elimination phase: not specified
- Results with vehicle control: not specified

Reported statistics:

Determination of BCF
BCF = K/H

where:
H = Average concentration of test substance in test water (mg/L)
K = Concentration of test substance in test fish (µg/g) calculated by:
K = K = {P x (A(t) / A(std) ) / B x D x C / G - E } / F x 100

where:
A : Peak area (pV*sec) (A(std) : Standard solution; A(t) : Sample)
B : Ratio of portion used for analysis
C : Final volume
D : Dilution factor
E : Average concentration of blank in analysis of control
F : Recovery rate
G : Weight of test fish (g)
P : Concentration of test substance in standard solution

Table 1: Results of water analysis

Results of water analysis
Day	Nominal concentration - Level 1	Measured concentration- Level 1	Percentage of nominal concentration - Level 1	Nominal concentration - Level 2	Measured concentration- Level 2	Percentage of nominal concentration - Level 2
d	mg/L	mg/L	%	mg/L	mg/L	%
2	1.000	1.080	108.000	0.1000	0.0764	76.400
7	1.000	0.958	95.800	0.1000	0.0933	93.300
8	1.000	1.010	101.000	0.1000	0.0920	92.000
9	1.000	1.010	101.000	0.1000	0.0836	83.600
20	1.000	1.000	100.000	0.1000	0.1030	103.000
21	1.000	1.000	100.000	0.1000	0.0922	92.200
23	1.000	1.010	101.000	0.1000	0.0912	91.200
27	1.000	0.996	99.600	0.1000	0.0982	98.200
33	1.000	0.922	92.200	0.1000	0.0941	94.100
35	1.000	0.863	86.300	0.1000	0.1010	101.000
37	1.000	0.846	84.600	0.1000	0.0884	88.400
41	1.000	1.030	103.000	0.1000	0.0996	99.600
44	1.000	0.892	89.200	0.1000	0.0882	88.200
48	1.000	0.948	94.800	0.1000	0.0889	88.900
51	1.000	0.963	96.300	0.1000	0.0851	85.100
55	1.000	0.958	95.800	0.1000	0.0922	92.200
Mean values		0.968	96.788		0.092	91.713

 

Table 2: Results of fish analysis

Results of fish analysis
Week	Measured concentration- Level 1	Measured concentration- Level 2
wk	mg/L	mg/L
2	n.d.	n.d.
	n.d.	n.d.
4	n.d.	n.d.
	n.d.	n.d.
6	n.d.	n.d.
	n.d.	n.d.
8	n.d.	n.d.
	n.d.	n.d.

n.d. = not determinable

 

Table 3: Validity criteria for OECD 305 (2012)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The temperature variation is less than ± 2 °C	25±2 °C	Yes
The concentration of dissolved oxygen does not fall below 60% saturation	≥ 86 %	Yes
The concentration of the test substance in the chambers is maintained within ± 20% of the mean of the measured values during the uptake phase	91.7 - 96.8 %	Yes
The concentration of the test substance is below its limit of solubility in water, taking into account the effect that the test water may have on effective solubility	No determination of water solubility was possible.	No assessable
The mortality or other adverse effects/disease in both control and treated fish is less than 10% at the end of the test; where the test is extended over several weeks or months, death or other adverse effects in both sets of fish should be less than 5% per month and not exceed 30% in all.	No mortality observed	Yes

 

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

The substance is not fully compliant with the applicability domain of the model. However, this calculation is used in a weight of evidence approach, in accordance to the REACh Regulation (EC) No 1907/2006, Annex XI General rules for adaptation of the standard testing regime set out in Annexes VII to X, 1.2. It is adequately documented and justified. For more detail see field `overall remarks, attachments´.

Justification for type of information:

1. SOFTWARE
Vega version 1.1.5

2. MODEL (incl. version number)
CAESAR v 2.1.14

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: Vega v1.1.5
- Model(s) used: CAESAR BCF Model version 2.1.14

Full reference and details of the used formulas can be found in:
Zhao, C., Boriani, E., Chana, A., Roncaglioni,A., Benfenati, E. A new hybrid system of QSAR models for predicting bioconcentration factors (BCF). Chemosphere (2008), 73, 1701-1707.
Lombardo A, Roncaglioni A, Boriani E, Milan C, Benfenati E. Assessment and validation of the CAESAR predictive model for bioconcentration factor (BCF) in fish. Chemistry Central Journal (2010), 4 (Suppl 1).
R. Todeschini and V. Consonni (2009) Molecular Descriptors for Chemoinformatics, Wiley-VCH U.S.

- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Vehicle:

no

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Justification for method:

minimised test method used to support BCF estimates based on QSAR

Test type:

other: calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: Vega version 1.1.5, CAESAR v 2.1.14
- Result based on measured log Pow of: 7.9

Type:

BCF

Value:

9 L/kg

Basis:

whole body w.w.

Type:

other: Log BCF

Value:

0.97 dimensionless

Basis:

whole body w.w.

For detailed information on the results please refer to the attached report.

Reference 3

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

The substance is not fully compliant with the applicability domain of the model. However, this calculation is used in a weight of evidence approach, in accordance to the REACh Regulation (EC) No 1907/2006, Annex XI General rules for adaptation of the standard testing regime set out in Annexes VII to X, 1.2. It is adequately documented and justified. For more detail see field `overall remarks, attachments´.

Justification for type of information:

1. SOFTWARE
Vega version 1.1.5

2. MODEL (incl. version number)
BCF Meylan Model v1.0.3

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: Vega v1.1.5
- Model(s) used: BCF Meylan Model version 1.0.3

Full reference and details of the used formulas can be found in:
Meylan W.M., Howard P.H., Boethling R.S. et al. Improved Method for Estimating Bioconcentration / Bioaccumulation Factor from Octanol/Water
Partition Coefficient. 1999, Environ. Toxicol. Chem. 18(4): 664-672

- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Vehicle:

no

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Justification for method:

minimised test method used to support BCF estimates based on QSAR

Test type:

other: calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: Vega version 1.1.5, Meylan Model version 1.0.3
- Result based on calculated log Pow of: 16.06

Type:

BCF

Value:

3 L/kg

Basis:

whole body w.w.

Type:

other: Log BCF

Value:

0.5 dimensionless

Basis:

whole body w.w.

For detailed information on the results please refer to the attached report.

Reference 4

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

The substance is not fully compliant with the applicability domain of the model. However, this calculation is used in a weight of evidence approach or as a supporting study, in accordance to the REACh Regulation (EC) No 1907/2006, Annex XI General rules for adaptation of the standard testing regime set out in Annexes VII to X, 1.2. It is adequately documented and justified. For more details, see field “overall remarks, attachments”.

Justification for type of information:

1. SOFTWARE
Vega version 1.1.5

2. MODEL (incl. version number)
BCF model (Arnot-Gobas) v1.0.0

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information on materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in the "Overall remarks, attachments" section.

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: Vega v1.1.5
- Model(s) used: Arnot-Gobas v1.0.0
Full reference and details of the used formulas can be found in:
1. Arnot JA, Gobas FAPC. 2003. A generic QSAR for assessing the bioaccumulation potential of organic chemicals in aquatic food webs. QSAR and Combinatorial Science 22: 337-345.
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Vehicle:

no

Test organisms (species):

other: Fish

Route of exposure:

other: aqueous and dietary

Test type:

other: calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: Vega v1.1.5, BCF model (Arnot-Gobas) v1.0.0
- Result based on calculated log Pow of: 16.06

Type:

BCF

Value:

0.89 L/kg

Basis:

whole body w.w.

Remarks on result:

other: including biotransformation, upper trophic

Type:

other: log BCF

Value:

-0.05 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: including biotransformation, upper trophic

For detailed information on the results please refer to the attached report.

Description of key information

Based on the low BCF from an available bioaccumulation study using aquatic exposure, the mitigating properties of the molecule, its very high log Kow and the result of QSAR model calculations, the substance has only a very low potential for bioaccumulation through aquatic exposure.

Additional information

Foundation

According to Annex XI of Regulation (EC) No 1907/2006 a registrant may adapt the standard testing regime in accordance with the general rules set out in Section 1 of this Annex. One possibility is to submit a weight of evidence from several independent sources of information leading to the assumption/conclusion that a substance has or has not a particular dangerous property, while the information from each single source alone is regarded insufficient to support this notion. Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available further testing on vertebrate animals for that property shall be omitted or further testing not involving vertebrate animals may be omitted. This approach is considered appropriate for the assessment of the bioaccumulation potential of Sumilizer GP.

 

Log Kow

The log Kow was calculated using KOWWIN 1.6 implemented in EpiSuite as 16.5. According to ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.11: Endpoint specific guidance (2017), a substance is unlikely to meet the B criterion (i.e. unlikely to have a BCF > 2,000) if the calculated log Kow is higher than 10. Therefore, based on the log Kow the substance has a low potential of bioaccumulation.

 

Experimental data bioaccumulation

Experimental data on bioaccumulation of the substance is available, based on a study of Yakata (1999) performed similar to OECD TG 305C (1981). During this study fishes were exposed to two concentration levels (1 mg/L and 0.1 mg/L) of the test substance in a flow-through system for a period of 8 weeks. The average substance concentration in the test medium remained between 80% and 120% during the course if the study. Every two weeks, two fishes per concentration level were removed and the content of test substance determined. The concentration of test substance in the fishes stay below the limit of determination (2.8 µg/g fish) in both concentration levels at every sampling date. Deviations to the current guideline occurred during the course of this study, 2 instead of 4 fishes were samples each sampling date. A dispersant was used for addition of the test substance into the test medium. As no water solubility was determined, it may be, that the concentration of test substance in test medium is higher than the maximum water solubility. However, these deviations do not invalidate the study. As a clear result, no bioaccumulation through aquatic exposure into fishes was observed. Thus, the lower amount of sampled fishes did not influence the outcome of the study. The substance concentration potentially higher than its solubility in the test medium did not falsely decrease the determined BCF values, as no test substance was determinable in the test fishes.

Based on the outcome of the study, no bioaccumulation potential is expected through aquatic exposure.

 

QSAR

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort. According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labelling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

To support the hypothesis, that the evaluated substance has not bioaccumulative properties, its BCF was predicted using different QSAR approaches recommended in ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7c: Endpoint specific guidance (2017), Table R.7.10-1.

 

The BCF Meylan Model v1.0.3 implemented in VEGA v1.1.5 is based on the method proposed by Meylan et al. implemented in the EPI Suite BCFBAF module. The model provides a BCF prediction based on different regression equations or fixed values, selected on the basis of an initial classification between ionic and non-ionic compounds, and on the value of the predicted logP value. The logP prediction is provided by the VEGA logP model. The original dataset from EPI Suite has been taken, then processed and cleared from duplicates and compounds provided with structure that had problems. The determined log BCF was 0.5. Based on the recommendations of the model, the result has a low reliability, based on the AD Index =0, on a scale from 0 (not reliable) to 1 (reliable) shows the questionable assessment of the model. In the current case, the AD Index of 0 is based on the very low reliability of the estimated log Kow (logP in report). Nevertheless, the very high value for log Kow (16.06) is reasonable based on the absence of strong polar fragments. Therefore, and since the results are used in the frame of a weight of evidence approach, in accordance to Annex XI of Regulation (EC) 1907/2006, it is considered adequate for assessment.

 

The BCF CAESAR model v2.1.14 implemented in VEGA v1.1.5 provides a quantitative prediction of bioconcentration factor (BCF) in fish, given in log(L/kg). It is implemented inside the VEGA online platform, accessible at: http://www.vega-qsar.eu. The model extends the original CAESAR model, freely available at:http://www.caesarproject.eu/software/. The determined log BCF was 0.97. Based on the recommendations of the model, the result has a low reliability, based on the AD Index = 0, on a scale from 0 (not reliable) to 1 (reliable) shows the questionable assessment of the model. In the current case, the AD Index of 0 is based on the high log Kow (logP in report), which is outside the log Kow range of the model (log Kow 0 - 6). Nevertheless, the high value for log Kow (7.9) is reasonable based on the absence of strong polar fragments. Therefore, and since the results are used in the frame of a weight of evidence approach, in accordance to Annex XI of Regulation (EC) No 1907/2006, it is considered adequate for assessment.

 

The Arnot-Gobas model v1.0.0 implemented in VEGA v1.1.5 estimates steady-state bioconcentration factor (BCF; L/kg) and bioaccumulation factor (BAF; L/kg) values for non-ionic organic chemicals in three general trophic levels of fish (i.e., lower, middle and upper) in temperate environments. The model calculations represent general trophic levels (i.e., not for a particular fish species) and are derived for “representative” environmental conditions (e.g., dissolved and particulate organic carbon content in the water column, water temperature). Thus, it provides general estimates for these conditions in absence of site-specific measurements or estimates. The determined log BCF was -0.05. Based on the recommendations of the model, the result has a low reliability, based on the AD Index = 0.284, on a scale from 0 (not reliable) to 1 (reliable) shows the questionable assessment of the model. In the current case, the AD Index of 0 is based on the very low reliability of the estimated log Kow (logP in report). Nevertheless, the very high value for log Kow (16.06) is reasonable based on the absence of strong polar fragments. Therefore, and since the results are used in the frame of a weight of evidence approach, in accordance to Annex XI of Regulation (EC) No 1907/2006, it is considered adequate for assessment.

 

The BCF model (KNN/Read-Across) 1.1.0 implemented VEGA in v1.1.5 could not perform an assessment. Thus, it was not used for the determination of the bioaccumulation potential in this weight-of-evidence approach.

 

All evaluated models clearly indicate the very low bioaccumulation potential of the substance due to the determined very low BCF values. As all models are out of the applicability domain, the values are used only in this weight-of-evidence approach. Although the substance is not within the applicability domain of the three used models, this approach is regarded as a worst-case scenario as all experimental BCF values for the respective three nearest neighbours were lower or at least in the same range than the predicted BCF for the respective model. Thus, it can be anticipated that the BCF value will even be lower than the predicted (low) BCF value.

 

Conclusion

Based on an available bioaccumulation study using aquatic exposure, the structural properties of the molecule like its very high log Kow and the result of QSAR model calculations the substance has only a very low potential for bioaccumulation.