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Bioaccumulation: aquatic / sediment

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Endpoint:
bioaccumulation in aquatic species, other
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Validated QSAR model
Principles of method if other than guideline:
Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
GLP compliance:
no
Test organisms (species):
other: Fish
Route of exposure:
aqueous
Test type:
other: calculation
Water / sediment media type:
natural water: freshwater
Type:
BCF
Value:
3.47
Basis:
whole body w.w.
Remarks on result:
other: Regression based estimate
Details on results:
For detailed description on the model and its applicability, see "Any other information on materials and methods incl. tables".

BCFBAF Program (v3.01) Results:

==============================

SMILES : O=C(NCCCCCCCCC=CCCCCCCCC)CCCCCCCCCCCCCCC

CHEM : Hexadecanamide, N-9-octadecenyl-, (Z)-

MOL FOR: C34 H67 N1 O1

MOL WT : 505.92

--------------------------------- BCFBAF v3.01 ----------------------------

----

Summary Results:

Log BCF (regression-based estimate): 0.54 (BCF = 3.47 L/kg wet-wt)

Biotransformation Half-Life (days) : 267 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 0.83 (BAF = 6.72 L/kg wet-wt)

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 14.31

Equation Used to Make BCF estimate:

Log BCF = -0.49 log Kow + 7.554 + Correction

Correction(s): Value

No Applicable Correction Factors

Estimated Log BCF = 0.541 (BCF = 3.473 L/kg wet-wt)

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+-------

--

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+-------

--

Frag | 2 | Linear C4 terminal chain [CCC-CH3] | 0.0341 | 0.0682

Frag | 1 | Amide [-C(=O)-N or -C(=S)-N] | -0.5952 | -0.5952

Frag | 2 | Methyl [-CH3] | 0.2451 | 0.4902

Frag | 29 | -CH2- [linear] | 0.0242 | 0.7014

Frag | 2 | -C=CH [alkenyl hydrogen] | 0.0988 | 0.1977

Frag | 2 | -C=CH [alkenyl hydrogen] | 0.0000 | 0.0000

L Kow| * | Log Kow = 14.31 (KowWin estimate) | 0.3073 | 4.3990

MolWt| * | Molecular Weight Parameter | | -1.2973

Const| * | Equation Constant | | -1.5058

============+============================================+=========+=======

==

RESULT | LOG Bio Half-Life (days) | | 2.4269

RESULT | Bio Half-Life (days) | | 267.2

NOTE | Bio Half-Life Normalized to 10 g fish at 15 deg C |

============+============================================+=========+=======

==

Biotransformation Rate Constant:

kM (Rate Constant): 0.002594 /day (10 gram fish)

kM (Rate Constant): 0.001459 /day (100 gram fish)

kM (Rate Constant): 0.0008202 /day (1 kg fish)

kM (Rate Constant): 0.0004612 /day (10 kg fish)

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = -0.048 (BCF = 0.8946 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 0.828 (BAF = 6.724 L/kg wet-wt)

Estimated Log BCF (mid trophic) = -0.030 (BCF = 0.9338 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 0.564 (BAF = 3.666 L/kg wet-wt)

Estimated Log BCF (lower trophic) = -0.026 (BCF = 0.9427 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 0.400 (BAF = 2.513 L/kg wet-wt)

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = -0.047 (BCF = 0.8971 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 1.341 (BAF = 21.94 L/kg wet-wt)

Endpoint:
bioaccumulation in aquatic species, other
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Validated QSAR model
Principles of method if other than guideline:
Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
GLP compliance:
no
Test organisms (species):
other: Fish
Route of exposure:
aqueous
Test type:
other: calculation
Water / sediment media type:
natural water: freshwater
Type:
BCF
Value:
0.89 L/kg
Basis:
whole body w.w.
Remarks on result:
other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

BCFBAF Program (v3.01) Results:

==============================

SMILES : O=C(NCCCCCCCCC=CCCCCCCCC)CCCCCCCCCCCCCCC

CHEM : Hexadecanamide, N-9-octadecenyl-, (Z)-

MOL FOR: C34 H67 N1 O1

MOL WT : 505.92

--------------------------------- BCFBAF v3.01 ----------------------------

----

Summary Results:

Log BCF (regression-based estimate): 0.54 (BCF = 3.47 L/kg wet-wt)

Biotransformation Half-Life (days) : 267 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 0.83 (BAF = 6.72 L/kg wet-wt)

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 14.31

Equation Used to Make BCF estimate:

Log BCF = -0.49 log Kow + 7.554 + Correction

Correction(s): Value

No Applicable Correction Factors

Estimated Log BCF = 0.541 (BCF = 3.473 L/kg wet-wt)

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+-------

--

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+-------

--

Frag | 2 | Linear C4 terminal chain [CCC-CH3] | 0.0341 | 0.0682

Frag | 1 | Amide [-C(=O)-N or -C(=S)-N] | -0.5952 | -0.5952

Frag | 2 | Methyl [-CH3] | 0.2451 | 0.4902

Frag | 29 | -CH2- [linear] | 0.0242 | 0.7014

Frag | 2 | -C=CH [alkenyl hydrogen] | 0.0988 | 0.1977

Frag | 2 | -C=CH [alkenyl hydrogen] | 0.0000 | 0.0000

L Kow| * | Log Kow = 14.31 (KowWin estimate) | 0.3073 | 4.3990

MolWt| * | Molecular Weight Parameter | | -1.2973

Const| * | Equation Constant | | -1.5058

============+============================================+=========+=======

==

RESULT | LOG Bio Half-Life (days) | | 2.4269

RESULT | Bio Half-Life (days) | | 267.2

NOTE | Bio Half-Life Normalized to 10 g fish at 15 deg C |

============+============================================+=========+=======

==

Biotransformation Rate Constant:

kM (Rate Constant): 0.002594 /day (10 gram fish)

kM (Rate Constant): 0.001459 /day (100 gram fish)

kM (Rate Constant): 0.0008202 /day (1 kg fish)

kM (Rate Constant): 0.0004612 /day (10 kg fish)

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = -0.048 (BCF = 0.8946 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 0.828 (BAF = 6.724 L/kg wet-wt)

Estimated Log BCF (mid trophic) = -0.030 (BCF = 0.9338 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 0.564 (BAF = 3.666 L/kg wet-wt)

Estimated Log BCF (lower trophic) = -0.026 (BCF = 0.9427 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 0.400 (BAF = 2.513 L/kg wet-wt)

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = -0.047 (BCF = 0.8971 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 1.341 (BAF = 21.94 L/kg wet-wt)

Endpoint:
bioaccumulation in aquatic species: fish
Type of information:
experimental study
Remarks:
Study ongoing, experimental phase completed
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -III: Dietary Exposure Bioaccumulation Fish Test
Version / remarks:
ON GOING
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Radiolabelling:
yes
Details on sampling:
- Sampling intervals/frequency for test organisms: day 0, 14 (uptake phase), 15, 18, 21, 28, 35, 42 (depuration phase)
- Sampling intervals/frequency for test medium samples: day 0, 14 (uptake phase)
- Sample storage conditions before analysis: chilled conditions
- Details on sampling and analysis of test organisms and test media samples: Food samples: extraction with tetrahydrofuran, vortex mixing for 1 min, sonication for 15 min, centrifugation at 3000 rpm for 15 min. Fish samples: homogenization by mincing with scissors, extraction with tetrahydrofuran by mixing with a blender for 5 min, sonication for 5 min. centrifugation at 2500 rpm for 15 min.
Vehicle:
yes
Remarks:
corn oil
Details on preparation of test solutions, spiked fish food or sediment:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: evaporation to dryness and solution in corn oil
- Controls: corn oil without test substance
- Concentration of vehicle in test medium: Test substance: 2.49 mL corn oil in 120.06 g food; Control: 2.4 mL corn oil in 120.16 g food
- Evidence of undissolved material: none reported

PREPARATION OF SPIKED FISH FOOD
- Details on fish food: Inicio 917 1.1 mm trout pellets (Biomar, Denmark) (50% protein and 16% fat content)
- Details of spiking: test substance dissolved in corn oil
- Quantity of corn oil vehicle per unit mass of fish food: Test substance: 2.49 mL corn oil in 120.06 g food; Control: 2.4 mL corn oil in 120.16 g food
- Method of mixing: manual shaking followed by rotational agitation for 5 min
Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
TEST ORGANISM
- Common name: rain bow trout
- Source: Commcercial supplier, UK
- Length at study initiation: mean 8.13 cm
- Weight at study initiation: mean 5.37 g
- Weight at termination (mean and range, SD): 5.28 - 9.66 g
- Lipid content at test initiation: 4.26% (tissue weight)
- Health status: no abnormalities reported
- Description of housing/holding area: same as test, acclimatization for at least 2 weeks
- Feeding during test
- Food type: Inicio 917 1.1 mm trout pellets (Biomar, Denmark)
- Amount: 2% of body weight (on day 27 2.7% were fed in error)
- Frequency: daily

ACCLIMATION
- Acclimation period: at least 2 weeks
- Acclimation conditions: same as test
- Type and amount of food: Inicio 917 1.1 mm trout pellets (Biomar, Denmark)
- Feeding frequency: daily
- Health during acclimation: no mortality reported
Route of exposure:
feed
Justification for method:
dietary exposure method used because stable, measurable water concentrations cannot be maintained
Test type:
flow-through
Water / sediment media type:
natural water: freshwater
Total exposure / uptake duration:
14 d
Total depuration duration:
28 d
Hardness:
174 - 176 mg CaCO3
Test temperature:
13.9 - 14.3°C
pH:
7.6 - 8.1
Dissolved oxygen:
72 - 95% air saturation
TOC:
<1.0 - 1.3 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: aquaria
- Material, fill volume: glass, 100 L
- Aeration: continuous aeration
- Renewal rate of test solution: nominal 800 mL/min equal to approximately 1152 L per d
- No. of organisms per vessel: 50
- No. of vessels per concentration: 1
- No. of vessels per control / vehicle control: 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water, dechlorinated by activated carbon, softened to the desired water hardness
- Metals: none
- Pesticides: none
- Chlorine: none
- Holding medium different from test medium: no
- Intervals of water quality measurement: pH, oxygen, temperature daily

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/ 8 h dark, with 20 min dawn and dusk transition periods
- Overall daily feeding rate used in the study: 2 % body weight, adjusted after every sampling interval (on day 27 erroneously 2.7% was fed)
- Number of feeds per day: 1

RANGE-FINDING / PRELIMINARY STUDY
The solubility in the vehicle corn oil was determined with nominal test substance concentrations of 10, 100, 1000 µg/g. The 1000 µg/g concentration contained undissolved material, while the lower concentrations were observed to be clear.

The homogeneity of the test substance on food was tested with the concentrations 10, 100 µg/g. The test substance dissolved in corn oil was administered to fish food same as in the test five times. The test substance concentrations were in the range of ±15%.

The palability of treated food was determined for 7 days. The feeding was considered to be normal. With a test substance concentration of 100 µg/g, radioactivity in fish was in the range of 1.05 - 1.91 µg equivalents/g after 7 d. This was determined to be sufficient for measuring a 95% reduction in body burden. Therefore, the concentration of 100 µg/g food was chosen for the test.
Nominal and measured concentrations:
Nominal 0 (control), 100 µg test substance/g food
Measured at d0: 0 (control), 112 µg/g
Measured at d14: 0 (control), 104 µg/g
Reference substance (positive control):
no
Lipid content:
5.33 %
Time point:
other: end of depuration
Lipid content:
4.65 %
Time point:
end of exposure
Remarks on result:
other: end of uptake/start of depuration
Lipid content:
4.26 %
Time point:
start of exposure
Type:
BMF
Value:
0.039 dimensionless
Metabolites:
2 metabolites could be identified:
M1: Palmitic acid, C16H32O2
M2: C32H63O3N

Table 1: Validity criteria for OECD 305-III









































Criterion from the guideline



Outcome



Validity criterion fulfilled



The temperature variation is less than ± 2 °C



13.9 – 14.3°C



yes



The concentration of dissolved oxygen does not fall below 60% saturation



≥72%



yes



The concentration of the test substance in fish food before and at the end of the uptake phase is within a range of ± 20% (based on at least three samples at both time points)



104 – 112 % recovery



yes



The homogeneity of test item in feed is confirmed to be less than ±15 % from the


mean (by analysis at least triplicate portions)



109%



yes



Concentrations of test substance are not detected, or are present only at typical trace levels, in un-spiked food or control fish tissues relative to treated samples



No test substance in untreated food or control fish reported



yes



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 or adverse effects reported



yes



 


further information will be given after finalization of the study report

Validity criteria fulfilled:
yes
Remarks:
see Table 1 in "Any other information on results incl. tables" for further details

Description of key information

Key value for chemical safety assessment

Additional information

Experimental data on bioaccumulation of (Z)-N-Octadec-9-enylhexadecan-1-amide (CAS No. 16260-09-6) is not available yet, but an OECD 305 by dietary route is currently on-going. The evaluation of the bioaccumulation potential of the substance is therefore based on all available related data. This is 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, to cover the data requirements of Regulation (EC) No. 1907/2007 Annex IX and X (Guidance on information requirements and chemical safety assessment Chapter R.7c: Endpoint specific guidance, R.7.11.5.3, page 123 ff (ECHA, 2012)).

The bioaccumulation potential of a substance is driven by the physic-chemical properties of the substance triggering the bioavailability as well as by metabolism and excretion. As the test substance is highly insoluble in water (< 0.01 mg/L) the bioavailability of the substance in water is negligible. Though the substance has a high partition coefficient (log Kow of > 5.7) indicating the potential to bioaccumulate a significant accumulation is not expected based on the environmental fate and on BCF/BAF calculation.

The log Koc values of > 5 indicates that the substance will adsorb to suspended organic particles, dissolved organic matter and to some degree biota in the aquatic environment. If available, a potential uptake of the substance by organisms of the pelagic zone is expected to occur mainly via food ingestion since the substance may adsorb to solid particles.

Despite that the substance is not readily biodegradable elimination in sewage treatment plants is expected due to the high adsorption potential and the very low water solubility. Insoluble substances are largely removed in the primary settling tank and fat trap during the clarification and sedimentation process of waste water treatment (according to the Guidance on information requirements and chemical safety assessment, Chapter R7. b (ECHA, 2012)). Only small amounts of the substance may enter the secondary treatment and thus get in contact with activated sludge. Due to the high log Koc calculated for the substance components an extensive adsorption to sewage sludge is expected. Thus the substances is expected to be removed from the water column to a significant degree (Guidance on information requirements and chemical safety assessment, Chapter R.7a (ECHA, 2012)). Thus a significant uptake of the substance by aquatic organisms through the water phase is not expected. Considering this, one can assume that the availability of the substance in the aquatic environment is generally very low, which reduces the probability of uptake by aquatic organisms

This assumption is supported by QSAR calculations using BCFBAF v3.01. BCF/BAF values calculated for the substance exhibit a low bioaccumulation potential (Knoell Consult GmbH, 2012). A calculated BCF/BAF of 0.89 L/kg (SRC BCFBAF v3.01 Arnot Gobas, upper trophic level) indicates that the substance has a low bioaccumulation potential.

But it supports the tendency that substances with high log Kow values have a lower potential for bioconcentration as summarized in the ECHA Guidance R.11 (ECHA, 2012) and they are not expected to meet the B/vB criterion, which is also in accordance with Annex IX of Regulation (EC) No 1907/2006.

The substance is characterised by a low water solubility and high log Koc leading to a low bioavailability. Due to its higher molecular weight, no extensive metabolism of the substance is expected but rather direct elimination. In conclusion, a bioaccumulation or biomagnification through the food chain of the substance is not expected. It can hence be concluded that the high log Kow, which indicates a potential for bioaccumulation, overestimates the bioaccumulation potential of the substance.