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Bioaccumulation: aquatic / sediment

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Endpoint:
bioaccumulation in aquatic species: fish
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
KL2 due to RA
Justification for type of information:
Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification.
Qualifier:
according to
Guideline:
EPA OPP 165-4 (Laboratory Studies of Pesticide Accumulation in Fish)
Deviations:
no
GLP compliance:
yes
Radiolabelling:
yes
Details on sampling:
- A stock solution of 2.4 mg/mL was formulated by mixing radiolabeled test substance with unlabeled test substance and diluting with water.
- Following dilution with unlabeled test substance, the percent radiolabeled test substance in the mixture was 0.337 or 0.00337 as a decimal. On a combined test substance basis (both labeled and unlabeled) the calculated specific activity was 227013 dpmug x 0.00337 = 765.03 dpm/ug
Test organisms (species):
Lepomis macrochirus
Details on test organisms:
Test organism:
- Common name: Bluegill
- Strain: SLS Lot 88A9
- Source: Froma culture maintained at Springborn Life Sciences, Inc.
- Length at study initiation (lenght definition, mean, range and SD): 65 mm
- Weight at study initiation (mean and range, SD): 3.6g
- Health status: Normal and healthy
- Frequency: Daily

Acclimation:
- Acclimation period: 14d prior to test initiation
- Acclimation conditions (same as test or not): Yes
- Type and amount of food: Dry pelleted food, ad libitum, daily throughout the 14d period, except 24h before testing.
Route of exposure:
aqueous
Test type:
flow-through
Water / sediment media type:
natural water: freshwater
Total exposure / uptake duration:
ca. 35 d
Total depuration duration:
ca. 21 d
Hardness:
22-32 mg/L CaCO3
Test temperature:
16-21°C
pH:
6.7-7.6
Dissolved oxygen:
6.2 -10.1 mg/L (64-94% of saturation)
Details on test conditions:
Test system
- Test vessel: 76 x 40 x 30 cm aquaria
- Type (delete if not applicable): Open
- Material, size, headspace, fill volume: 75L
- Renewal rate of test solution (frequency/flow rate): 4-4.7 tank volume replacements/d; 2L water to each aquaria at an average rate of 375 times/d
- No. of organisms per vessel: 190
- Biomass loading rate: 0.91 g/L/day

Test medium / Water parameters:
- Source/preparation of dilution water: Dilution water used for this test was from the same source as the water which flowed into the fish holding tank and was characterised weekly.
- Alkalinity: 21-24 mg/L CaCO3
- Conductance: 100-130 umhos/cm

Other test conditions:
- Photoperiod: 16h light/ 8h dark

Sampling period:
- To monitor initial concentration of 14C residues in water: 5 mL of samples were collected on Days 4, 3, 2, and 1 before introduction of fish
- To monitor concentration of 14C residues in water during the test: 5 mL of samples were collected on Days 1, 3, 7, 8, 9, 10, 14, 21, 23, 28 and 35 of exposure
- To quantify the accumulation and elimination of 14C residues in the edible, non-edible tissue of fish: 5 fish were collected, eviscerated and filleted on Day 1, 3, 7, 10, 14, 21, 28 and 35 of exposure.
- To quantify background 14C residues of test substance: 5 control fish were also collected, eviscerated and filleted on Day 35 of exposure and Day 21 of depuration.
- To estimate the half-life of the accumulated 14C residue present in the fish during depuration period: Water and tissue samples were collected from the tankon Day 1, 3, 7, 10, 14, 16 and 21 of depuration. Five fish were collected at each interval for analysis.

Others:
- Steady state was determined by measuring 14C residue conc. for 3 consecutive sampling intervals.
- After 35d of exposure, 35 of remaining fish in the treatment aquarium were transferred to a clean aquarium into which untreated dilution water was introduced at a rate equal to flow rate during exposure.
- Triplicate edible fish tissue samples from Day 35 of exposure were prepared for a hexane and methanol extraction procedure.
- To estimate the amount of 14C residues bound to the external surface of the skin of fish: 10 fish were removed after 35 d of exposure, eviscerated, filleted and the muscle portions were scraped off the skin. The skin portions were subsequently combustible to determine the residue conc. of the test substance.
Nominal and measured concentrations:
Nominal concentration: 0.05 mg/L
Measured concentration: 0.076 mg/L
Details on estimation of bioconcentration:
BCF factors for edible, non-edible and whole body fish tissue were determined by dividing the mean measured equilibrium 14C tissue concentration for each tissue type by the mean measured water concentration for the entire exposure period. For comparison, an additonal method of calculating BCF factors wher the ratio of the uptake constant (Ku) to the depuration constant (Kd) was utilized. i.e.,
BCF = Ku/Kd

Key result
Type:
BCF
Value:
79 dimensionless
Basis:
whole body w.w.
Calculation basis:
other: mean
Remarks on result:
other: predicted BCF (calculated using uptake and depuration constants) = 110
Remarks:
conc. in environment / dose: 0.076 mg/L
Key result
Type:
BCF
Value:
160 dimensionless
Basis:
non-edible fraction
Calculation basis:
other: mean
Remarks on result:
other: predicted BCF = 190
Remarks:
conc. in environment / dose: 0.076 mg/L
Key result
Type:
BCF
Value:
33 dimensionless
Basis:
edible fraction
Calculation basis:
other: mean
Remarks on result:
other: predicted BCF = 50
Remarks:
conc. in environment / dose: 0.076 mg/L
Key result
Elimination:
yes
Parameter:
DT50
Depuration time (DT):
21 d
Details on results:
- Mortality of test organisms: two treated fish (in a population of 190) died
- Behavioural abnormalities: None

Exposure phase:
- The mean 14C residues measured in the edible tissue reached steady state on Day 14 and remained relatively constant throughout the remainder of the exposure (mean range 2.10-3.36 mg/kg).
- Mean steady state conc. in edible tissue and mean conc. in the water during the period 0-35d: 2.54±0.67 mg/kg and 0.076±0.024 mg/L. The mean steady state BCF factor in the edible tissue during the 35d of exposure was determined to be 33X.
- The mean 14C residues measured in the non-edible tissue reached steady state on Day 14 and ranged from 11-13 mg/kg during the remainder of the 35-d exposure.
- Mean steady state in non-edible tissue and mean conc. in the water during the period 0-35 d: 12±2.3 mg/kg and 0.076±0.024 mg/L. The mean steady state BCF factor in the non-edible tissue during the 35d of exposure was determined to be 160X.
- The mean steady state conc. of 14C residue conc. in whole fish and mean conc. in the water during the period 0.35 d: 6±1.5 mg/kg and 0.076±0.024 mg/L.. The mean steady state BCF factor in the whole body of fish during the 35d of exposure was determined to be 79X.
- The residues in control were below the detectable level; small residues seen were due to contamination.
- Analytical results of the polar (methanol) solvent and non-polar (hexane) solvent extractions of edible tissue samples revealed 11% of the 14C residues accumulated in the exposure were extractable with methanol, 2.4% with hexane and 75% were not extractable with either solvent.

Depuration phase:
- Analyses of the tissues during the depuration phase indicated that in each case there was a continuous elimination of 14C residues from the respective tissues over the course of the 21d depuration period.
- Concentration of 14C residues present in the water of the depuration aquarium remained <= 0.014 mg/L, the limit of radiometric detection throughout the 21d depuration period.
- Half-life for non-edible tissue was: Between Days 14 and 21. By Day 21, the fish had eliminated 29%, 60% and 44% of the 14C residues that had been present on the last day of exposure on each of the tissues (i.e., edible, non-edible and whole body tissues respectively).
- Half-life based on model calculations (using 1st order kinetics) were: 16, 10 and 12d for edible, non-edible and whole body tissues respectively.
- The conc. of the residual test substance on the skin was observed to be higher than those found in the total edible tissue (skin and muscle combined) indicating significant binding of the test substance to skin and scales of fish.


Given the known strong affinity for the cationic compounds like the test substance to bind to essentially all surfaces, a logical explanation for the observed slow depuration is that the 14C residues are strongly bound to surfaces exposed to the treated water, e.g., gills, skin and intestine. The phenomenon has been clearly demonstrated with other quarternary ammonium compounds.

Validity criteria fulfilled:
not specified
Conclusions:
Under the study conditions, the whole body BCF of the read across substance was determined to be 79, indicating low potential to bioaccumulate.
Executive summary:

A study was conducted to determine the aquatic bioaccumulation of the read across substance, C12 -16 ADBAC (30.64% active; 98.9% radiolabeled purity) in Lepomis macrochirus (bluegill fish) under flow-through conditions, according to EPA OPP 165-4, in compliance with GLP. The blue gill fish were continuously exposed to a nominal concentration of 0.050 mg/L of the read across substance (equivalent to a measured concentration of 0.076 mg/L) in well water for 35 days, followed by transfer of 35 fish into flowing uncontaminated water for a 21-d depuration period. Sampling was carried out on Days 0, 1, 3, 7, 9, 10, 14, 21, 23, 28 and 35 for the exposure period and Days 1, 3, 7, 10, 14 and 21 for the depuration period. Water samples were collected on Day 8 of the exposure period and Day 16 of the depuration for analytic determination of the read across substance concentration. Radiometric analyses of the water and selected fish tissues revealed that the mean steady state bioconcentration factor (BCF) in the edible, non-edible and whole-body fish tissue during the 35 days of exposure to be 33, 160 and 79 L/kg. The half-life for non-edible tissue was attained between Days 14 and 21, while it could not be reached for the edible and whole-body fish tissues by the end of 21-d depuration period. By Day 21 of the depuration period, the 14C residues present on the last day of exposure in the edible, non-edible and whole-body fish tissues had been eliminated by 29, 60 and 44% respectively. Analysis of skin tissue after 35 d of exposure showed residue levels somewhat higher than those observed for edible tissue at the same sampling period, indicating that there is likely significant binding of 14C-ADBAC to the skins and scales of exposed bluegill, as expected behaviour of cationic surfactants. Under the conditions of the study, the whole body BCF of the read across substance was determined to be 79, indicating low potential to bioaccumulate (Fackler, 1989). Based on the results of the read across study, a similar low bioaccumulation potential is expected for the test substance.

Endpoint:
bioaccumulation in aquatic species: fish
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
13 Jan 2020
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
QSAR prediction from a well-known and acknowledged tool. See below under "attached background material section" for methodology and QPRF
Qualifier:
according to
Guideline:
other: REACH Guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals
Principles of method if other than guideline:
The Bioconcentration factor (BCF) value was predicted for the test substance using BCFBAF v3.02 program of EPI Suite v 4.11. Since the test substance is an UVCB containing ionic and non-ionic constituents, the BCF values were predicted using regression-based and Arnot-Gobas BAF-BCF models respectively and using SMILES codes as the input parameter.
Justification for method:
other:
Details on estimation of bioconcentration:
The Bioconcentration factor (BCF) value was calculated for the test substance using BCFBAF v3.02 program of EPI Suite v 4.11. Since the test substance is an UVCB containing ionic and non-ionic constituents, the BCF values were predicted using regression-based and Arnot-Gobas BAF-BCF models respectively and using SMILES codes as the input parameter.
Key result
Type:
BCF
Value:
ca. 3.16 - ca. 275.3 other: L/Kg ww
Basis:
whole body w.w.
Calculation basis:
other: regression-based method and Arnot-gobas based method for ionic and non-ionic respectively
Remarks on result:
other: low bioaccumulation potential
Key result
Type:
BCF
Value:
72.62 other: L/Kg ww
Basis:
whole body w.w.
Remarks:
(weighted average value)
Calculation basis:
other: regression-based method and Arnot-gobas based method for ionic and non-ionic respectively
Remarks on result:
other: low bioaccumulation potential

Predicted value:

The estimated BCF values for the different constituents using the regression-based equation and Arnot-Gobas methods were as follows:

SMILES Constituents/Carbon chain length Concentration range (%) Mole fraction Xi = (mi/Mi)/∑ (mi/Mi) BCF (L/kg wet-wt)
BCFBAF (regression based)
BCF (L/kg wet-wt)
BCFBAF (Arnot-Gobas methodology based)
BCF x Xi
(L/kg wet-wt)
BCFBAF
Domain evaluation
[Cl-].CCCCCCCC[N+](C)(C)C C8 ≤ 10  6.72E-03 3.16 - 2.12E-02 MW, Log KOW (ID)
[Cl-].CCCCCCCCCC[N+](C)(C)C C10 ≤ 10  5.92E-03 3.16 - 1.87E-02 MW, Log KOW (ID)
[Cl-].CCCCCCCCCCCC[N+](C)(C)C C12 45 - 75  6.24E-01 70.8 - 4.42E+01 MW, Log KOW (ID)
[Cl-].CCCCCCCCCCCCCC[N+](C)(C)C C14 10 - 40 2.34E-01 70.8 - 1.66E+01 MW, Log KOW (ID)
[Cl-].CCCCCCCCCCCCCCCC[N+](C)(C)C C16 ≤ 15  6.11E-02 70.8 - 4.32E+00 MW, Log KOW (ID)
[Cl-].CCCCCCCCCCCCCCCCCC[N+](C)(C)C C18 ≤ 10  4.01E-02 70.8 - 2.84E+00 MW, Log KOW (ID)
[Cl-].CCCCCCCC\C=C\CCCCCCCC[N+](C)(C)C C18' ≤ 10  4.03E-03 70.8 - 2.86E-01 MW, Log KOW (ID)
CCCCCCCCCCCCN(C)C Amines, coco alkyldimethyl ≤ 5  1.31E-02 - 275.3 3.60E+00 MW, Log KOW, Corr. Fac (ID)
C(CCCCCCCCCCC)N(C)(C)Cl Cocodimethylammonium chloride 1.12E-02 70.8 - 7.94E-01 MW, Log KOW (ID)
      1.00E+00 BCF=   72.62  
        Log BCF   1.86  

Details on resullt      
       
C8 TMAC SMILES : CCCCCCCCN(CL)(C)(C)C Domain evaluation
CHEM  : 
MOL FOR: C11 H26 CL1 N1  MW Max
MOL WT : 207.79 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 0.50 (BCF = 3.16 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.0768 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): -0.04 (BAF = 0.908 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : -0.74  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: -0.74
Equation Used to Make BCF estimate:
  Log BCF = 0.50 (Ionic; Log Kow dependent)
  Estimated Log BCF = 0.500 (BCF = 3.162 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 7 | -CH2- [linear]                          | 0.0242 | 0.1693
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow = -0.74 (KowWin estimate)       | 0.3073 | -0.2287
 MolWt| * | Molecular Weight Parameter               |        | -0.5328
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -1.1147
  RESULT  |           Bio Half-Life (days)           |        | 0.07679
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 9.027 /day (10 gram fish) 
 kM (Rate Constant): 5.076 /day (100 gram fish) 
 kM (Rate Constant): 2.855 /day (1 kg fish) 
 kM (Rate Constant): 1.605 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = -0.042 (BCF = 0.9075 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = -0.042 (BAF = 0.9075 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = -0.026 (BCF = 0.9422 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = -0.026 (BAF = 0.9422 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = -0.022 (BCF = 0.9498 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = -0.022 (BAF = 0.9498 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = -0.040 (BCF = 0.9123 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = -0.040 (BAF = 0.9125 L/kg wet-wt)
 
C10 TMAC SMILES : CCCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C13 H30 CL1 N1  MW Max
MOL WT : 235.84 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 0.50 (BCF = 3.16 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.146 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 0.02 (BAF = 1.05 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 0.24  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 0.24
Equation Used to Make BCF estimate:
  Log BCF = 0.50 (Ionic; Log Kow dependent)
  Estimated Log BCF = 0.500 (BCF = 3.162 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 9 | -CH2- [linear]                          | 0.0242 | 0.2177
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  0.24 (KowWin estimate)       | 0.3073 | 0.0732
 MolWt| * | Molecular Weight Parameter               |        | -0.6048
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -0.8364
  RESULT  |           Bio Half-Life (days)           |        | 0.1457
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 4.756 /day (10 gram fish) 
 kM (Rate Constant): 2.674 /day (100 gram fish) 
 kM (Rate Constant): 1.504 /day (1 kg fish) 
 kM (Rate Constant): 0.8457 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 0.021 (BCF = 1.051 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.021 (BAF = 1.051 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 0.018 (BCF = 1.041 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 0.018 (BAF = 1.041 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 0.016 (BCF = 1.037 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 0.016 (BAF = 1.037 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 0.033 (BCF = 1.078 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.034 (BAF = 1.081 L/kg wet-wt)
C12 TMAC SMILES : CCCCCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C15 H34 CL1 N1  MW Max
MOL WT : 263.90 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.277 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 0.40 (BAF = 2.5 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 1.22  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 1.22
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 11 | -CH2- [linear]                          | 0.0242 | 0.2661
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  1.22 (KowWin estimate)       | 0.3073 | 0.3751
 MolWt| * | Molecular Weight Parameter               |        | -0.6767
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -0.5581
  RESULT  |           Bio Half-Life (days)           |        | 0.2766
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 2.506 /day (10 gram fish) 
 kM (Rate Constant): 1.409 /day (100 gram fish) 
 kM (Rate Constant): 0.7924 /day (1 kg fish) 
 kM (Rate Constant): 0.4456 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 0.398 (BCF = 2.5 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.398 (BAF = 2.5 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 0.304 (BCF = 2.016 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 0.304 (BAF = 2.016 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 0.278 (BCF = 1.896 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 0.278 (BAF = 1.896 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 0.426 (BCF = 2.67 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.431 (BAF = 2.696 L/kg wet-wt)
 
C14 TMAC SMILES : CCCCCCCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C17 H38 CL1 N1  MW Max
MOL WT : 291.95 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.525 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 1.21 (BAF = 16.1 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 2.20  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 2.20
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 13 | -CH2- [linear]                          | 0.0242 | 0.3144
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  2.20 (KowWin estimate)       | 0.3073 | 0.6770
 MolWt| * | Molecular Weight Parameter               |        | -0.7487
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -0.2798
  RESULT  |           Bio Half-Life (days)           |        |  0.525
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 1.32 /day (10 gram fish) 
 kM (Rate Constant): 0.7424 /day (100 gram fish) 
 kM (Rate Constant): 0.4175 /day (1 kg fish) 
 kM (Rate Constant): 0.2348 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 1.206 (BCF = 16.07 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 1.206 (BAF = 16.07 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 1.051 (BCF = 11.26 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 1.051 (BAF = 11.26 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 1.002 (BCF = 10.06 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 1.003 (BAF = 10.06 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 1.254 (BCF = 17.94 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 1.267 (BAF = 18.5 L/kg wet-wt)
C16 TMAC SMILES : CCCCCCCCCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C19 H42 CL1 N1  MW Max
MOL WT : 320.01 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 1.03 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 2.10 (BAF = 127 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 3.18  ID 11.26
Log Kow (experimental): 3.23
Log Kow used by BCF estimates: 3.23
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 15 | -CH2- [linear]                          | 0.0242 | 0.3628
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  3.23 (experimental  )       | 0.3073 | 0.9927
 MolWt| * | Molecular Weight Parameter               |        | -0.8206
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | 0.0124
  RESULT  |           Bio Half-Life (days)           |        |  1.029
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 0.6736 /day (10 gram fish) 
 kM (Rate Constant): 0.3788 /day (100 gram fish) 
 kM (Rate Constant): 0.213 /day (1 kg fish) 
 kM (Rate Constant): 0.1198 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 2.103 (BCF = 126.8 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 2.103 (BAF = 126.8 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 1.988 (BCF = 97.37 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 1.989 (BAF = 97.49 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 1.946 (BCF = 88.24 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 1.948 (BAF = 88.7 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 2.259 (BCF = 181.5 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 2.348 (BAF = 222.7 L/kg wet-wt)
       
C18 TMAC SMILES : CCCCCCCCCCCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C21 H46 CL1 N1  MW Max
MOL WT : 348.06 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 1.89 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 2.72 (BAF = 524 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 4.17  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 4.17
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 17 | -CH2- [linear]                          | 0.0242 | 0.4112
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  4.17 (KowWin estimate)       | 0.3073 | 1.2807
 MolWt| * | Molecular Weight Parameter               |        | -0.8925
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | 0.2768
  RESULT  |           Bio Half-Life (days)           |        |  1.892
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 0.3665 /day (10 gram fish) 
 kM (Rate Constant): 0.2061 /day (100 gram fish) 
 kM (Rate Constant): 0.1159 /day (1 kg fish) 
 kM (Rate Constant): 0.06517 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 2.718 (BCF = 522.6 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 2.719 (BAF = 524 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 2.717 (BCF = 520.8 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 2.725 (BAF = 530.4 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 2.704 (BCF = 505.6 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 2.728 (BAF = 534.9 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 3.175 (BCF = 1495 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 3.634 (BAF = 4301 L/kg wet-wt)
C18' TMAC SMILES : CCCCCCCCC=CCCCCCCCCN(CL)(C)(C)C
CHEM  : 
MOL FOR: C21 H44 CL1 N1  MW Max
MOL WT : 346.04 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 2.32 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 2.68 (BAF = 479 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 3.95  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 3.95
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 4 | Methyl [-CH3]                           | 0.2451 | 0.9804
 Frag | 15 | -CH2- [linear]                          | 0.0242 | 0.3628
 Frag | 2 | -C=CH [alkenyl hydrogen]                | 0.0988 | 0.1977
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 Frag | 2 | -C=CH [alkenyl hydrogen]                | 0.0000 | 0.0000
 L Kow| * | Log Kow =  3.95 (KowWin estimate)       | 0.3073 | 1.2146
 MolWt| * | Molecular Weight Parameter               |        | -0.8874
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | 0.3652
  RESULT  |           Bio Half-Life (days)           |        |  2.319
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 0.299 /day (10 gram fish) 
 kM (Rate Constant): 0.1681 /day (100 gram fish) 
 kM (Rate Constant): 0.09454 /day (1 kg fish) 
 kM (Rate Constant): 0.05316 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 2.679 (BCF = 477.6 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 2.680 (BAF = 478.7 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 2.622 (BCF = 418.4 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 2.628 (BAF = 424.1 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 2.593 (BCF = 391.4 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 2.609 (BAF = 406.6 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 2.968 (BCF = 929.4 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 3.300 (BAF = 1997 L/kg wet-wt)
Amines, coco alkyldimethyl SMILES : CCCCCCCCCCCCN(C)C
CHEM  : 
MOL FOR: C14 H31 N1  MW Max
MOL WT : 213.41 ID 959.17
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.88 (BCF = 76.3 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.692 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 2.44 (BAF = 277 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 5.44  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 5.44
Equation Used to Make BCF estimate:
  Log BCF = 0.6598 log Kow - 0.333 + Correction
     Correction(s):                   Value Corr. Instance
      Alkyl chains (8+ -CH2- groups) -1.374 ID 1
  Estimated Log BCF = 1.882 (BCF = 76.29 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 1 | Tertiary amine                           | -0.7829 | -0.7829
 Frag | 3 | Methyl [-CH3]                           | 0.2451 | 0.7353
 Frag | 11 | -CH2- [linear]                          | 0.0242 | 0.2661
 L Kow| * | Log Kow =  5.44 (KowWin estimate)       | 0.3073 | 1.6722
 MolWt| * | Molecular Weight Parameter               |        | -0.5473
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -0.1596
  RESULT  |           Bio Half-Life (days)           |        | 0.6925
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 1.001 /day (10 gram fish) 
 kM (Rate Constant): 0.5629 /day (100 gram fish) 
 kM (Rate Constant): 0.3165 /day (1 kg fish) 
 kM (Rate Constant): 0.178 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 2.440 (BCF = 275.3 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 2.443 (BAF = 277.3 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 2.573 (BCF = 374.4 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 2.625 (BAF = 422.1 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 2.613 (BCF = 410.6 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 2.834 (BAF = 682.4 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 4.165 (BCF = 1.463e+004 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 5.720 (BAF = 5.242e+005 L/kg wet-wt)
       
Cocodimethylammonium chloride SMILES : C(CCCCCCCCCCC)N(C)(C)CL    
CHEM  : 
MOL FOR: C14 H31 CL1 N1  MW Max
MOL WT : 248.86 ID 991.8
--------------------------------- BCFBAF v3.01 --------------------------------
Summary Results:
 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)
 Biotransformation Half-Life (days) : 0.117 (normalized to 10 g fish)
 Log BAF (Arnot-Gobas upper trophic): 0.12 (BAF = 1.3 L/kg wet-wt)
 
=============================
BCF (Bioconcentration Factor):
============================= log Kow Max
Log Kow (estimated) : 0.67  ID 11.26
Log Kow (experimental): not available from database
Log Kow used by BCF estimates: 0.67
Equation Used to Make BCF estimate:
  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)
  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)
===========================================================
Whole Body Primary Biotransformation Rate Estimate for Fish:
===========================================================
------+-----+--------------------------------------------+---------+---------
 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE  
------+-----+--------------------------------------------+---------+---------
 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341
 Frag | 3 | Methyl [-CH3]                           | 0.2451 | 0.7353
 Frag | 11 | -CH2- [linear]                          | 0.0242 | 0.2661
 Frag | 1 | Quaternary amine                         | 0.0000 | 0.0000
 L Kow| * | Log Kow =  0.67 (KowWin estimate)       | 0.3073 | 0.2069
 MolWt| * | Molecular Weight Parameter               |        | -0.6382
 Const| * | Equation Constant                        |        | -1.5371
============+============================================+=========+=========
  RESULT  |       LOG Bio Half-Life (days)           |        | -0.9329
  RESULT  |           Bio Half-Life (days)           |        | 0.1167
  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |
============+============================================+=========+=========
Biotransformation Rate Constant:
 kM (Rate Constant): 5.939 /day (10 gram fish) 
 kM (Rate Constant): 3.34 /day (100 gram fish) 
 kM (Rate Constant): 1.878 /day (1 kg fish) 
 kM (Rate Constant): 1.056 /day (10 kg fish) 
Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):
  Estimated Log BCF (upper trophic) = 0.115 (BCF = 1.305 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.115 (BAF = 1.305 L/kg wet-wt)
  Estimated Log BCF (mid trophic)  = 0.088 (BCF = 1.224 L/kg wet-wt)
  Estimated Log BAF (mid trophic)  = 0.088 (BAF = 1.224 L/kg wet-wt)
  Estimated Log BCF (lower trophic) = 0.079 (BCF = 1.2 L/kg wet-wt)
  Estimated Log BAF (lower trophic) = 0.079 (BAF = 1.2 L/kg wet-wt)
 
Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):
  Estimated Log BCF (upper trophic) = 0.145 (BCF = 1.397 L/kg wet-wt)
  Estimated Log BAF (upper trophic) = 0.147 (BAF = 1.404 L/kg wet-wt)
 
Validity criteria fulfilled:
not applicable
Conclusions:
Using the regression-based and Arnot-gobas based methods of the BCFBAF v.3.02 program (EPI SuiteTM v4.11) for ionic and non-ionic constituents respectively, the BCF values were predicted to range from 3.16 to 275.3 L/kg ww (weighted average: 72.62 L/Kg ww).
Executive summary:

The Bioconcentration factor (BCF) value of test substance, C12-18 TMAC was predicted using regression-based and Arnot-Gobas BAF-BCF models of BCFBAF v3.02 program (EPI SuiteTMv4.11). The Arnot-Gobas method, takes into account mitigating factors, like growth dilution and metabolic biotransformations, therefore the BCF values using this method is considered to be more realistic or accurate. Therefore, except for ionic, pigments and dyes, perfluorinated substances, for which it is not recommended (as of now), the Arnot-Gobas method is used preferentially used for BCF predictions. Considering that the test substance is an UVCB containing majorly ionic (e.g., (e.g., the quaternary ammonium salts) and few non-ionic constituents (e.g., amines), the BCF values were predicted using regression-based and Arnot-Gobas BAF-BCF models respectively and using SMILES codes as the input parameter. The BCF values for the constituents ranged from 3.16 to 275.3 L/kg ww (log BCF: 0.50 to 2.44), indicating a low bioaccumulation potential. On comparing with domain descriptors, all constituents were found to meet the MW, log Kow and/or maximum number of correction factor instances domain criteria as defined in the BCFBAF user guide of EPISuite. Further, given that the major constituents are structurally very similar and vary only in the carbon chain length, a weighted average value, which takes into account the percentage of the constituent in the substance, has been considered to dampen the errors in predictions (if any). Therefore, the weighted average BCF value was calculated as 72.62 L/Kg ww (Log BCF = 1.86). Overall, considering either the individual BCF predictions for the constituents or the weighted average values, the test substance is expected to have a low bioaccumulation potential. However, taking into consideration the model’s training set and validation set statistics and the fact that the training set only contains 61 ionic compounds, the BCF predictions for the individual constituents are considered to be reliable with moderate confidence.

Description of key information

The results of the read across study, supported with the estimated BCF value for the test substance together with its ionic nature indicates a low bioaccumulation potential. The experimental BCF value of 79 L/kg wt-wt from the read across study has been considered further for hazard/risk assessment

Key value for chemical safety assessment

BCF (aquatic species):
79 L/kg ww

Additional information

Study 1: A study was conducted to determine the aquatic bioaccumulation of the read across substance, C12 -16 ADBAC (30.64% active; 98.9% radiolabeled purity) in Lepomis macrochirus (bluegill fish) under flow-through conditions, according to EPA OPP 165-4, in compliance with GLP. The blue gill fish were continuously exposed to a nominal concentration of 0.050 mg/L of the read across substance (equivalent to a measured concentration of 0.076 mg/L) in well water for 35 days, followed by transfer of 35 fish into flowing uncontaminated water for a 21-d depuration period. Sampling was carried out on Days 0, 1, 3, 7, 9, 10, 14, 21, 23, 28 and 35 for the exposure period and Days 1, 3, 7, 10, 14 and 21 for the depuration period. Water samples were collected on Day 8 of the exposure period and Day 16 of the depuration for analytic determination of the read across substance concentration. Radiometric analyses of the water and selected fish tissues revealed that the mean steady state bioconcentration factor (BCF) in the edible, non-edible and whole-body fish tissue during the 35 days of exposure to be 33, 160 and 79 L/kg. The half-life for non-edible tissue was attained between Days 14 and 21, while it could not be reached for the edible and whole-body fish tissues by the end of 21-d depuration period. By Day 21 of the depuration period, the 14C residues present on the last day of exposure in the edible, non-edible and whole-body fish tissues had been eliminated by 29, 60 and 44% respectively. Analysis of skin tissue after 35 d of exposure showed residue levels somewhat higher than those observed for edible tissue at the same sampling period, indicating that there is likely significant binding of 14C-ADBAC to the skins and scales of exposed bluegill, as expected behaviour of cationic surfactants. Under the conditions of the study, the whole body BCF of the read across substance was determined to be 79, indicating low potential to bioaccumulate (Fackler, 1989).

Study 2: The Bioconcentration factor (BCF) value of test substance, C12-18 TMAC was predicted using regression-based and Arnot-Gobas BAF-BCF models of BCFBAF v3.02 program (EPI SuiteTMv4.11). The Arnot-Gobas method, takes into account mitigating factors, like growth dilution and metabolic biotransformations, therefore the BCF values using this method is considered to be more realistic or accurate. Therefore, except for ionic, pigments and dyes, perfluorinated substances, for which it is not recommended (as of now), the Arnot-Gobas method is used preferentially used for BCF predictions. Considering that the test substance is an UVCB containing majorly ionic (e.g., (e.g., the quaternary ammonium salts) and few non-ionic constituents (e.g., amines), the BCF values were predicted using regression-based and Arnot-Gobas BAF-BCF models respectively and using SMILES codes as the input parameter. The BCF values for the constituents ranged from 3.16 to 275.3 L/kg ww (log BCF: 0.50 to 2.44), indicating a low bioaccumulation potential. On comparing with domain descriptors, all constituents were found to meet the MW, log Kow and/or maximum number of correction factor instances domain criteria as defined in the BCFBAF user guide of EPISuite. Further, given that the major constituents are structurally very similar and vary only in the carbon chain length, a weighted average value, which takes into account the percentage of the constituent in the substance, has been considered to dampen the errors in predictions (if any). Therefore, the weighted average BCF value was calculated as 72.62 L/Kg ww (Log BCF = 1.86). Overall, considering either the individual BCF predictions for the constituents or the weighted average values, the test substance is expected to have a low bioaccumulation potential. However, taking into consideration the model’s training set and validation set statistics and the fact that the training set only contains 61 ionic compounds, the BCF predictions for the individual constituents are considered to be reliable with moderate confidence.

This is further supported by the no bioaccumulation potential evidence observed in in the two toxicokinetic studies in mammals with the read across substance, C12 -16 ADBAC (Selim, 1987 and Appelqvist, 2006). .

Also, the biocides assessment reports available from RMS Italy on Coco TMAC and C12-16 ADBAC, concluded the substances to show low potential for bioaccumulation, based on the results from the above study (Fackler, 1989) and an additional read across to DDAC for the Coco TMAC's assessment ((ECHA biocides assessment report, 2015, 2016). The report concluded the following in the Coco TMAC assessment report:Coco alkyltrimethylammonium chloride is readily biodegradable, is rapidly excreted and does not accumulate in mammals, and it adsorbs onto the fish surface where its irritating action is expressed (therefore accumulation is more related to the concentration of the administered solution). Based on these properties’ bioaccumulation is not expected to be of concern for ATMAC/TMAC. An experimental BCFwhole body of 81 L/kg was determined in a flow-through test with Lepomis machrochirus and the read across substance DDAC (Lonza Cologne GmbH and Akzo Nobel Surface Chemistry AB, same study). A very similar result was obtained for the other quaternary ammonium compound benzyl-C12-16-alkyldimethyl ammonium chloride (C12-16-BKC/ADBAC) in a fish bioconcentration test, which gave a BCFwhole body = 79 L/kg (Akzo Nobel Surface Chemistry AB, access to Lonza Cologne GmbH study). Being both studies equally reliable, the BCFwhole body = 81 L/kg is chosen because related to the lead read across substance (DDAC) and it is slightly higher than the C12-16 BKC/ADBAC endpoint.”

Overall, the results of the read across study, supported with the estimated BCF value for the test substance together with its ionic nature indicates a low bioaccumulation potential. The experimental BCF value of 79 L/kg wt-wt from the read across study has been considered further for hazard/risk assessment.